Two new integral formulae for the Beta function - Manuel Ortigueira (International Journal of Applied Mathematics, 2005)
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Write-read-erase molecular-switching system trapped in a polymer hydrogel matrix - Galindo, F; J. C. Lima; Luis, SV; A. J. Parola; Pina, F (Advanced Functional Materials, 2005)
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A zinc(II)-based receptor for ATP binding and hydrolysis - Bazzicalupi, C; Bencini, A; Bianchi, A; Danesi, A.; Giorgi, C; Lodeiro, C.; Pina, F; Santarelli, S.; Valtancoli, B (Chemical Communications, 2005)
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Times Cited: 32 Pina, Fernando/C-8161-2011; Lodeiro, Carlos/B-4793-2013; REQUIMTE, AL/H-9106-2013; REQUIMTE, PHOTO/M-4229-2013; REQUIMTE, C4O/M-5599-2013; REQUIMTE, UCIBIO/N-9846-2013; REQUIMTE, LAQV/N-9835-2013 Pina, Fernando/0000-0001-8529-6848; Lodeiro, Carlos/0000-0001-5582-5446; 32

Considerations about the choice of a differintegrator - Manuel Ortigueira; J.A. Tenreiro-Machado; J. Sá da Costa (International Conference on Computacional Cybernetics, 2004)
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Considerations about the choice of a differintegrator - Ortigueira, M.; J.A. Tenreiro-Machado; J. Sá da Costa (International Conference on Computacional Cybernetics, 2004)
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New Insights into Pseudo-Fractional ARMA Modelling - Manuel Ortigueira; Serralheiro, A.J. (International Conference on Computacional Cybernetics, 2004)
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New Insights into Pseudo-Fractional ARMA Modelling - Ortigueira, M.; Serralheiro, A.J. (International Conference on Computacional Cybernetics, 2004)
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Paracoccus pantotrophus pseudoazurin is an electron donor to cytochrome c peroxidase - Pauleta, S. R.; Guerlesquin, F.; Goodhew, C. F.; Devreese, B.; Van Beeumen, J.; Pereira, A. S.; Moura, I.; Pettigrew, G. W. (Biochemistry, 2004)
The gene for pseudoazurin was isolated from Paracoccus pantotrophus LMD 52.44 and expressed in a heterologous system with a yield of 54.3 mg of pure protein per liter of culture. The gene and protein were shown to be identical to those from P. pantotrophus LMD 82.5. The extinction coefficient of the protein was re-evaluated and was found to be 3.00 mM(-1) cm(-1) at 590 nm. It was confirmed that the oxidized protein is in a weak monomer/dimer equilibrium that is ionic- strength-dependent. The pseudoazurin was shown to be a highly active electron donor to cytochrome c peroxidase, and activity showed an ionic strength dependence consistent with an electrostatic interaction. The pseudoazurin has a very large dipole moment, the vector of which is positioned at the putative electron-transfer site, His81, and is conserved in this position across a wide range of blue copper proteins. Binding of the peroxidase to pseudoazurin causes perturbation of a set of NMR resonances associated with residues on the His81 face, including a ring of lysine residues. These lysines are associated with acidic residues just back from the rim, the resonances of which are also affected by binding to the peroxidase. We propose that these acidic residues moderate the electrostatic influence of the lysines and so ensure that specific charge interactions do not form across the interface with the peroxidase.
Times Cited: 23

Influence of storage solution on enamel demineralization submitted to pH cycling - Moura, J. S.; Rodrigues, L. K.; Del Bel Cury, A. A.; Lima, E. M.; Garcia, R. M. (J Appl Oral Sci, 2004)
Extracted human teeth are frequently used for research or educational purposes. Therefore, it is necessary to store them in disinfectant solutions that do not alter dental structures. Thus, this study evaluated the influence of storage solution on enamel demineralization. For that purpose, sixty samples were divided into the following groups: enamel stored in formaldehyde (F1), stored in thymol (T1), stored in formaldehyde and submitted to pH cycling (F2), stored in thymol and submitted to pH cycling (T2). All samples were evaluated by cross-sectional microhardness analysis and had their percentage of mineral volume versus micrometer (integrated area) determined. Differences between groups were found up to 30-microm depth from the enamel surface (p < 0.05), where samples from group T2 were more demineralized. It was concluded that the storage solution influenced the reaction of a dental substrate to a cariogenic challenge, suggesting that formaldehyde may increase enamel resistance to demineralization, when compared to demineralization occurring in enamel stored in thymol solution.
1678-7757 (Print)1678-7757 (Linking)Journal Article

Mo and W bis-MGD enzymes: nitrate reductases and formate dehydrogenases - Moura, J. J.; Brondino, C. D.; Trincao, J.; Romao, M. J. (J Biol Inorg Chem, 2004)
Molybdenum and tungsten are second- and third-row transition elements, respectively, which are found in a mononuclear form in the active site of a diverse group of enzymes that generally catalyze oxygen atom transfer reactions. Mononuclear Mo-containing enzymes have been classified into three families: xanthine oxidase, DMSO reductase, and sulfite oxidase. The proteins of the DMSO reductase family present the widest diversity of properties among its members and our knowledge about this family was greatly broadened by the study of the enzymes nitrate reductase and formate dehydrogenase, obtained from different sources. We discuss in this review the information of the better characterized examples of these two types of Mo enzymes and W enzymes closely related to the members of the DMSO reductase family. We briefly summarize, also, the few cases reported so far for enzymes that can function either with Mo or W at their active site.
0949-8257 (Print)0949-8257 (Linking)Journal ArticleResearch Support, Non-U.S. Gov'tReview
Keywords: Electron Transport; Formate Dehydrogenases/*chemistry/classification/*metabolism; Molybdenum/*analysis; Nitrate Reductase; Nitrate Reductases/*chemistry/classification/*metabolism; Tungsten/*analysis

Overexpression and purification of Treponema pallidum rubredoxin; kinetic evidence for a superoxide-mediated electron transfer with the superoxide reductase neelaredoxin - Auchere, F.; Sikkink, R.; Cordas, C.; Raleiras, P.; Tavares, P; Moura, I.; Moura, J. J. (J Biol Inorg Chem, 2004)
Superoxide reductases are a class of non-haem iron enzymes which catalyse the monovalent reduction of the superoxide anion O2- into hydrogen peroxide and water. Treponema pallidum (Tp), the syphilis spirochete, expresses the gene for a superoxide reductase called neelaredoxin, having the iron protein rubredoxin as the putative electron donor necessary to complete the catalytic cycle. In this work, we present the first cloning, overexpression in Escherichia coli and purification of the Tp rubredoxin. Spectroscopic characterization of this 6 kDa protein allowed us to calculate the molar absorption coefficient of the 490 nm feature of ferric iron, epsilon=6.9+/-0.4 mM(-1) cm(-1). Moreover, the midpoint potential of Tp rubredoxin, determined using a glassy carbon electrode, was -76+/-5 mV. Reduced rubredoxin can be efficiently reoxidized upon addition of Na(2)IrCl(6)-oxidized neelaredoxin, in agreement with a direct electron transfer between the two proteins, with a stoichiometry of the electron transfer reaction of one molecule of oxidized rubredoxin per one molecule of neelaredoxin. In addition, in presence of a steady-state concentration of superoxide anion, the physiological substrate of neelaredoxin, reoxidation of rubredoxin was also observed in presence of catalytic amounts of superoxide reductase, and the rate of rubredoxin reoxidation was shown to be proportional to the concentration of neelaredoxin, in agreement with a bimolecular reaction, with a calculated k(app)=180 min(-1). Interestingly, similar experiments performed with a rubredoxin from the sulfate-reducing bacteria Desulfovibrio vulgaris resulted in a much lower value of k(app)=4.5 min(-1). Altogether, these results demonstrated the existence for a superoxide-mediated electron transfer between rubredoxin and neelaredoxin and confirmed the physiological character of this electron transfer reaction.
0949-8257 (Print)0949-8257 (Linking)Journal Article
Keywords: Bacterial Proteins; Cloning, Molecular; Electrochemistry; Electron Transport; Genetic Vectors/genetics; Iron-Binding Proteins/chemistry/*metabolism; Kinetics; Oxidoreductases/chemistry/*metabolism; Rubredoxins/genetics/*isolation & purification/*metabolism; Spectrum Analysis; Superoxide Dismutase; Superoxides/*metabolism; Treponema pallidum/genetics/*metabolism

Overexpression and purification of Treponema pallidum rubredoxin; kinetic evidence for a superoxide-mediated electron transfer with the superoxide reductase neelaredoxin - Auchere, F.; Sikkink, R.; Cordas, C.; Raleiras, P.; Tavares, P; Moura, I.; Moura, J. J. G. (JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY, 2004)
Superoxide reductases are a class of non-haem iron enzymes which catalyse the monovalent reduction of the superoxide anion O-2(-) into hydrogen peroxide and water. Treponema pallidum (Tp), the syphilis spirochete, expresses the gene for a superoxide reductase called neelaredoxin, having the iron protein rubredoxin as the putative electron donor necessary to complete the catalytic cycle. In this work, we present the first cloning, overexpression in Escherichia coli and purification of the Tp rubredoxin. Spectroscopic characterization of this 6 Da protein allowed us to calculate the molar absorption coefficient of the 490 nm feature of ferric iron, epsilon=6.9+/-0.4 mM(-1) cm(-1). Moreover, the midpoint potential of Tp rubredoxin, determined using a glassy carbon electrode, was -76+/-5 mV. Reduced rubredoxin can be efficiently reoxidized upon addition of Na2IrCl6-oxidized neelaredoxin, in agreement with a direct electron transfer between the two proteins, with a stoichiometry of the electron transfer reaction of one molecule of oxidized rubredoxin per one molecule of neelaredoxin. In addition, in presence of a steady-state concentration of superoxide anion, the physiological substrate of neelaredoxin, reoxidation of rubredoxin was also observed in presence of catalytic amounts of superoxide reductase, and the rate of rubredoxin reoxidation was shown to be proportional to the concentration of neelaredoxin, in agreement with a bimolecular reaction, with a calculated k(app)=180 min(-1). Interestingly, similar experiments performed with a rubredoxin from the sulfate-reducing bacteria Desulfovibrio vulgaris resulted in a much lower value of k(app)=4.5 min(-1). Altogether, these results demonstrated the existence for a superoxide-mediated electron transfer between rubredoxin and neelaredoxin and confirmed the physiological character of this electron transfer reaction.
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A copper protein and a cytochrome bind at the same site on bacterial cytochrome c peroxidase - Pauleta, S. R.; Cooper, A.; Nutley, M.; Errington, N.; Harding, S.; Guerlesquin, F.; Goodhew, C. F.; Moura, I.; Moura, J. J.; Pettigrew, G. W. (Biochemistry, 2004)
Pseudoazurin binds at a single site on cytochrome c peroxidase from Paracoccus pantotrophus with a K(d) of 16.4 microM at 25 degrees C, pH 6.0, in an endothermic reaction that is driven by a large entropy change. Sedimentation velocity experiments confirmed the presence of a single site, although results at higher pseudoazurin concentrations are complicated by the dimerization of the protein. Microcalorimetry, ultracentrifugation, and (1)H NMR spectroscopy studies in which cytochrome c550, pseudoazurin, and cytochrome c peroxidase were all present could be modeled using a competitive binding algorithm. Molecular docking simulation of the binding of pseudoazurin to the peroxidase in combination with the chemical shift perturbation pattern for pseudoazurin in the presence of the peroxidase revealed a group of solutions that were situated close to the electron-transferring heme with Cu-Fe distances of about 14 A. This is consistent with the results of (1)H NMR spectroscopy, which showed that pseudoazurin binds closely enough to the electron-transferring heme of the peroxidase to perturb its set of heme methyl resonances. We conclude that cytochrome c550 and pseudoazurin bind at the same site on the cytochrome c peroxidase and that the pair of electrons required to restore the enzyme to its active state after turnover are delivered one-by-one to the electron-transferring heme.
0006-2960 (Print)0006-2960 (Linking)Journal ArticleResearch Support, Non-U.S. Gov't
Keywords: Azurin/*analogs & derivatives/*chemistry/metabolism; Bacterial Proteins/chemistry/metabolism; Binding, Competitive; Calorimetry; Centrifugation; Centrifugation, Density Gradient; Computer Simulation; Copper/*chemistry; Cytochrome c Group/*chemistry/metabolism; Cytochrome-c Peroxidase/*chemistry/metabolism; Macromolecular Substances/chemistry/metabolism; Metalloproteins/*chemistry/metabolism; Models, Molecular; Nuclear Magnetic Resonance, Biomolecular; Paracoccus pantotrophus/*enzymology/metabolism; Protein Binding; Thermodynamics

Decavanadate as a biochemical tool in the elucidation of muscle contraction regulation - Tiago, T.; Aureliano, M.; Moura, J. J. (J Inorg Biochem, 2004)
Recently reported decameric vanadate (V(10)) high affinity binding site in myosin S1, suggests that it can be used as a tool in the muscle contraction regulation. In the present article, it is shown that V(10) species induces myosin S1 cleavage, upon irradiation, at the 23 and 74 kDa sites, the latter being prevented by actin and the former blocked by the presence of ATP. Identical cleavage patterns were found for meta- and decavanadate solutions, indicating that V(10) and tetrameric vanadate (V(4)) have the same binding sites in myosin S1. Concentrations as low as 50 muM decavanadate (5 muM V(10) species) induces 30% of protein cleavage, whereas 500 muM metavanadate is needed to attain the same extent of cleavage. After irradiation, V(10) species is rapidly decomposed, upon protein addition, forming vanadyl (V(4+)) species during the process. It was also observed by NMR line broadening experiments that, V(10) competes with V(4) for the myosin S1 binding sites, having a higher affinity. In addition, V(4) interaction with myosin S1 is highly affected by the products release during ATP hydrolysis in the presence or absence of actin, whereas V(10) appears to be affected at a much lower extent. From these results it is proposed that the binding of vanadate oligomers to myosin S1 at the phosphate loop (23 kDa site) is probably the cause of the actin stimulated myosin ATPase inhibition by the prevention of ATP/ADP exchange, and that this interaction is favoured for higher vanadate anions, such as V(10).
0162-0134 (Print)0162-0134 (Linking)In VitroJournal ArticleResearch Support, Non-U.S. Gov't
Keywords: Animals; Kinetics; Magnetic Resonance Spectroscopy; Muscle Contraction/*drug effects/physiology/radiation effects; Muscle, Skeletal/*drug effects/physiology/radiation effects; Rabbits; Spectrophotometry; Vanadates/*pharmacology

Antagonists Mo and Cu in a heterometallic cluster present on a novel protein (orange protein) isolated from Desulfovibrio gigas - Bursakov, S. A.; Gavel, O. Y.; Di Rocco, G.; Lampreia, J.; Calvete, J.; Pereira, A. S.; Moura, J. J.; Moura, I. (J Inorg Biochem, 2004)
An orange-coloured protein (ORP) isolated from Desulfovibrio gigas, a sulphate reducer, has been previously shown by extended X-ray absorption fine structure (EXAFS) to contain a novel mixed-metal sulphide cluster of the type [S(2)MoS(2)CuS(2)MoS(2)] [J. Am. Chem. Soc. 122 (2000) 8321]. We report here the purification and the biochemical/spectroscopic characterisation of this novel protein. ORP is a soluble monomeric protein (11.8 kDa). The cluster is non-covalently bound to the polypeptide chain. The presence of a MoS(4)(2-) moiety in the structure of the cofactor contributes with a quite characteristic UV-Vis spectra, exhibiting an orange colour, with intense absorption peaks at 480 and 338 nm. Pure ORP reveals an Abs(480)/Abs(338) ratio of 0.535. The gene sequence coding for ORP as well as the amino acid sequence was determined. The putative biological function of ORP is discussed.
0162-0134 (Print)0162-0134 (Linking)Journal ArticleResearch Support, Non-U.S. Gov't
Keywords: Amino Acid Sequence; Bacterial Proteins/*chemistry/genetics/isolation & purification; Base Sequence; Cloning, Molecular; Copper/*chemistry; Desulfovibrio gigas/*chemistry/genetics; DNA, Bacterial/genetics; Metalloproteins/*chemistry/genetics/isolation & purification; Molecular Sequence Data; Molecular Structure; Molybdenum/*chemistry; Sequence Homology, Amino Acid; Spectrum Analysis

Crystallization and preliminary X-ray diffraction analysis of the 16-haem cytochrome of Desulfovibrio gigas - Santos-Silva, T.; Diasa, J. M.; Bourenkov, G.; Bartunik, H.; Moura, I.; Romao, M. J. (Acta Crystallographica Section D-Biological Crystallography, 2004)
High-molecular-weight cytochromes (Hmcs) belong to a large family of multihaem cytochromes in sulfate-reducing bacteria. HmcA is the first cytochrome reported to have 16 c-type haems arranged in its polypeptide chain. The function of this cytochrome is still unknown, although it is clear that it belongs to a membrane-bound complex involved in electron transfer from the periplasm to the membrane. HmcA from Desulfovibrio gigas has been purified and successfully crystallized using the hanging-drop vapour-diffusion method. The crystals grew using PEG and zinc acetate as precipitants to maximum dimensions of 0.2 x 0.2 x 0.2 mm in an orthorhombic space group, with unit-cell parameters a = 88.9, b = 90.9, c = 83.7 Angstrom. The crystals diffracted to beyond 2.07 Angstrom and a MAD data set was collected.
Times Cited: 2Part 5

Exploratory applications of diffusion ordered spectroscopy to liquid foods: an aid towards spectral assignment - Gil, A. M.; Duarte, I; E. Cabrita; Goodfellow, B. J.; Spraul, M; Kerssebaum, R (Analytica Chimica Acta, 2004)
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Incorporation of either molybdenum or tungsten into formate dehydrogenase from Desulfovibrio alaskensis NCIMB 13491; EPR assignment of the proximal iron-sulfur cluster to the pterin cofactor in formate dehydrogenases from sulfate-reducing bacteria - Brondino, C. D.; Passeggi, M. C.; Caldeira, J.; Almendra, M. J.; Feio, M. J.; Moura, J. J.; Moura, I. (J Biol Inorg Chem, 2004)
We report the characterization of the molecular properties and EPR studies of a new formate dehydrogenase (FDH) from the sulfate-reducing organism Desulfovibrio alaskensis NCIMB 13491. FDHs are enzymes that catalyze the two-electron oxidation of formate to carbon dioxide in several aerobic and anaerobic organisms. D. alaskensis FDH is a heterodimeric protein with a molecular weight of 126+/-2 kDa composed of two subunits, alpha=93+/-3 kDa and beta=32+/-2 kDa, which contains 6+/-1 Fe/molecule, 0.4+/-0.1 Mo/molecule, 0.3+/-0.1 W/molecule, and 1.3+/-0.1 guanine monophosphate nucleotides. The UV-vis absorption spectrum of D. alaskensis FDH is typical of an iron-sulfur protein with a broad band around 400 nm. Variable-temperature EPR studies performed on reduced samples of D. alaskensis FDH showed the presence of signals associated with the different paramagnetic centers of D. alaskensis FDH. Three rhombic signals having g-values and relaxation behavior characteristic of [4Fe-4S] clusters were observed in the 5-40 K temperature range. Two EPR signals with all the g-values less than two, which accounted for less than 0.1 spin/protein, typical of mononuclear Mo(V) and W(V), respectively, were observed. The signal associated with the W(V) ion has a larger deviation from the free electron g-value, as expected for tungsten in a d(1) configuration, albeit with an unusual relaxation behavior. The EPR parameters of the Mo(V) signal are within the range of values typically found for the slow-type signal observed in several Mo-containing proteins belonging to the xanthine oxidase family of enzymes. Mo(V) resonances are split at temperatures below 50 K by magnetic coupling with one of the Fe/S clusters. The analysis of the inter-center magnetic interaction allowed us to assign the EPR-distinguishable iron-sulfur clusters with those seen in the crystal structure of a homologous enzyme.
0949-8257 (Print)0949-8257 (Linking)Journal ArticleResearch Support, Non-U.S. Gov't
Keywords: Chromatography, Gel; Chromatography, High Pressure Liquid; Desulfovibrio/chemistry/*enzymology/growth & development; Electromagnetic Fields; Electron Spin Resonance Spectroscopy; Electrophoresis, Polyacrylamide Gel; Formate Dehydrogenases/chemistry/*metabolism; Iron/*chemistry; Molecular Weight; Molybdenum/*metabolism; Oxidation-Reduction; Pterins/*chemistry; Spectrophotometry, Ultraviolet; Sulfates/metabolism; Sulfur/*chemistry; Tungsten/*metabolism

Antagonists Mo and Cu in a heterometallic cluster present on a novel protein (orange protein) isolated from Desulfovibrio gigas - Bursakov, S. A.; Gavel, O. Y.; Di Rocco, G.; Lampreia, J.; Calvete, J.; Pereira, A. S.; Moura, J. J. G.; Moura, I. (Journal Of Inorganic Biochemistry, 2004)
An orange-coloured protein (ORP) isolated from Desulfovibrio gigas, a sulphate reducer, has been previously shown by extended X-ray absorption fine structure (EXAFS) to contain a novel mixed-metal sulphide cluster of the type [S2MoS2CuS2MoS2] [J. Am. Chem. Soc. 122 (2000) 8321]. We report here the purification and the biochemical/spectroscopic characterisation of this novel protein. ORP is a soluble monomeric protein (11.8 kDa). The cluster is non-covalently bound to the polypeptide chain. The presence of a MoS42- moiety in the structure of the cofactor contributes with a quite characteristic UV-Vis spectra, exhibiting an orange colour, with intense absorption peaks at 480 and 338 nm. Pure ORP reveals an Abs(480)/Abs(338) ratio of 0.535. The gene sequence coding for ORP as well as the amino acid sequence was determined. The putative biological function of ORP is discussed. (C) 2003 Elsevier Inc. All rights reserved.
11th International Conference on Biological Inorganic Chemistry, Cairns, AUSTRALIA, JUL 19-23, 2003

Copper-containing nitrite reductase from Pseudomonas chlororaphis DSM 50135 - Evidence for modulation of the rate of intramolecular electron transfer through nitrite binding to the type 2 copper center - Pinho, D.; Besson, S.; Brondino, C. D.; de Castro, B.; Moura, I. (European Journal of Biochemistry, 2004)
The nitrite reductase (Nir) isolated from Pseudomonas chlororaphis DSM 50135 is a blue enzyme, with type 1 and type 2 copper centers, as in all copper-containing Nirs described so far. For the first time, a direct determination of the reduction potentials of both copper centers in a Cu-Nir was performed: type 2 copper (T2Cu), 172 mV and type 1 copper (T1Cu), 298 mV at pH 7.6. Although the obtained values seem to be inconsistent with the established electron-transfer mechanism, EPR data indicate that the binding of nitrite to the T2Cu center increases its potential, favoring the electron-transfer process. Analysis of the EPR spectrum of the turnover form of the enzyme also suggests that the electron-transfer process between T1Cu and T2Cu is the fastest of the three redox processes involved in the catalysis: (a) reduction of T1Cu; (b) oxidation of T1Cu by T2Cu; and (c) reoxidation of T2Cu by NO2-. Electrochemical experiments show that azurin from the same organism can donate electrons to this enzyme.
Times Cited: 13

Discussão de temas de cenarização para a indústria automóvel para aplicação do método Delphi em Portugal [Discussion of scenario topics for the automotive industry to apply a Delphi method - António Moniz (University Library of Munich, Germany, 2004)
As was recently published in the GERPISA newsletter, one of the aims of the research for the new years will be the knowledge of interactions between the organisational company dynamics and the social-economical models of development. If one takes the example of the German exercise in the framework of FUTUR programme, one of the main thematic groups that emerged from the first discussions was preciselly “Mobility: individually atractive and socially sustainable”. Also the IMVP programme at MIT is taking these questions on the “visions for a sustainable future” theme. In the same way the WorTiS Project analysed several scenario topics on the issue of mobility and automotive industry. Those scenario topics are explained and justified in this research paper.
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Keywords: automotive industry; futures; mobility; scenario making; sustainable development

Structural basis for the mechanism of Ca2+ activation of the di-heme cytochrome c peroxidase from Pseudomonas nautica 617 - Dias, J. M.; Alves, T.; Bonifacio, C.; Pereira, A. S.; Trincao, J.; Bourgeois, D.; Moura, I.; Romao, M. J. (Structure, 2004)
Cytochrome c peroxidase (CCP) catalyses the reduction of H2O2 to H2O, an important step in the cellular detoxification process. The crystal structure of the di-heme CCP from Pseudomonas nautica 617 was obtained in two different conformations in a redox state with the electron transfer heme reduced. Form IN, obtained at pH 4.0, does not contain Ca2+ and was refined at 2.2 Angstrom resolution. This inactive form presents a closed conformation where the peroxidatic heme adopts a six-ligand coordination, hindering the peroxidatic reaction from taking place. Form OUT is Ca2+ dependent and was crystallized at pH 5.3 and refined at 2.4 Angstrom resolution. This active form shows an open conformation, with release of the distal histidine (His71) ligand, providing peroxide access to the active site. This is the first time that the active and inactive states are reported for a di-heme peroxidase.
Times Cited: 32

{Discussão de temas de cenarização para a indústria automóvel para aplicação do método Delphi em Portugal [Discussion of scenario topics for the automotive industry to apply a Delphi method in Portu} - António Moniz (University Library of Munich, Germany, 2004)
As was recently published in the GERPISA newsletter, one of the aims of the research for the new years will be the knowledge of interactions between the organisational company dynamics and the social-economical models of development. If one takes the example of the German exercise in the framework of FUTUR programme, one of the main thematic groups that emerged from the first discussions was preciselly “Mobility: individually atractive and socially sustainable”. Also the IMVP programme at MIT is taking these questions on the “visions for a sustainable future” theme. In the same way the WorTiS Project analysed several scenario topics on the issue of mobility and automotive industry. Those scenario topics are explained and justified in this research paper.
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Keywords: automotive industry; futures; mobility; scenario making; sustainable development

X-ray crystal structure and EPR spectra of "arsenite-inhibited" Desulfovibriogigas aldehyde dehydrogenase: a member of the xanthine oxidase family - Boer, D. R.; Thapper, A.; Brondino, C. D.; Romao, M. J.; Moura, J. J. (J Am Chem Soc, 2004)
X-ray crystallography has been used to determine the structure of arsenite-inhibited aldehyde dehydrogenase from Desulfovibrio gigas, a member of the xanthine oxidase family of mononuclear molybdenum enzymes. The structure shows an AsO3 moiety bound to the molybdenum atom of the active site through one of the oxygen atoms. A reduced sample of arsenite-inhibited aldehyde dehydrogenase has a Mo(V) signal that shows anisotropic hyperfine and quadrupole coupling to one arsenic atom. This signal has a strong resemblance with a previously reported signal for arsenite-inhibited xanthine oxidase.
0002-7863 (Print)0002-7863 (Linking)Journal ArticleResearch Support, Non-U.S. Gov't
Keywords: Aldehyde Oxidoreductases/*antagonists & inhibitors/*chemistry/metabolism; Arsenites/metabolism/*pharmacology; Crystallography, X-Ray; Desulfovibrio gigas/*enzymology; Electron Spin Resonance Spectroscopy/methods; Ligands; Molecular Structure; Molybdenum/chemistry; Oxidation-Reduction; Xanthine Oxidase/antagonists & inhibitors/*chemistry/metabolism

Structural stability of adenylate kinase from the sulfate-reducing bacteria Desulfovibrio gigas - Gavel, O. Y.; Bursakov, S. A.; Pina, D. G.; Zhadan, G. G.; Moura, J. J.; Moura, I.; Shnyrov, V. L. (Biophys Chem, 2004)
A novel adenylate kinase (AK) has recently been purified from Desulfovibrio gigas and characterized as a Co(2+)/Zn(2+)-containing enzyme: this is an unusual characteristic for AKs from Gram-negative bacteria, in which these enzymes are normally devoid of metals. Here, we studied the conformational stability of holo- and apo-AK as a function of temperature by differential scanning calorimetry (DSC), circular dichroism (CD), and intrinsic fluorescence spectroscopy. The thermal unfolding of AK is a cooperative two-state process, and is sufficiently reversible in the 9-11 pH range, that can be correctly interpreted in terms of a simple two-state thermodynamic model. The spectral parameters as monitored by ellipticity changes in the CD spectra of the enzyme as well as the decrease in tryptophan intensity emission upon heating were seen to be good complements to the highly sensitive but integral DSC-method.
0301-4622 (Print)0301-4622 (Linking)Journal ArticleResearch Support, Non-U.S. Gov't
Keywords: Adenylate Kinase/chemistry/isolation & purification/*metabolism; Calorimetry, Differential Scanning; Circular Dichroism; Desulfovibrio gigas/*enzymology; Enzyme Stability; Protein Conformation; Protein Denaturation; Spectrometry, Fluorescence; Sulfur-Reducing Bacteria/*enzymology; Thermodynamics; Tryptophan/chemistry

Structural basis for the mechanism of Ca2+ activation of the di-heme cytochrome c peroxidase from Pseudomonas nautica 617 - Dias, J. M.; Alves, T.; Bonifacio, C.; Pereira, A. S.; Trincao, J.; Bourgeois, D.; Moura, I.; Romão, M.J. (Structure, 2004)
Cytochrome c peroxidase (CCP) catalyses the reduction of H2O2 to H2O, an important step in the cellular detoxification process. The crystal structure of the di-heme CCP from Pseudomonas nautica 617 was obtained in two different conformations in a redox state with the electron transfer heme reduced. Form IN, obtained at pH 4.0, does not contain Ca2+ and was refined at 2.2 Angstrom resolution. This inactive form presents a closed conformation where the peroxidatic heme adopts a six-ligand coordination, hindering the peroxidatic reaction from taking place. Form OUT is Ca2+ dependent and was crystallized at pH 5.3 and refined at 2.4 Angstrom resolution. This active form shows an open conformation, with release of the distal histidine (His71) ligand, providing peroxide access to the active site. This is the first time that the active and inactive states are reported for a di-heme peroxidase.
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Two azurins with unusual redox and spectroscopic properties isolated from the Pseudomonas chlororaphis strains DSM 50083(T) and DSM 50135 - Pinho, D.; Besson, S.; Brondino, C. D.; Pereira, E.; de Castro, B.; Moura, I. (Journal of Inorganic Biochemistry, 2004)
Two azurins (Az624 and Az626) were isolated from the soluble extract of two strains of Pseudomonas chlororaphis, DSM 50083(T) and DSM 50135, respectively, grown under microaerobic conditions with nitrate as final electron acceptor. The azurins, purified to electrophoretic homogeneity in three chromatographic steps, exhibit several peculiar properties. They have high reduction potentials and lower pI than most azurins described in the literature. As previously observed for Pseudomonas aeruginosa azurin, their reduction potentials are pH-dependent, but the pK values of their oxidized forms are lower, which suggests that deeper structural changes are associated with the oxidation process of these novel azurins. A hitherto undescribed pH-dependence of the diffusion coefficient was observed in Az624, that could be caused either by conformational changes, or by the formation of supramolecular aggregates associated with a protonation process. Both azurins exhibit axial X-band electron paramagnetic resonance spectra in frozen solution showing a typical hyperfine with the copper nucleus (I = 3/2) and a well-resolved superhyperfine structure with two equivalent N-14 nucleus (I = 1), which is not usually observed for azurins from other species. (C) 2003 Elsevier Inc. All rights reserved.
Times Cited: 4

A Fractional Linear System View of the Fractional Brownian Motion - Ortigueira, M.D.; Batista, A.G. (Nonlinear Dynamics, 2004)
A definition of the fractional Brownian motion based on the fractional differintegrator characteristics is proposed and studied. It is shown that the model enjoys the usually required properties. A discrete-time version based in the backward difference and in the bilinear transformation is considered. Some results are presented.
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Ligand K-edge X-ray absorption spectroscopy and DFT calculations on [Fe3S4]0,+ clusters: delocalization, redox, and effect of the protein environment - Dey, A.; Glaser, T.; Moura, J. J.; Holm, R. H.; Hedman, B.; Hodgson, K. O.; Solomon, E. I. (J Am Chem Soc, 2004)
Ligand K-edge XAS of an [Fe3S4]0 model complex is reported. The pre-edge can be resolved into contributions from the mu(2)S(sulfide), mu(3)S(sulfide), and S(thiolate) ligands. The average ligand-metal bond covalencies obtained from these pre-edges are further distributed between Fe(3+) and Fe(2.5+) components using DFT calculations. The bridging ligand covalency in the [Fe2S2]+ subsite of the [Fe3S4]0 cluster is found to be significantly lower than its value in a reduced [Fe2S2] cluster (38% vs 61%, respectively). This lowered bridging ligand covalency reduces the superexchange coupling parameter J relative to its value in a reduced [Fe2S2]+ site (-146 cm(-1) vs -360 cm(-1), respectively). This decrease in J, along with estimates of the double exchange parameter B and vibronic coupling parameter lambda2/k(-), leads to an S = 2 delocalized ground state in the [Fe3S4]0 cluster. The S K-edge XAS of the protein ferredoxin II (Fd II) from the D. gigas active site shows a decrease in covalency compared to the model complex, in the same oxidation state, which correlates with the number of H-bonding interactions to specific sulfur ligands present in the active site. The changes in ligand-metal bond covalencies upon redox compared with DFT calculations indicate that the redox reaction involves a two-electron change (one-electron ionization plus a spin change of a second electron) with significant electronic relaxation. The presence of the redox inactive Fe(3+) center is found to decrease the barrier of the redox process in the [Fe3S4] cluster due to its strong antiferromagnetic coupling with the redox active Fe2S2 subsite.
0002-7863 (Print)0002-7863 (Linking)Journal ArticleResearch Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.
Keywords: Binding Sites; Ferredoxins/chemistry; Iron-Sulfur Proteins/*chemistry; Iron/chemistry; Models, Chemical; Models, Molecular; Oxidation-Reduction; Spectrometry, X-Ray Emission; Sulfur/chemistry; Thermodynamics

Direct electrochemistry of the Desulfovibrio gigas aldehyde oxidoreductase - Correia dos Santos, M. M.; Sousa, P. M.; Goncalves, M. L.; Romao, M. J.; Moura, I.; Moura, J. J. (Eur J Biochem, 2004)
This work reports on the direct electrochemistry of the Desulfovibrio gigas aldehyde oxidoreductase (DgAOR), a molybdenum enzyme of the xanthine oxidase family that contains three redox-active cofactors: two [2Fe-2S] centers and a molybdopterin cytosine dinucleotide cofactor. The voltammetric behavior of the enzyme was analyzed at gold and carbon (pyrolytic graphite and glassy carbon) electrodes. Two different strategies were used: one with the molecules confined to the electrode surface and a second with DgAOR in solution. In all of the cases studied, electron transfer took place, although different redox reactions were responsible for the voltammetric signal. From a thorough analysis of the voltammetric responses and the structural properties of the molecular surface of DgAOR, the redox reaction at the carbon electrodes could be assigned to the reduction of the more exposed iron cluster, [2Fe-2S] II, whereas reduction of the molybdopterin cofactor occurs at the gold electrode. Voltammetric results in the presence of aldehydes are also reported and discussed.
0014-2956 (Print)0014-2956 (Linking)Journal ArticleResearch Support, Non-U.S. Gov't
Keywords: Aldehyde Oxidoreductases/*chemistry; Aldehydes; Benzaldehydes/chemistry; Carbon/chemistry; Catalysis; Desulfovibrio gigas/*enzymology; Electrochemistry/*methods; Electron Transport; Gold; Models, Molecular; Oxidation-Reduction; Static Electricity

An efficient poly(pyrrole-viologen)-nitrite reductase biosensor for the mediated detection of nitrite - Da Silva, S.; Cosnier, S.; Almeida, M. G.; Moura, J. J. G. (Electrochemistry Communications, 2004)
A biosensor for nitrite analytical determination was developed using a cytochrome c nitrite reductase (ccNiR) from Desulfovibrio desufuricans ATCC 27774 immobilized and electrically connected on a glassy carbon electrode by entrapment in an electrogencrated poly(pyrrole-viologen) matrix. The modified bioelectrode was studied by cyclic voltammetry and a catalytic current was observed in presence of nitrite. The linear range of the electrode response was 5.4-43.4 muM. The detection limit and the sensitivity were 5.4 muM and 1721 mA M-1 cm(-2), respectively. The K-M(app) value determined from the Lineweaver-Burk plot was 86 muM. The biosensor fully maintained its electroenzymatic activity towards nitrite after four days.. No catalytic response was observed in the presence of nitrate ions while interference from sulfites was considered negligible. Finally, the biosensor composition was optimized in term of monomer-enzyme ratio. (C) 2004 Elsevier B.V. All rights reserved.
Times Cited: 13

A fluorescent chemosensor for Zn(II). Exciplex formation in solution and the solid state - Bencini, A; Berni, E; Bianchi, A; Fornasari, P; Giorgi, C; J. C. Lima; Lodeiro, C.; Melo, MJ; de Melo, JS; A. J. Parola; Pina, F; Pina, J; et al. (Dalton Transactions, 2004)
The macrocyclic phenanthrolinophane 2,9-[2,5,8-triaza-5-(N-anthracene-9-methylamino) ethyl]-[9]-1,10-henanthrolinophane(L) bearing a pendant arm containing a coordinating amine and an anthracene group forms stable complexes with Zn(II), Cd(II) and Hg(II) in solution. Stability constants of these complexes were determined in 0.10 mol dm(-3) NMe4Cl H2O-MeCN (1:1, v/v) solution at 298.1+/-0.1 K by means of potentiometric (pH metric) titration. The fluorescence emission properties of these complexes were studied in this solvent. For the Zn(II) complex, steady-state and time-resolved fluorescence studies were performed in ethanol solution and in the solid state. In solution, intramolecular pi-stacking interaction between phenanthroline and anthracene in the ground state and exciplex emission in the excited state were observed. From the temperature dependence of the photostationary ratio (I-Exc/I-M), the activation energy for the exciplex formation (E-a) and the binding energy of the exciplex (-DeltaH) were determined. The crystal structure of the [ZnLBr](ClO4).H2O compound was resolved, showing that in the solid state both intra- and inter-molecular pi-stacking interactions are present. Such interactions were also evidenced by UV-vis absorption and emission spectra in the solid state. The absorption spectrum of a thin film of the solid complex is red-shifted compared with the solution spectra, whereas its emission spectrum reveals the unique featureless exciplex band, blue shifted compared with the solution. In conjunction with X-ray data the solid-state data was interpreted as being due to a new exciplex where no pi-stacking (full overlap of the pi-electron cloud of the two chromophores-anthracene and phenanthroline) is observed. L is a fluorescent chemosensor able to signal Zn(II) in presence of Cd(II) and Hg(II), since the last two metal ions do not give rise either to the formation of pi-stacking complexes or to exciplex emission in solution.
ISI Document Delivery No.: 837GOTimes Cited: 30 Cited Reference Count: 59 Bencini, A Berni, E Bianchi, A Fornasari, P Giorgi, C Lima, JC Lodeiro, C Melo, MJ de Melo, JS Parola, AJ Pina, F Pina, J Valtancoli, B Melo, Maria Joao/C-8594-2011; Pina, Fernando/C-8161-2011; Seixas de Melo, Sergio/A-5388-2008; Lodeiro, Carlos/B-4793-2013; Parola, A. Jorge/F-4048-2010; Pina, Joao /H-9948-2013; Lima, Joao/F-3658-2010 Seixas de Melo, Sergio/0000-0001-9708-5079; Lodeiro, Carlos/0000-0001-5582-5446; Parola, A. Jorge/0000-0002-1333-9076; Lima, Joao/0000-0003-0528-1967 Royal soc chemistry Cambridge

Fluorescent type II materials from naphthylmethyl polyamine precursors - Alarcon, J.; Aucejo, R; Albelda, MT; Alves, S; Clares, MP; Garcia-Espana, E; Lodeiro, C.; Marchin, K. L.; A. J. Parola; Pina, F; de Melo, JS; Soriano, C (Supramolecular Chemistry, 2004)
Speciation studies in aqueous solution on the interaction Of Cu2+ and Zn2+ with a series of polyaminic ligands N-naphthalen-1-ylmethyl-N'-[2-[(naphthalen-1-ylmethyl)- amino]-ethyl)-ethane-l,2-diamine (LI), N-naphthalen-lylmethyl-iV-(2-{2-[(naphthalen-1-ylmethyl)-amino]-ethyl- amino]-ethyl)-ethane-l,2-diamine (L2) and N-naphthalen-1-ylmethyl-N'-[2-(2-{2-[(naphthalen-1-ylmethyl)-amino]- ethylamino)-ethylamino)-ethyl]-ethane-1,2-diamine (L3) containing two naphthylmethyl groups at their termini and N-1-(2-{2-[(naphthalen-1-ylmethyl)-amino]-ethyl-amino)-ethyl)-ethane-1,2-diamine (L4) containing just one naphthylmethyl group have been carried out at 298.1 K in 0.15 mol dm (-3) NaCl. In the case of the tetraamines L2 and L4, their coordination capabilities towards Cd2+, Ni2+, Co2+ and Pb2+ have also been considered. The stability constants follow the general Irving-Williams sequence. The steady-state fluorescence emission studies on the interaction with metal ions show that while Cu2+ produces a chelation enhancement of the quenching (CHEQ), the interaction with Zn2+ leads to a chelation enhancement of the fluorescence (CHEF). Finally, ligands L1, L2 and L3 have been successfully covalently attached to silica surfaces and some preliminary results of their emissive properties are given.
ISI Document Delivery No.: 885EGTimes Cited: 5 Cited Reference Count: 45 Alarcon, J Aucejo, R Albelda, MT Alves, S Clares, MP Garcia-Espana, E Lodeiro, C Marchin, KL Parola, AJ Pina, F De Melo, JS Soriano, C Seixas de Melo, Sergio/A-5388-2008; Pina, Fernando/C-8161-2011; Albelda, M. Teresa/J-5929-2012; Lodeiro, Carlos/B-4793-2013; Parola, A. Jorge/F-4048-2010; REQUIMTE, AL/H-9106-2013 Seixas de Melo, Sergio/0000-0001-9708-5079; Lodeiro, Carlos/0000-0001-5582-5446; Parola, A. Jorge/0000-0002-1333-9076; Taylor & francis ltd Abingdon

Multistate properties of 7-(N,N-diethylamino)-4 '-hydroxyflavylium. An example of an unidirectional reaction cycle driven by pH - Moncada, MC; Fernandez, D; J. C. Lima; A. J. Parola; Lodeiro, C.; Folgosa, F.; Melo, MJ; Pina, F (Organic & Biomolecular Chemistry, 2004)
The synthetic flavylium salt 7-(N,N-diethylamino)-4'-hydroxyflavylium tetrafluoroborate gives rise in aqueous solution to a complex network of chemical reactions driven by pH. The system was studied by H-1 NMR, single crystal X-ray diffraction, steady state and transient UV-Vis spectrophotometry as well as stopped flow. The crystal structure shows a high degree of coplanarity between the pyrylium system and the phenyl group in position 2. Thermodynamic and kinetic constants for the pH dependent network of chemical reactions were obtained. The introduction of an amino group in position 7 allows formation of protonated species leading, in particular, to a tautomeric form of the protonated cis-chalcone, CcH(+), whose absorption spectra is rather red shifted, in comparison with the correspondent protonated trans-chalcone, CtH(+). The CcH(+) species can be rapidly converted into the flavylium cation through a first order process with lifetime of 0.2 s at pH = 2.35. This new reaction channel confers this compound a peculiar behaviour in acidic media, allowing to define an unidirectional pH driven reaction cycle.
ISI Document Delivery No.: 858EUTimes Cited: 16 Cited Reference Count: 37 Moncada, MC Fernandez, D Lima, JC Parola, AJ Lodeiro, C Folgosa, F Melo, MJ Pina, F Melo, Maria Joao/C-8594-2011; Pina, Fernando/C-8161-2011; Folgosa, Filipe/F-7640-2012; Lodeiro, Carlos/B-4793-2013; Parola, A. Jorge/F-4048-2010; REQUIMTE, AL/H-9106-2013; Lima, Joao/F-3658-2010 Folgosa, Filipe/0000-0001-5879-151X; Lodeiro, Carlos/0000-0001-5582-5446; Parola, A. Jorge/0000-0002-1333-9076; Lima, Joao/0000-0003-0528-1967 Royal soc chemistry Cambridge

Multistate/multifunctional behaviour of 4 '-hydroxy-6-nitroflavylium: A write-lock/read/unlock/enable-erase/erase cycle driven by light and pH stimulation - Moncada, MC; A. J. Parola; Lodeiro, C.; Pina, F; Maestri, M; Balzani, V. (Chemistry-a European Journal, 2004)
We have investigated the network of reactions observed for the photochromic 4'-hydroxy-6-nitroflavylium compound in aqueous solutions upon pH changes (including pH jump and stopped flow experiments) and light excitation. The changes observed in the NMR and UV/Vis spectra allowed identification of ten different forms in which this compound can be transformed depending on the experimental conditions. Equilibrium and kinetic constants have been determined. Compared with other members of the flavylium family, 4'-hydroxy-6-nitroflavylium is characterized by a large cis --> trans isomerization barrier, and a very efficient hydration reaction. These peculiar features allow writing, reading, storing and erasing photonic information on 4'-hydroxy-6-nitroflavylium by a novel cyclic process that involves the following steps: write-lock/read/unlock/enable-erase/erase.
ISI Document Delivery No.: 807ECTimes Cited: 13 Cited Reference Count: 32 Moncada, MC Parola, AJ Lodeiro, C Pina, F Maestri, M Balzani, V Pina, Fernando/C-8161-2011; Lodeiro, Carlos/B-4793-2013; Parola, A. Jorge/F-4048-2010; REQUIMTE, AL/H-9106-2013 Lodeiro, Carlos/0000-0001-5582-5446; Parola, A. Jorge/0000-0002-1333-9076; Wiley-v c h verlag gmbh Weinheim

Protonation and coordination properties towards Zn(II), Cd(II) and Hg(II) of a phenanthroline-containing macrocycle with an ethylamino pendant arm - Bazzicalupi, C; Bencini, A; Berni, E; Bianchi, A; Borsari, L; Giorgi, C; Valtancoli, B; Lodeiro, C.; J. C. Lima; A. J. Parola; Pina, F (Dalton Transactions, 2004)
Protonation and Zn(II), Cd(II) and Hg(II) coordination with the ligand 5-aminoethyl-2,5,8-triaza-[9]-10,23-phenanthrolinophane (L2), which contains an aminoethyl pendant attached to a phenanthroline-containing macrocycle, have been investigated by means of potentiometric, H-1 NMR and spectrofluorimetric titrations in aqueous solutions. The coordination properties of L2 are compared with those of the ligand 2,5,8-triaza-[9]-10,23-phenanthrolinophane (L1). Ligand protonation occurs on the aliphatic amine groups and does not involve directly the heteroaromatic nitrogens. The fluorescence emission properties of L2 are controlled by the protonation state of the benzylic nitrogens: when not protonated, their lone pairs are available for an electron transfer process to the excited phenanthroline, quenching the emission. As a consequence, the ligand is emissive only in the highly charged [H(3)L2](3+) and [H(4)L2](4+) species, where the benzylic nitrogens are protonated. Considering metal complexation, both [ML1](2+) and [ML2](2+) complexes (M=Zn(II) and Cd(II)) are not emissive, since the benzylic nitrogens are weakly involved in metal coordination, and, once again, they are available for quenching the fluorescence emission. Protonation of the L2 complexes to give [MHL2](3+) species, instead, leads to a recovery of the fluorescence emission. Complex protonation, in fact, occurs on the ethylamino group and gives a marked change of the coordination sphere of the metals, with a stronger involvement in metal coordination of the benzylic nitrogens; consequently, their lone pairs are not available for the process of emission quenching.
ISI Document Delivery No.: 772KWTimes Cited: 24 Cited Reference Count: 110 Bazzicalupi, C Bencini, A Berni, E Bianchi, A Borsari, L Giorgi, C Valtancoli, B Lodeiro, C Lima, JC Parola, AJ Pina, F Pina, Fernando/C-8161-2011; Lodeiro, Carlos/B-4793-2013; Parola, A. Jorge/F-4048-2010; REQUIMTE, AL/H-9106-2013; Lima, Joao/F-3658-2010 Lodeiro, Carlos/0000-0001-5582-5446; Parola, A. Jorge/0000-0002-1333-9076; Lima, Joao/0000-0003-0528-1967 Royal soc chemistry Cambridge

Synthesis and H+, Cu2+, and Zn2+ coordination behavior of a bis(fluorophoric) bibrachial lariat aza-crown - Clares, MP; Aguilar, J; Aucejo, R; Lodeiro, C.; Albelda, MT; Pina, F; J. C. Lima; A. J. Parola; Pina, J; de Melo, JS; Soriano, C; Garcia-Espana, E (Inorganic Chemistry, 2004)
The synthesis, protonation behavior, and Cu2+ and Zn2+ coordination chemistry of the novel bibrachial aza lariat ether (naphthalen-1-ylmethyl)[2-(20-{2-[(naphthalen-1-ylmethyl)amino]ethyl}-3,6,9,17,20,23,29,30-octaazatricyclo-[23.3.1.1*11,15*]triaconta-1(29),11(30),12,14,25,27-hexaen-6-yl)ethyl]amine (L) are discussed. The macrocycle, which has two aminoethyl naphthyl moieties symmetrically appended to a 2:2 azapyridinophane structure, displays, in the pH range 2-11, six protonation steps that correspond to the protonation of the secondary amino groups. Steady-state fluorescence measurements show emissions due to the monomer and to the excimer formed between the two naphthalene fragments of the macrocycle. The time-resolved fluorescence data, obtained by the time-correlated single photon counting technique, show that a significant percentage of excimer is preformed as ground-state dimers. The ligand L forms with the metal ions Cu2+ and Zn2+ mono- and dinuclear complexes in aqueous solution. The influence of metal coordination in the fluorescence emission of L is analyzed. The acid-base, coordination capabilities, and emissive behavior of L are compared with those presented by its synthetic precursor L1, which has a tripodal tris(2-aminoethyl)amine structure functionalized at one of its terminal amino groups with a naphthyl moiety.
ISI Document Delivery No.: 854VGTimes Cited: 37 Cited Reference Count: 65 Clares, MP Aguilar, J Aucejo, R Lodeiro, C Albelda, MT Pina, F Lima, JC Parola, AJ Pina, J de Melo, JS Soriano, C Garcia-Espana, E Seixas de Melo, Sergio/A-5388-2008; Pina, Fernando/C-8161-2011; Albelda, M. Teresa/J-5929-2012; Lodeiro, Carlos/B-4793-2013; Parola, A. Jorge/F-4048-2010; REQUIMTE, AL/H-9106-2013; Pina, Joao /H-9948-2013; Lima, Joao/F-3658-2010 Seixas de Melo, Sergio/0000-0001-9708-5079; Lodeiro, Carlos/0000-0001-5582-5446; Parola, A. Jorge/0000-0002-1333-9076; Lima, Joao/0000-0003-0528-1967 Amer chemical soc Washington

Thermal and photochemical properties of 4 ',7-dihydroxyflavylium in water-ionic liquid biphasic systems: A write-read-erase molecular switch - Pina, F; J. C. Lima; A. J. Parola; C. A. M. Afonso (Angewandte Chemie-International Edition, 2004)
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ISI Document Delivery No.: 805TWTimes Cited: 51 Cited Reference Count: 33 Pina, F Lima, JC Parola, AJ Afonso, CAM Pina, Fernando/C-8161-2011; Parola, A. Jorge/F-4048-2010; REQUIMTE, AL/H-9106-2013; Lima, Joao/F-3658-2010 Parola, A. Jorge/0000-0002-1333-9076; Lima, Joao/0000-0003-0528-1967 Wiley-v c h verlag gmbh Weinheim

Thermal and photochemical properties of 4 '-hydroxyflavylium in water-ionic liquid biphasic systems - Fernandez, D; A. J. Parola; Branco, L. C.; C. A. M. Afonso; Pina, F (Journal of Photochemistry and Photobiology a-Chemistry, 2004)
The multistate/multifunctional properties of 4'-hydroxyflavylium in a water/ I -n-butyl-3 -methyl-imidazolium hexalluorophosphate (fbmim][PF6]) biphasic system are described. The kinetics and thermodynamics of this flavylium salt have been fully characterised in aqueous solutions and compared to those obtained in [bmim][PF6]. The trans-chalcone is thermally more stable in the ionic liquid but shows efficient photoisomerisation to the cis-chalcone, allowing to define write-read-erase cycles in this biphasic system. (C) 2004 Elsevier B.V. All rights reserved.
ISI Document Delivery No.: 871GOTimes Cited: 11 Cited Reference Count: 29 Fernandez, D Parola, AJ Branco, LC Afonso, CAM Pina, F Pina, Fernando/C-8161-2011; Parola, A. Jorge/F-4048-2010; Branco, Luis/C-6426-2013; REQUIMTE, AL/H-9106-2013 Parola, A. Jorge/0000-0002-1333-9076; Branco, Luis/0000-0003-2520-1151; Elsevier science sa Lausanne

Tuning the photochromic properties of a flavylium compound by pH - Moncada, MC; Pina, F; Roque, A.; A. J. Parola; Maestri, M; Balzani, V. (European Journal of Organic Chemistry, 2004)
We studied the intricate pH- and light-dependent network of the thermal and photochemical reactions of the 4'-(dimethylamino) -7-hydroxyflavylium ion by continuous irradiation, flash photolysis, H-1 NMR spectroscopy, and stopped flow analysis. The distribution of the various forms at the pH-dependent thermodynamic equilibrium and the rates of several interconversion processes were measured. The most interesting feature of this multistate/multifunctional system is related to the possibility of pH-tuning the colour change caused by photoirradiation, because the cis-chalcone isomer, obtained from the photoisomerization of the trans-chalcone form, is spontaneously transformed into coloured species (flavylium. cation and quinoidal base) at low values of pH, but reverts back to the uncoloured trans-chalcone at high values of pH because of the low energy barrier between the cis and trans chalcone isomers. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).
ISI Document Delivery No.: 768EXTimes Cited: 13 Cited Reference Count: 28 Moncada, MC Pina, F Roque, A Parola, AJ Maestri, M Balzani, V Pina, Fernando/C-8161-2011; Parola, A. Jorge/F-4048-2010; REQUIMTE, AL/H-9106-2013 Parola, A. Jorge/0000-0002-1333-9076; Wiley-v c h verlag gmbh Weinheim

Two coupled photochromic systems of 3 ',4 '-(methylenedioxy)flavylium: kinetic and thermodynamic characterization - Fernandez, D; Folgosa, F.; A. J. Parola; Pina, F (New Journal of Chemistry, 2004)
The chemistry and photochemistry of 3',4'-(methylenedioxy)flavylium was studied by means of UV-Vis spectrophotometry, H-1 NMR, stopped flow, and continuous irradiation, in acidic and basic aqueous solutions. Six species were identified: the flavylium cation, AH(+); the hemiketal, B; the cis- and the trans-chalcones, Cc and Ct, and their ionized forms, Cc(-) and Ct(-). These species de. ne a multiequilibria network whose kinetics and thermodynamics were completely characterized. The two pairs of chalcones de. ne two coupled photochromic systems, respectively in acidic and basic media, both allowing cycles capable of writing, reading and erasing to be defined.
ISI Document Delivery No.: 859MPTimes Cited: 3 Cited Reference Count: 11 Fernandez, D Folgosa, F Parola, AJ Pina, F Pina, Fernando/C-8161-2011; Folgosa, Filipe/F-7640-2012; Parola, A. Jorge/F-4048-2010; REQUIMTE, AL/H-9106-2013 Folgosa, Filipe/0000-0001-5879-151X; Parola, A. Jorge/0000-0002-1333-9076; Royal soc chemistry Cambridge

Purification, characterization and functional analysis of an endo-arabinanase (AbnA) from Bacillus subtilis. - Leal, Teresa Fontes; Isabel de Sá-Nogueira (FEMS Microbiology Letters, 2004)
Bacillus subtilis synthesizes at least one arabinanase encoded by the abnA gene that is able to degrade the polysaccharide arabinan. Here, we report the expression in Escherichia coli of the full-length abnA coding region with a His6-tag fused to the C-terminus. The recombinant protein was secreted to the periplasmic space and correctly processed by the E. coli signal peptidase. The substrate specificity of purified AbnA, the physico-chemical properties and kinetic parameters were determined. Functional analysis studies revealed Glu 215 as a key residue for AbnA hydrolytic activity and indicated that in addition to AbnA B. subtilis secretes other enzyme(s) able to degrade linear 1,5-α-L-arabinan.
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A combined approach to fault diagnosis in dynamic systems - Palma, L. B.; Coito, F.; Neves-Silva, R. (2004)
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List of Selected Specific Indicators and Its Evolution Deliverable 9 – ECOPADEV - Amado, Miguel (European Comission, 2004)

Molecular mobility and fragility in n-ethylene glycol dimethacrylate monomers - M. T. Viciosa; M. Dionísio (Journal of Non-Crystalline Solids, 2004)

O Processo do Planeamento Urbano Sustentável - Amado, Miguel (Faculdade de Ciências e Tecnologia, 2004)

Patologias na cobertura do Edifício do Centro Comercial FORUM – Avenida Alfredo da Silva no Barreiro - Amado, Miguel (2004)

Recombination and chromosome segregation - D. J. Sherratt; B. Soballe; F. -X. Barre; S. R. Filipe; T. Massey; I. Lau; J. Yates (Phil. Trans. R. Soc. Lond. B, 2004)

Redox behaviour of the haem domain of flavocytochrome c3 from Shewanella frigidimarina probed by NMR - Miguel Pessanha; Emma L. Rothery; Ricardo O. Louro; Turner, David L.; Caroline S. Miles; Graeme A. Reid; Stephen K. Chapman; Xavier, António V.; Salgueiro, C.A. (FEBS Letters, 2004)
Flavocytochrome c3 from Shewanella frigidimarina (fcc3) is a tetrahaem periplasmic protein of 64 kDa with fumarate reductase activity. This work reports the first example of NMR techniques applied to the assignment of the thermodynamic order of oxidation of the four individual haems for such large protein, expanding its applicability to a wide range of proteins. NMR data from partially and fully oxidised samples of fcc3 and a mutated protein with an axial ligand of haem IV replaced by alanine were compared with calculated chemical shifts, allowing the structural assignment of the signals and the unequivocal determination of the order of oxidation of the haems. As oxidation progresses the fcc3 haem domain is polarised, with haems I and II much more oxidised than haems III and IV, haem IV being the most reduced. Thus, during catalysis as an electron is taken by the flavin adenosine dinucleotide from haem IV, haem III is eager to re-reduce haem IV, allowing the transfer of two electrons to the active site.

Redox Characterization of Geobacter sulfurreducens Cytochrome c7: Physiological Relevance of the Conserved Residue F15 Probed by Site-Specific Mutagenesis - Miguel Pessanha; Londer, Yuri Y.; Long, W.C.; Erickson, Jill; Pokkuluri, P.R.; Schiffer, Marianne; Salgueiro, C.A. (Biochemistry, 2004)
The complete genome sequence of the δ-proteobacterium Geobacter sulfurreducens reveals a large abundance of multiheme cytochromes. Cytochrome c7, isolated from this metal ion-reducing bacterium, is a triheme periplasmic electron-transfer protein with Mr 9.6 kDa. This protein is involved in metal ion-reducing pathways and shares 56% sequence identity with a triheme cytochrome isolated from the closely related δ-proteobacterium Desulfuromonas acetoxidans (Dac7). In this work, two-dimensional NMR was used to monitor the heme core and the general folding in solution of the G. sulfurreducens triheme cytochrome c7 (PpcA). NMR signals obtained for the three hemes of PpcA at different stages of oxidation were cross-assigned to the crystal structure [Pokkuluri, P. R., Londer, Y. Y., Duke, N. E. C., Long, W. C., and Schiffer, M. (2004) Biochemistry 43, 849−859] using the complete network of chemical exchange connectivities, and the order in which each heme becomes oxidized was determined at pH 6.0 and 8.2. Redox titrations followed by visible spectroscopy were also performed in order to monitor the macroscopic redox behavior of PpcA. The results obtained showed that PpcA and Dac7 have different redox properties:  (i) the order in which each heme becomes oxidized is different; (ii) the reduction potentials of the heme groups and the global redox behavior of PpcA are pH dependent (redox−Bohr effect) in the physiological pH range, which is not observed with Dac7. The differences observed in the redox behavior of PpcA and Dac7 may account for the different functions of these proteins and constitute an excellent example of how homologous proteins can perform different physiological functions. The redox titrations followed by visible spectroscopy of PpcA and two mutants of the conserved residue F15 (PpcAF15Y and PpcAF15W) lead to the conclusion that F15 modulates the redox behavior of PpcA, thus having an important physiological role.

Regioselective Copolymerisation of Acryl Sucrose Monomers - M. T. Barros; K. T. Petrova; A. M. Ramos (J. Org. Chem., 2004)

Relatório de candidatura à Concessão de Terras no Cacuaco, Luanda - Amado, Miguel; Others (GEOTPU, 2004)

The role of murE in the expression of b-lactam antibiotic resistance in Staphylococcus aureus - S. Gardete; A. M. Ludovice; Sobral, R. G.; S. R. Filipe; H. de Lencastre; A. Tomasz (J. Bacteriol, 2004)

Structure of a novel c7-type three-heme cytochrome domain from a multidomain cytochrome c polymer - Pokkuluri, P.R.; Londer, Yuri Y.; Norma E.C. Duke; Erickson, Jill; Miguel Pessanha; Salgueiro, C.A.; Schiffer, Marianne (Protein Science, 2004)
The structure of a novel c7-type cytochrome domain that has two bishistidine coordinated hemes and one heme with histidine, methionine coordination (where the sixth ligand is a methionine residue) was determined at 1.7 Å resolution. This domain is a representative of domains that form three polymers encoded by the Geobacter sulfurreducens genome. Two of these polymers consist of four and one protein of nine c7-type domains with a total of 12 and 27 hemes, respectively. Four individual domains (termed A, B, C, and D) from one such multiheme cytochrome c (ORF03300) were cloned and expressed in Escherichia coli. The domain C produced diffraction quality crystals from 2.4 M sodium malonate (pH 7). The structure was solved by MAD method and refined to an R-factor of 19.5% and R-free of 21.8%. Unlike the two c7 molecules with known structures, one from G. sulfurreducens (PpcA) and one from Desulfuromonas acetoxidans where all three hemes are bishistidine coordinated, this domain contains a heme which is coordinated by a methionine and a histidine residue. As a result, the corresponding heme could have a higher potential than the other two hemes. The apparent midpoint reduction potential, Eapp, of domain C is −105 mV, 50 mV higher than that of PpcA.

Tensile properties of cellulose fiber reinforced hydroxypropylcellulose films - Borges, João Paulo; Godinho, Maria Helena; Martins, Assis Farinha; Stamatialis, DF; de Pinho, MN; Belgacem, Mohamed Naceur (Polymer composites, 2004)
The tensile properties of cross-linked and uncross-linked composite films (thickness ∼20–35 μm) prepared from Hydroxypropylcellulose (HPC) with incorporation of microcrystalline cellulose fibers (Avicel) were studied. The concentration of fibers in the composites ranged from 0 to 30 w/w% and cross-linked composites were obtained by the reaction of HPC-Avicel mixtures with 1,4-butyldiisocyanate. It was demonstrated that the inclusion of fibers in a HPC matrix produces composites with enhanced mechanical properties that are improved by cross-linking. Mechanical results seem to indicate that the elastic deformation of the cross-linked composites is predominantly dominated by the fiber content while the cross-linking affects mainly the plastic deformation. Maximum values of the Young's Modulus, yield stress and tensile stress were observed at 10 w/w% for the cross-linked and 20 w/w% for the uncross-linked composites. Furthermore cross-linked films with 10 w/w% of fibers present values of yield stress and tensile stress that are in average 15 to 20% higher than those obtained for uncross-linked composites with 20 w/w% of fibers. Studies in Polarizing Optical Microscopy and Atomic Force Microscopy (AFM) seem to indicate that tensile properties of these composites are correlated to the packing of fibers. For the concentration of the utilized cross-linking agent, and for a fiber content of 10 w/w%, an optimal packing of fibers throughout the matrix has been correlated to the minimal difference between the roughness parameters obtained by AFM analysis of the top and bottom surfaces of the films.

Transcriptional Regulation of Genes Encoding Arabinan-Degrading Enzymes in Bacillus subtilis - Raposo, Maria Paiva; Inácio, José Manuel; Mota, Luís Jaime; Isabel de Sá-Nogueira (Journal of Bacteriology, 2004)
Bacillus subtilis produces hemicellulases capable of releasing arabinosyl oligomers and arabinose from plant cell walls. In this work, we characterize the transcriptional regulation of three genes encoding arabinan-degrading enzymes that are clustered with genes encoding enzymes that further catabolize arabinose. The abfA gene comprised in the metabolic operon araABDLMNPQ-abfA and the xsa gene located 23 kb downstream most probably encode α-L-arabinofuranosidases (EC 3.2.1.55). Here, we show that the abnA gene, positioned immediately upstream from the metabolic operon, encodes an endo-α-1,5-arabinanase (EC 3.2.1.99). Furthermore, by in vivo RNA studies, we inferred that abnA and xsa are monocistronic and are transcribed from σA-like promoters. Transcriptional fusion analysis revealed that the expression of the three arabinases is induced by arabinose and arabinan and is repressed by glucose. The levels of induction by arabinose and arabinan are higher during early postexponential growth, suggesting a temporal regulation. Moreover, the induction mechanism of these genes is mediated through negative control by the key regulator of arabinose metabolism, AraR. Thus, we analyzed AraR-DNA interactions by in vitro quantitative DNase I footprinting and in vivo analysis of single-base-pair substitutions within the promoter regions of xsa and abnA. The results indicate that transcriptional repression of the abfA and xsa genes is achieved by a tightly controlled mechanism but that the regulation of abnA is more flexible. We suggest that the expression of genes encoding extracellular degrading enzymes of arabinose-containing polysaccharides, transport systems, and intracellular enzymes involved in further catabolism is regulated by a coordinate mechanism triggered by arabinose via AraR.
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Biossensores: Modernas Ferramentas para Monitorização e Controlo Analítico - Almeida, M. G. (Bol. Biotecnol., 2004)
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A combined approach to fault diagnosis in dynamic systems - Palma, L. B.; Coito, F.; Neves-Silva, R. (2004)
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Correlation between high power proton T(2) NMR relaxation and macroscopic viscoelastic properties - Alexandre, J.; Feio, G.; Marvao, M. R.; Figueiredo, J (Advanced Materials Forum Ii, 2004)
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Crystallization and preliminary X-ray diffraction analysis of the 16-haem cytochrome of Desulfovibrio gigas - Santos-Silva, T.; Diasa, J. M.; Bourenkov, G.; Bartunik, H.; Moura, I.; Romao, M. J. (Acta Crystallographica Section D-Biological Crystallography, 2004)
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Times Cited: 2 Romao, Maria/A-4115-2013; REQUIMTE, AL/H-9106-2013; Santos-Silva, Teresa/D-2050-2013; REQUIMTE, SMB/M-5694-2013; Moura, Isabel/D-6339-2013; REQUIMTE, UCIBIO/N-9846-2013 Romao, Maria/0000-0002-3004-0543; Moura, Isabel/0000-0003-0971-4977; 5 2

Direct electrochemistry of the Desulfovibrio gigas aldehyde oxidoreductase - dos Santos, M. M. C.; Sousa, P. M. P.; Goncalves, M. L. S.; Romao, M. J.; Moura, I.; Moura, J. J. G. (European Journal of Biochemistry, 2004)
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Times Cited: 10 Romao, Maria/A-4115-2013; Moura, Jose/D-6426-2013; REQUIMTE, AL/H-9106-2013; dos Santos, Margarida/H-7897-2012; REQUIMTE, SMB/M-5694-2013; Moura, Isabel/D-6339-2013; REQUIMTE, UCIBIO/N-9846-2013 Romao, Maria/0000-0002-3004-0543; dos Santos, Margarida/0000-0001-7531-757X; Moura, Isabel/0000-0003-0971-4977; 10

Electron-transfer kinetics in sulfonated aluminum phthalocyanines/cytochrome c complexes - Laia, C. A. T.; Costa, S. M. B.; Phillips, D.; Beeby, A. (Journal of Physical Chemistry B, 2004)
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Times Cited: 8 Laia, Cesar/C-8651-2011; Costa, Silvia/H-7766-2012; Beeby, Andrew/G-2866-2012; REQUIMTE, PHOTO/M-4229-2013; Costa, Silvia/M-8085-2013; REQUIMTE, LAQV/N-9835-2013 Laia, Cesar/0000-0001-6410-6072; Costa, Silvia/0000-0002-6978-8903; 8

Elementos para o estudo de um caso de sucesso na montagem automóvel em Portugal: a Opel Portugal [Elements for the study of a success case in automobile assembly: the Opel Portugal] - António Moniz (University Library of Munich, Germany, 2004)
The interest to study this factory of GM group in Portugal is due to the facto of being one of the oldest assembly lines of the automotive sector still operating in Portugal (it was founded in 1963). Besides that, it went recently across a very intensive technological change, and then would be interesting to know the organisation of work model chose. The Opel factory occupies at the moment the former one that belonged to Ford Lusitana. There it has being under production some modules that feed the assembly line on JIT and in sequence. Although there were severe difficulties to implement the case study at Opel, this report could be done using secondary information and several interviews at the factory and initial visits. This Opel factory was recently closed down in the frame of a GM European strategy for re-structuring.
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Keywords: assembly line; automotive industry; Portugal; restructuring; technology change

An Environment for Remote Control–The ERC System - Coito, F.; Palma, L. (2004)
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Epoxidation of cyclooctene catalyzed by dioxomolybdenum(VI) complexes in ionic liquids - Valente, A. A.; Petrovski, Z.; Branco, L. C.; C. A. M. Afonso; Pillinger, M.; Lopes, A. D.; Romao, C. C.; Nunes, C. D.; Goncalves, I. S. (Journal of Molecular Catalysis a-Chemical, 2004)
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Times Cited: 53 Nunes, Carla/D-7299-2012; Lopes, Andre/E-2136-2012; Romao, Carlos /D-1162-2010; Branco, Luis/C-6426-2013; Pillinger, Martyn/H-2639-2013; Goncalves, Isabel/H-3742-2013; Valente, Anabela/H-5922-2013; REQUIMTE, AL/H-9106-2013; REQUIMTE, PHOTO/M-4229-2013; Mateus Afonso, Carlos Alberto/M-7833-2013; REQUIMTE, LAQV/N-9835-2013; iMed.ULisboa, iMed.ULisboa/C-6292-2014; iMed.ULisboa, BioOrgChem /B-4209-2014 Lopes, Andre/0000-0002-9702-1216; Romao, Carlos /0000-0001-5061-3743; Branco, Luis/0000-0003-2520-1151; Pillinger, Martyn/0000-0002-6243-7692; Goncalves, Isabel/0000-0002-2836-7715; Mateus Afonso, Carlos Alberto/0000-0002-7284-5948; 55

Excited-state electron transfer in anthocyanins and related flavylium salts - da Silva, PF; J. C. Lima; Quina, FH; Macanita, AL (Journal of Physical Chemistry a, 2004)
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The family 11 carbohydrate-binding module of Clostridium thermocellum Lic26A-Cel5E accommodates beta-1,4- and beta-1,3-1,4-mixed linked glucans at a single binding site - Carvalho, A. L.; Goyal, A.; Prates, J. A. M.; Bolam, D. N.; Gilbert, H. J.; Pires, V. M. R.; Ferreira, L. M. A.; Planas, A.; Romao, M. J.; Fontes, Cmga (Journal of Biological Chemistry, 2004)
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Times Cited: 51 Carvalho, Ana Luisa/G-5638-2011; Romao, Maria/A-4115-2013; REQUIMTE, AL/H-9106-2013; Pires, Virginia/J-4799-2013; Prates, Jose/K-9934-2013; REQUIMTE, SMB/M-5694-2013; REQUIMTE, UCIBIO/N-9846-2013 Carvalho, Ana Luisa/0000-0002-3824-0240; Romao, Maria/0000-0002-3004-0543; Pires, Virginia/0000-0003-1307-3797; Prates, Jose/0000-0003-1032-5987; 57

A Fractional Linear System View of the Fractional Brownian Motion - Batista, A.G.; Ortigueira, M.D. (Nonlinear Dynamics, 2004)
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From Differences to Derivatives - Manuel Ortigueira; Fernando Coito (Fractional Calculus & Applied Analysis, 2004)
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From Differences to Derivatives - Ortigueira, M.D.; Coito, F. (Fractional Calculus and Applied Analysis, 2004)
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From Differences to Derivatives - Duarte Ortigueira, M.; Coito, F. (Institute of Mathematics and Informatics Bulgarian Academy of Sciences, 2004)
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Ground and excited-state electronoic interactions in poly(propylene amine) dendrimers functionalized with naphthy units: Effect of protonation and metal complexation - Pina, F; Maestri, M; Balzani, V.; Vogtle, F. (Chemphyschem, 2004)
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Times Cited: 26 Pina, Fernando/C-8161-2011; REQUIMTE, PHOTO/M-4229-2013; REQUIMTE, LAQV/N-9835-2013 Pina, Fernando/0000-0001-8529-6848; 26

Hb Yaounde beta 134(H12)Val -> Ala in association with Hb C beta 6(A3)Glu -> Lys in a Caucasian Portuguese family - Faustino, P.; Miranda, A.; Silva, M. D.; Alves, C.; Pinanco, I.; Ferreira, C.; Seixas, M. T.; Pina, F; Romao, L. (Hemoglobin, 2004)
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Times Cited: 1 1

Immobilization of oxomolybdenum species in a layered double hydroxide pillared by 2,2 '-bipyridine-5,5 '-dicarboxylate anions - Gago, S.; Pillinger, M.; Valente, A. A.; Santos, T. M.; Rocha, J.; Goncalves, I. S. (Inorganic Chemistry, 2004)
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Times Cited: 56 Rocha, Joao/A-2486-2010; Pillinger, Martyn/H-2639-2013; Goncalves, Isabel/H-3742-2013; Valente, Anabela/H-5922-2013; Santos, Teresa/K-7178-2013; REQUIMTE, PHOTO/M-4229-2013; Gago, Sandra/H-5413-2012; REQUIMTE, LAQV/N-9835-2013 Rocha, Joao/0000-0002-0417-9402; Pillinger, Martyn/0000-0002-6243-7692; Goncalves, Isabel/0000-0002-2836-7715; Gago, Sandra/0000-0003-0221-8508; 56

Incorporation of a (cyclopentadienyl)molybdenum oxo complex in MCM-41 and its use as a catalyst for olefin epoxidation - Abrantes, M.; Gago, S.; Valente, A. A.; Pillinger, M.; Goncalves, I. S.; Santos, T. M.; Rocha, J.; Romao, C. C. (European Journal of Inorganic Chemistry, 2004)
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Times Cited: 41 Rocha, Joao/A-2486-2010; Romao, Carlos /D-1162-2010; Abrantes, Marta/C-5140-2009; Pillinger, Martyn/H-2639-2013; Goncalves, Isabel/H-3742-2013; Valente, Anabela/H-5922-2013; Santos, Teresa/K-7178-2013; REQUIMTE, PHOTO/M-4229-2013; Gago, Sandra/H-5413-2012; REQUIMTE, LAQV/N-9835-2013 Rocha, Joao/0000-0002-0417-9402; Romao, Carlos /0000-0001-5061-3743; Pillinger, Martyn/0000-0002-6243-7692; Goncalves, Isabel/0000-0002-2836-7715; Gago, Sandra/0000-0003-0221-8508; 41

Interactions of a sulfonated aluminum phthalocyanine and cytochrome c in micellar systems: Binding and electron-transfer kinetics - Laia, C. A. T.; Costa, S. M. B. (Journal of Physical Chemistry B, 2004)
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Times Cited: 7 Laia, Cesar/C-8651-2011; Costa, Silvia/H-7766-2012; REQUIMTE, PHOTO/M-4229-2013; Costa, Silvia/M-8085-2013; REQUIMTE, LAQV/N-9835-2013 Laia, Cesar/0000-0001-6410-6072; Costa, Silvia/0000-0002-6978-8903; 7

Intramolecular fluorescence quenching of tyrosine by the peptide alpha-carbonyl group revisited - Noronha, M; J. C. Lima; Lamosa, P.; Santos, H.; Maycock, C; Ventura, R; Macanita, AL (Journal of Physical Chemistry a, 2004)
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Ionic liquids as a convenient new medium for the catalytic asymmetric dihydroxylation of olefins using a recoverable and reusable osmium/ligand - Branco, L. C.; C. A. M. Afonso (Journal of Organic Chemistry, 2004)
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Times Cited: 61 Branco, Luis/C-6426-2013; REQUIMTE, AL/H-9106-2013; REQUIMTE, PHOTO/M-4229-2013; Mateus Afonso, Carlos Alberto/M-7833-2013; REQUIMTE, LAQV/N-9835-2013; iMed.ULisboa, iMed.ULisboa/C-6292-2014; iMed.ULisboa, BioOrgChem /B-4209-2014 Branco, Luis/0000-0003-2520-1151; Mateus Afonso, Carlos Alberto/0000-0002-7284-5948; 62

Mo and W bis-MGD enzymes: nitrate reductases and formate dehydrogenases - Moura, J. J. G.; Brondino, C. D.; Trincao, J.; Romao, M. J. (Journal of Biological Inorganic Chemistry, 2004)
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Times Cited: 70 Romao, Maria/A-4115-2013; Moura, Jose/D-6426-2013; REQUIMTE, AL/H-9106-2013; REQUIMTE, SMB/M-5694-2013; REQUIMTE, UCIBIO/N-9846-2013 Romao, Maria/0000-0002-3004-0543; 74

Multistate properties of 7-(N,N-diethylamino)-4 '-hydroxyflavylium. An example of an unidirectional reaction cycle driven by pH - Moncada, MC; Fernandez, D; J. C. Lima; A. J. Parola; Lodeiro, C.; Folgosa, F.; Melo, MJ; Pina, F (Organic & Biomolecular Chemistry, 2004)
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Times Cited: 16 Melo, Maria Joao/C-8594-2011; Pina, Fernando/C-8161-2011; Folgosa, Filipe/F-7640-2012; Lodeiro, Carlos/B-4793-2013; REQUIMTE, AL/H-9106-2013; Lima, Joao/F-3658-2010; Group, Photochem&SC/M-4665-2013; REQUIMTE, PHOTO/M-4229-2013; REQUIMTE, C4O/M-5599-2013; Parola, A. Jorge/F-4048-2010; REQUIMTE, UCIBIO/N-9846-2013; REQUIMTE, LAQV/N-9835-2013 Melo, Maria Joao/0000-0001-7393-6801; Pina, Fernando/0000-0001-8529-6848; Folgosa, Filipe/0000-0001-5879-151X; Lodeiro, Carlos/0000-0001-5582-5446; Lima, Joao/0000-0003-0528-1967; Parola, A. Jorge/0000-0002-1333-9076; 16

Mutagenesis study on amino acids around the molybdenum centre of the periplasmic nitrate reductase from Ralstonia eutropha - Hettmann, T.; Siddiqui, R. A.; Frey, C.; Santos-Silva, T.; Romao, M. J.; Diekmann, S. (Biochemical and Biophysical Research Communications, 2004)
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Times Cited: 11 Romao, Maria/A-4115-2013; REQUIMTE, AL/H-9106-2013; Santos-Silva, Teresa/D-2050-2013; REQUIMTE, SMB/M-5694-2013; REQUIMTE, UCIBIO/N-9846-2013 Romao, Maria/0000-0002-3004-0543; 12

Paracoccus pantotrophus pseudoazurin is an electron donor to cytochrome c peroxidase - Pauleta, S. R.; Guerlesquin, F.; Goodhew, C. F.; Devreese, B.; Van Beeumen, J.; Pereira, A. S.; Moura, I.; Pettigrew, G. W. (Biochemistry, 2004)
The gene for pseudoazurin was isolated from Paracoccus pantotrophus LMD 52.44 and expressed in a heterologous system with a yield of 54.3 mg of pure protein per liter of culture. The gene and protein were shown to be identical to those from P. pantotrophus LMD 82.5. The extinction coefficient of the protein was re-evaluated and was found to be 3.00 mM(-1) cm(-1) at 590 nm. It was confirmed that the oxidized protein is in a weak monomer/dimer equilibrium that is ionic- strength-dependent. The pseudoazurin was shown to be a highly active electron donor to cytochrome c peroxidase, and activity showed an ionic strength dependence consistent with an electrostatic interaction. The pseudoazurin has a very large dipole moment, the vector of which is positioned at the putative electron-transfer site, His81, and is conserved in this position across a wide range of blue copper proteins. Binding of the peroxidase to pseudoazurin causes perturbation of a set of NMR resonances associated with residues on the His81 face, including a ring of lysine residues. These lysines are associated with acidic residues just back from the rim, the resonances of which are also affected by binding to the peroxidase. We propose that these acidic residues moderate the electrostatic influence of the lysines and so ensure that specific charge interactions do not form across the interface with the peroxidase.
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Photophysical and spectroscopic studies of Indigo derivatives in their keto and leuco forms - de Melo, JS; Moura, A. P.; Melo, MJ (Journal of Physical Chemistry A, 2004)
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Times Cited: 43 Melo, Maria Joao/C-8594-2011; Seixas de Melo, Sergio/A-5388-2008; REQUIMTE, AL/H-9106-2013; REQUIMTE, PHOTO/M-4229-2013; REQUIMTE, LAQV/N-9835-2013 Melo, Maria Joao/0000-0001-7393-6801; Seixas de Melo, Sergio/0000-0001-9708-5079; 43

Protein stabilization by osmolytes from hyperthermophiles - Effect of mannosylglycerate on the thermal unfolding of recombinant nuclease a from Staphylococcus aureus studied by picosecond time-resolved fluorescence and calorimetry - Faria, TQ; J. C. Lima; Bastos, M; Macanita, AL; Santos, H. (Journal of Biological Chemistry, 2004)
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Resultados provisórios do exerc{\'ıcio Delphi WorTiS (1ª fase) [Provisional results of the 1st round of Delphi WorTiS exercise] - António Moniz (University Library of Munich, Germany, 2004)
In this working paper are present the main provisional results of the first round of a Delphi survey held in Portugal on the automotive sector. It was done under the WorTiS project, developed by IET – Research Centre on Enterprise and Work Innovation, and financed by the Portuguese Ministry of Science and Technology. The majority of experts consider to have an average of less knowledge in almost all the scenario topics presented. Nevertheless, we considered specially the topics where the experts considered themselves to have some knowledge. There were no “irrelevant” topics considered as such by the expert panel. There are also no topics that is not considered a need for co-operation (that happens in jus tone case). The lack of technological infra-structrures was not considered as an hindered factor for the accomplishement of any scenario. The experts panel considered no other international competence besides US, Japan or Germany in these topics. Although the members of the expert panel were not as many as needed, These situations will be taken into consideration for a second round of the Delphi survey
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Keywords: automotive industry; Delphi survey; economical co-operation; scenario; technology

Sensor fault diagnosis based on neural observers and parameter estimation–application to the three-tank benchmark - Palma, L. B.; Coito, F.; Neves-Silva, R. (VI Portuguese Conf. on Automatic Control, Faro. Indexed at ISI Web of Science, 2004)
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Structural basis for the mechanism of Ca2+ activation of the di-heme cytochrome c peroxidase from Pseudomonas nautica 617 - Dias, J. M.; Alves, T.; Bonifacio, C.; Pereira, A. S.; Trincao, J.; Bourgeois, D.; Moura, I.; Romao, M. J. (Structure, 2004)
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Times Cited: 38 Romao, Maria/A-4115-2013; Pereira, Alice/D-7779-2013; REQUIMTE, AL/H-9106-2013; REQUIMTE, SMB/M-5694-2013; Moura, Isabel/D-6339-2013; REQUIMTE, UCIBIO/N-9846-2013 Romao, Maria/0000-0002-3004-0543; Moura, Isabel/0000-0003-0971-4977; 38

Synthesis and characterization of a manganese(II) acetonitrile complex supported on functionalized MCM-41 - Gago, S.; Zhang, Y. M.; Santos, A. M.; Kohler, K.; Kuhn, F. E.; Fernandes, J. A.; Pillinger, M.; Valente, A. A.; Santos, T. M.; Ribeiro-Claro, P. J. A.; Goncalves, I. S. (Microporous and Mesoporous Materials, 2004)
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Times Cited: 20 Fernandes, Jose/B-8073-2008; Ribeiro-Claro, Paulo/C-6705-2008; Kuhn, Fritz/A-3113-2010; Koehler, Klaus/D-2396-2013; Pillinger, Martyn/H-2639-2013; Goncalves, Isabel/H-3742-2013; Valente, Anabela/H-5922-2013; Santos, Teresa/K-7178-2013; Gago, Sandra/H-5413-2012; REQUIMTE, LAQV/N-9835-2013 Ribeiro-Claro, Paulo/0000-0001-5171-2153; Pillinger, Martyn/0000-0002-6243-7692; Goncalves, Isabel/0000-0002-2836-7715; Gago, Sandra/0000-0003-0221-8508; 20

Synthesis and properties of Zn-Al layered double hydroxides containing ferrocenecarboxylate anions - Gago, S.; Pillinger, M.; Santos, T. M.; Rocha, J.; Goncalves, I. S. (European Journal of Inorganic Chemistry, 2004)
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Times Cited: 21 Rocha, Joao/A-2486-2010; Pillinger, Martyn/H-2639-2013; Goncalves, Isabel/H-3742-2013; Santos, Teresa/K-7178-2013; REQUIMTE, PHOTO/M-4229-2013; Gago, Sandra/H-5413-2012; REQUIMTE, LAQV/N-9835-2013 Rocha, Joao/0000-0002-0417-9402; Pillinger, Martyn/0000-0002-6243-7692; Goncalves, Isabel/0000-0002-2836-7715; Gago, Sandra/0000-0003-0221-8508; 21

Unexpected alkyne transfer between gold and rhenium atoms and its application to the synthesis of alkynyl rhenium(I) compounds - Ferrer, M; Rodriguez, L; Rossell, O; J. C. Lima; Gomez-Sal, P; Martin, A (Organometallics, 2004)
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Unfolding of ubiquitin studied by picosecond time-resolved fluorescence of the tyrosine residue - Noronha, M; J. C. Lima; Bastos, M; Santos, H.; Macanita, AL (Biophysical Journal, 2004)
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X-ray crystal structure and EPR spectra of "arsenite-inhibited" Desulfovibrio gigas aldehyde dehydrogenase: A member of the xanthine oxidase family - Boer, D. R.; Thapper, A.; Brondino, C. D.; Romao, M. J.; Moura, J. J. G. (Journal of the American Chemical Society, 2004)
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Times Cited: 14 Thapper, Anders/A-6728-2010; Romao, Maria/A-4115-2013; Moura, Jose/D-6426-2013; REQUIMTE, AL/H-9106-2013; REQUIMTE, SMB/M-5694-2013; REQUIMTE, UCIBIO/N-9846-2013 Romao, Maria/0000-0002-3004-0543; 14

Zn-Al layered double hydroxide pillared by different dicarboxylate anions - Gago, S.; Pillinger, M.; Santos, T. M.; Goncalves, I. S. (Ceramics-Silikaty, 2004)
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Times Cited: 5 Pillinger, Martyn/H-2639-2013; Goncalves, Isabel/H-3742-2013; Santos, Teresa/K-7178-2013; REQUIMTE, PHOTO/M-4229-2013; Gago, Sandra/H-5413-2012; REQUIMTE, LAQV/N-9835-2013 Pillinger, Martyn/0000-0002-6243-7692; Goncalves, Isabel/0000-0002-2836-7715; Gago, Sandra/0000-0003-0221-8508; 5

{Digital Rights Management and Consumer Acceptability: A Multi-Disciplinary Discussion of Consumer Concerns and Expectations} - Helberger, Natali; Kerényi, Kristóf; Krings, Bettina; Lambers, Rik; Orwat, Carsten; Riehm, Ulrich; van Gompel, Stef; Dufft, Nicole (University Library of Munich, Germany, 2004)
The INDICARE project – the Informed Dialogue about Consumer Acceptability of DRM Solutions in Europe – has been set up to raise awareness about consumer and user issues of Digital Rights Management (DRM) solutions. One of the main goals of the INDICARE project is to contribute to the consensus-building among multiple players with heterogeneous interests in the digital environment. To promote this process and to contribute to the creation of a common level of understanding is the aim of the present report. It provides an overview of consumer concerns and expectations regarding DRMs, and discusses the findings from a social, legal, technical and business perspective. A general overview of the existing EC initiatives shows that questions of consumer acceptability of DRM have only recently begun to draw wider attention. A review of the relevant statements, studies and reports confirms that awareness of consumer concerns is still at a low level. Five major categories of concerns have been distinguished so far: (1) fair conditions of use and access to digital content, (2) privacy, (3) interoperability, (4) transparency and (5) various aspects of consumer friendliness. From the legal point of view, many of the identified issues go beyond the scope of copyright law, i.e. the field of law where DRM was traditionally discussed. Often they are a matter of general or sector-specific consumer protection law. Furthermore, it is still unclear to what extent technology and an appropriate design of technical solutions can provide an answer to some of the concerns of consumers. One goal of the technical chapter was exactly to highlight some of these technical possibilities. Finally, it is shown that consumer acceptability of DRM is important for the economic success of different business models based on DRM. Fair and responsive DRM design can be a profitable strategy, however DRM-free alternatives do exist too.
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Keywords: business models; consumers; Digital Rights Management; Intellectual property

{Elementos para o estudo de um caso de sucesso na montagem automóvel em Portugal: a Opel Portugal [Elements for the study of a success case in automobile assembly: the Opel Portugal]} - António Moniz (University Library of Munich, Germany, 2004)
The interest to study this factory of GM group in Portugal is due to the facto of being one of the oldest assembly lines of the automotive sector still operating in Portugal (it was founded in 1963). Besides that, it went recently across a very intensive technological change, and then would be interesting to know the organisation of work model chose. The Opel factory occupies at the moment the former one that belonged to Ford Lusitana. There it has being under production some modules that feed the assembly line on JIT and in sequence. Although there were severe difficulties to implement the case study at Opel, this report could be done using secondary information and several interviews at the factory and initial visits. This Opel factory was recently closed down in the frame of a GM European strategy for re-structuring.
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Keywords: assembly line; automotive industry; Portugal; restructuring; technology change

{Resultados provisórios do exercício Delphi WorTiS (1ª fase) [Provisional results of the 1st round of Delphi WorTiS exercise]} - António Moniz (University Library of Munich, Germany, 2004)
In this working paper are present the main provisional results of the first round of a Delphi survey held in Portugal on the automotive sector. It was done under the WorTiS project, developed by IET – Research Centre on Enterprise and Work Innovation, and financed by the Portuguese Ministry of Science and Technology. The majority of experts consider to have an average of less knowledge in almost all the scenario topics presented. Nevertheless, we considered specially the topics where the experts considered themselves to have some knowledge. There were no “irrelevant” topics considered as such by the expert panel. There are also no topics that is not considered a need for co-operation (that happens in jus tone case). The lack of technological infra-structrures was not considered as an hindered factor for the accomplishement of any scenario. The experts panel considered no other international competence besides US, Japan or Germany in these topics. Although the members of the expert panel were not as many as needed, These situations will be taken into consideration for a second round of the Delphi survey
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Keywords: automotive industry; Delphi survey; economical co-operation; scenario; technology

Broad-temperature range spectroscopy of the two-centre modular redox metalloprotein Desulfovibrio desulfuricans desulfoferrodoxin - Andersen, N. H.; Harnung, S. E.; Trabjerg, I.; Moura, I.; Moura, J. J. G.; Ulstrup, J. (Dalton Transactions, 2003)
The electronic-vibrational couplings of the two-centre non-heme iron protein Desulfovibrio desulfuricans desulfoferrodoxin (DFx) in three oxidation states, i.e. fully oxidised (grey), half-oxidised (pink), and fully reduced (colourless), have been investigated by variable temperature (VT) UV/VIS, MCD, CD, and EPR spectroscopy. The UV/VIS spectra of grey DFx at room temperature is characterised by broad charge transfer (CT) transitions associated with oxidised centre 1 (495 and 368 nm) and II (335 and 635 nm). The transitions are resolved at 78 K, substantiated by VT-MCD and -CD. The data offer novel information about the electronic-vibrational couplings of the transitions. Multiphonon bandshape analysis discloses strong contributions from both local Fe-S and S-C stretching and solvent/protein modes. A number of transitions are blue- or red-shifted compared with monomeric desulforedoxin, superoxide reductase or dismutase, and cloned Desulfovibrio vulgaris DFx fragments. Conversion from grey to pink DFx is accompanied by drastic electronic-vibrational changes of both centres. The data suggest that electron transfer and optical CT-transitions of DFx are controlled by environmental reorganization in the whole region between the metal centres.
Times Cited: 2

A further investigation of the cytochrome b5-cytochrome c complex - Banci, L.; Bertini, I.; Felli, I. C.; Krippahl, L.; Kubicek, K.; Moura, J. J.; Rosato, A. (J Biol Inorg Chem, 2003)
The interaction of reduced rabbit cytochrome b(5) with reduced yeast iso-1 cytochrome c has been studied through the analysis of (1)H-(15)N HSQC spectra, of (15)N longitudinal ( R(1)) and transverse ( R(2)) relaxation rates, and of the solvent exchange rates of protein backbone amides. For the first time, the adduct has been investigated also from the cytochrome c side. The analysis of the NMR data was integrated with docking calculations. The result is that cytochrome b(5) has two negative patches capable of interacting with a single positive surface area of cytochrome c. At low protein concentrations and in equimolar mixture, two different 1:1 adducts are formed. At high concentration and/or with excess cytochrome c, a 2:1 adduct is formed. All the species are in fast exchange on the scale of differences in chemical shift. By comparison with literature data, it appears that the structure of one 1:1 adduct changes with the origin or primary sequence of cytochrome b(5).
0949-8257 (Print)0949-8257 (Linking)Journal ArticleResearch Support, Non-U.S. Gov't
Keywords: *Protein Interaction Mapping; Animals; Computer Simulation; Cytochromes b5/*chemistry; Cytochromes c/*chemistry; Models, Molecular; Nuclear Magnetic Resonance, Biomolecular; Protein Binding; Rabbits

Impacto do desinvestimento no mercado local de emprego: o caso de uma unidade da indústria metalomecânica [Impact of divestment on the local employment market: a case of the metal industry] - António Moniz; Gomes, Cláudia (University Library of Munich, Germany, 2003)
This paper is a draft contribution for a definition of the concept of divestment. This topic is still very influenced by definitions from the fields of economics or management. Thus, from a group of definitions and approaches developed by different authors we try to elaborate on this divestment concept, searching for indicators and variables related to this practice. The founded indicators allow us to identify the main consequences and the potential social impacts due to divestment situations. Also we try to develop a methodology of research for analysis and impact framework that come from divestment action of companies.
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Keywords: company behaviour; divestment; local employment policies; metal industry; social implications

{Impacto do desinvestimento no mercado local de emprego: o caso de uma unidade da indústria metalomecânica [Impact of divestment on the local employment market: a case of the metal industry]} - António Moniz; Gomes, Cláudia (University Library of Munich, Germany, 2003)
This paper is a draft contribution for a definition of the concept of divestment. This topic is still very influenced by definitions from the fields of economics or management. Thus, from a group of definitions and approaches developed by different authors we try to elaborate on this divestment concept, searching for indicators and variables related to this practice. The founded indicators allow us to identify the main consequences and the potential social impacts due to divestment situations. Also we try to develop a methodology of research for analysis and impact framework that come from divestment action of companies.
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Keywords: company behaviour; divestment; local employment policies; metal industry; social implications

Electron transfer complexes of cytochrome c peroxidase from Paracoccus denitrificans containing more than one cytochrome - Pettigrew, G. W.; Pauleta, S. R.; Goodhew, C. F.; Cooper, A.; Nutley, M.; Jumel, K.; Harding, S. E.; Costa, C.; Krippahl, L.; Moura, I.; Moura, J. (Biochemistry, 2003)
According to the model proposed in previous papers [Pettigrew, G. W., Prazeres, S., Costa, C., Palma, N., Krippahl, L., and Moura, J. J. (1999) The structure of an electron-transfer complex containing a cytochrome c and a peroxidase, J. Biol. Chem. 274, 11383-11389; Pettigrew, G. W., Goodhew, C. F., Cooper, A., Nutley, M., Jumel, K., and Harding, S. E. (2003) Electron transfer complexes of cytochrome c peroxidase from Paracoccus denitrificans, Biochemistry 42, 2046-2055], cytochrome c peroxidase of Paracoccus denitrificans can accommodate horse cytochrome c and Paracoccus cytochrome c(550) at different sites on its molecular surface. Here we use (1)H NMR spectroscopy, analytical ultracentrifugation, molecular docking simulation, and microcalorimetry to investigate whether these small cytochromes can be accommodated simultaneously in the formation of a ternary complex. The pattern of perturbation of heme methyl and methionine methyl resonances in binary and ternary solutions shows that a ternary complex can be formed, and this is confirmed by the increase in the sedimentation coefficient upon addition of horse cytochrome c to a solution in which cytochrome c(550) fully occupies its binding site on cytochrome c peroxidase. Docking experiments in which favored binary solutions of cytochrome c(550) bound to cytochrome c peroxidase act as targets for horse cytochrome c and the reciprocal experiments in which favored binary solutions of horse cytochrome c bound to cytochrome c peroxidase act as targets for cytochrome c(550) show that the enzyme can accommodate both cytochromes at the same time on adjacent sites. Microcalorimetric titrations are difficult to interpret but are consistent with a weakened binding of horse cytochrome c to a binary complex of cytochrome c peroxidase and cytochrome c(550) and binding of cytochrome c(550) to the cytochrome c peroxidase that is affected little by the presence of horse cytochrome c in the other site. The presence of a substantial capture surface for small cytochromes on the cytochrome c peroxidase has implications for rate enhancement mechanisms which ensure that the two electrons required for re-reduction of the enzyme after reaction with hydrogen peroxide are delivered efficiently.
0006-2960 (Print)0006-2960 (Linking)Journal ArticleResearch Support, Non-U.S. Gov't
Keywords: Animals; Binding Sites; Calorimetry; Computer Simulation; Cytochrome c Group/*chemistry; Cytochrome-c Peroxidase/*chemistry; Cytochromes c/*chemistry; Electron Transport; Horses; Magnetic Resonance Spectroscopy; Models, Molecular; Multienzyme Complexes/chemistry; Paracoccus denitrificans/*enzymology; Protons; Solutions; Ultracentrifugation

The isolation and characterization of cytochrome c nitrite reductase subunits (NrfA and NrfH) from Desulfovibrio desulfuricans ATCC 27774. Re-evaluation of the spectroscopic data and redox properties - Almeida, M. G.; Macieira, S.; Goncalves, L. L.; Huber, R.; Cunha, C. A.; Romao, M. J.; Costa, C.; Lampreia, J.; Moura, J. J.; Moura, I. (Eur J Biochem, 2003)
The cytochrome c nitrite reductase is isolated from the membranes of the sulfate-reducing bacterium Desulfovibrio desulfuricans ATCC 27774 as a heterooligomeric complex composed by two subunits (61 kDa and 19 kDa) containing c-type hemes, encoded by the genes nrfA and nrfH, respectively. The extracted complex has in average a 2NrfA:1NrfH composition. The separation of ccNiR subunits from one another is accomplished by gel filtration chromatography in the presence of SDS. The amino-acid sequence and biochemical subunits characterization show that NrfA contains five hemes and NrfH four hemes. These considerations enabled the revision of a vast amount of existing spectroscopic data on the NrfHA complex that was not originally well interpreted due to the lack of knowledge on the heme content and the oligomeric enzyme status. Based on EPR and Mossbauer parameters and their correlation to structural information recently obtained from X-ray crystallography on the NrfA structure [Cunha, C.A., Macieira, S., Dias, J.M., Almeida, M.G., Goncalves, L.M.L., Costa, C., Lampreia, J., Huber, R., Moura, J.J.G., Moura, I. & Romao, M. (2003) J. Biol. Chem. 278, 17455-17465], we propose the full assignment of midpoint reduction potentials values to the individual hemes. NrfA contains the high-spin catalytic site (-80 mV) as well as a quite unusual high reduction potential (+150 mV)/low-spin bis-His coordinated heme, considered to be the site where electrons enter. In addition, the reassessment of the spectroscopic data allowed the first partial spectroscopic characterization of the NrfH subunit. The four NrfH hemes are all in a low-spin state (S = 1/2). One of them has a gmax at 3.55, characteristic of bis-histidinyl iron ligands in a noncoplanar arrangement, and has a positive reduction potential.
0014-2956 (Print)0014-2956 (Linking)Journal ArticleResearch Support, Non-U.S. Gov't
Keywords: *Cytochromes a1; *Cytochromes c1; Amino Acid Sequence; Bacterial Proteins/chemistry/genetics/*isolation &; Desulfovibrio/*enzymology/genetics; Electron Spin Resonance Spectroscopy; Electrophoresis, Polyacrylamide Gel; Heme/analysis; Molecular Sequence Data; Nitrate Reductases/chemistry/genetics/*isolation &; Oxidation-Reduction; Protein Conformation; Protein Subunits; purification/*metabolism; RNA-Binding Proteins/chemistry/genetics/*isolation &; Sequence Homology, Amino Acid; Solubility; Spectroscopy, Mossbauer; Transcription Factors/chemistry/genetics/*isolation &

A new symmetric fractional B-spline - Manuel Ortigueira (Signal Processing, 2003)
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Cytochrome c nitrite reductase from Desulfovibrio desulfuricans ATCC 27774. The relevance of the two calcium sites in the structure of the catalytic subunit (NrfA) - Cunha, C. A.; Macieira, S.; Dias, J. M.; Almeida, G.; Goncalves, L. L.; Costa, C.; Lampreia, J.; Huber, R.; Moura, J. J.; Moura, I.; Romao, M. J. (J Biol Chem, 2003)
The gene encoding cytochrome c nitrite reductase (NrfA) from Desulfovibrio desulfuricans ATCC 27774 was sequenced and the crystal structure of the enzyme was determined to 2.3-A resolution. In comparison with homologous structures, it presents structural differences mainly located at the regions surrounding the putative substrate inlet and product outlet, and includes a well defined second calcium site with octahedral geometry, coordinated to propionates of hemes 3 and 4, and caged by a loop non-existent in the previous structures. The highly negative electrostatic potential in the environment around hemes 3 and 4 suggests that the main role of this calcium ion may not be electrostatic but structural, namely in the stabilization of the conformation of the additional loop that cages it and influences the solvent accessibility of heme 4. The NrfA active site is similar to that of peroxidases with a nearby calcium site at the heme distal side nearly in the same location as occurs in the class II and class III peroxidases. This fact suggests that the calcium ion at the distal side of the active site in the NrfA enzymes may have a similar physiological role to that reported for the peroxidases.
0021-9258 (Print)0021-9258 (Linking)Journal ArticleResearch Support, Non-U.S. Gov't
Keywords: Amino Acid Sequence; Binding Sites; Calcium/*metabolism; Catalytic Domain/genetics; Cytochrome c Group/analysis/genetics/metabolism; Desulfovibrio/*enzymology; Molecular Sequence Data; Nitrite Reductases/*analysis/genetics/metabolism; Protein Conformation; Sequence Alignment

Isolation and characterisation of metallothionein from the clam Ruditapes decussatus - Simes, D. C.; Bebianno, M. J.; Moura, J. J. (Aquat Toxicol, 2003)
Metallothioneins (MT) were obtained after purification from metal-exposed clams (Ruditapes decussatus) using gel-permeation and ion-exchange chromatography. Four cadmium-metallothioneins (CdMTs) were resolved by ion-exchange chromatography and they all had similar molecular weights, high cadmium content and an absorption spectra indicative of the presence of characteristic Cd-S aggregates. The NH(2)-terminal sequence suggests the presence of at least two class I clam MT isoforms. For the other two putative clam CdMTs isolated, the results of the amino acid determination were inconclusive. One was slightly contaminated and the other one had a blocked NH(2)-terminal. These clam metalothioneins contain glycine, which seems to be a common feature of molluscan MT family and exhibited more similarity to oysters than to mussels. Further investigation on the inducibility of these isoforms will be necessary if clams are to be used as biomarkers of metal exposure.
0166-445X (Print)0166-445X (Linking)Journal Article
Keywords: Amino Acid Sequence; Animals; Bivalvia/*chemistry; Cadmium/isolation & purification; Metallothionein/*chemistry/classification/*isolation & purification; Protein Isoforms/classification/isolation & purification

Efficient Digital Self-Calibration of Video-Rate Pipeline ADCs using White Gaussian Noise - Martin Unterweissacher; João Goes; Nuno Paulino; Guiomar Evans; Manuel Ortigueira (IEEE International Symposium on Circuits and Systems, 2003)
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Efficient Digital Self-Calibration of Video-Rate Pipeline ADCs using White Gaussian Noise - Unterweissacher, M.; Goes, J.; Paulino, N.; Evans, G.; Ortigueira, M. (IEEE International Symposium on Circuits and Systems, 2003)
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Low-voltage low-power CMOS analogue circuits for Gaussian and uniform noise generation - Guiomar Evans; João Goes; Adolfo Steiger-Garção; Ortigueira, M.D.; Nuno Paulino; J. Sousa-Lopes (IEEE International Symposium on Circuits and Systems, 2003)
A CMOS analogue circuit for Gaussian noise generation as well as a novel circuit for transforming Gaussian noise into uniform noise, both designed for operating with a supply voltage of 1.5V, are presented. Both circuits are optimized for a 0.35 {\ensuremathμ}m standard CMOS technology using an equation-based design methodology based on genetic algorithms. Electrical simulations demonstrate that high noise amplitudes together with reasonable bandwidths can be achieved with relatively low power dissipation. Potential applications include self-calibration and on-chip self-testing of video-rate analogue-to-digital converters.
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Low-voltage low-power CMOS analogue circuits for Gaussian and uniform noise generation - Evans, G.; Goes, J.; Steiger-Garção, A.; Ortigueira, M.D.; Paulino, N.; J. Sousa-Lopes (IEEE International Symposium on Circuits and Systems. :145–148, 2003)
A CMOS analogue circuit for Gaussian noise generation as well as a novel circuit for transforming Gaussian noise into uniform noise, both designed for operating with a supply voltage of 1.5V, are presented. Both circuits are optimized for a 0.35 {\ensuremathμ}m standard CMOS technology using an equation-based design methodology based on genetic algorithms. Electrical simulations demonstrate that high noise amplitudes together with reasonable bandwidths can be achieved with relatively low power dissipation. Potential applications include self-calibration and on-chip self-testing of video-rate analogue-to-digital converters.

Tauroursodeoxycholic acid prevents Bax-induced membrane perturbation and cytochrome C release in isolated mitochondria - Rodrigues, C. M.; Sola, S.; Sharpe, J. C.; Moura, J. J.; Steer, C. J. (Biochemistry, 2003)
Bax is a potent pro-apoptotic member of the Bcl-2 protein family that localizes to the mitochondrial membrane during apoptosis. Tauroursodeoxycholic acid (TUDCA) modulates the apoptotic threshold, in part, by preventing Bax translocation both in vitro and in vivo. The mechanisms by which Bax induces and TUDCA inhibits release of cytochrome c are unclear. We show here that recombinant Bax protein induced cytochrome c release in isolated mitochondria without detectable swelling. Co-incubation with TUDCA prevented efflux of mitochondrial factors and proteolytic processing of caspases in cytosolic extracts. Spectroscopic analyses of mitochondria exposed to Bax revealed increased polarity and fluidity of the membrane lipid core as well as altered protein order, indicative of Bax binding, together with loss of spin-label paramagnetism, characteristic of oxidative damage. TUDCA markedly abrogated the Bax-induced membrane perturbation. In conclusion, our results indicate that Bax protein directly induces cytochrome c release from mitochondria through a mechanism that does not require the permeability transition. Rather, it is accompanied by changes in the organization of membrane lipids and proteins. TUDCA is a potent inhibitor of Bax association with mitochondria. Thus, TUDCA modulates apoptosis by suppressing mitochondrial membrane perturbation through pathways that are also independent of the mitochondrial permeability transition.
0006-2960 (Print)0006-2960 (Linking)Journal ArticleResearch Support, Non-U.S. Gov't
Keywords: Animals; Apoptosis/drug effects/physiology; bcl-2-Associated X Protein; Caspases/metabolism; Cytochrome c Group/*secretion; Cytosol/enzymology; Enzyme Activation/drug effects/physiology; Humans; Intracellular Membranes/*enzymology/metabolism/*pathology/secretion; Male; Membrane Lipids/metabolism; Membrane Potentials/drug effects/physiology; Mitochondria, Liver/*enzymology/metabolism/*pathology/secretion; Mitochondrial Swelling/drug effects/physiology; Oxidation-Reduction/drug effects; Permeability/drug effects; Protein Binding/drug effects/physiology; Protein Processing, Post-Translational/drug effects/physiology; Proteins/metabolism; Proto-Oncogene Proteins c-bcl-2/antagonists & inhibitors/physiology; Proto-Oncogene Proteins/*antagonists & inhibitors/metabolism/*physiology; Rats; Rats, Wistar; Recombinant Proteins/antagonists & inhibitors/metabolism/pharmacology; Taurochenodeoxycholic Acid/pharmacology/*physiology

Assembling Toyota in Portugal - Machado, Tiago; António Moniz (University Library of Munich, Germany, 2003)
A lot has been written over the last decade with regard to Toyota and the productive model associated to it (toyota-ism). And more specifically concerning the "(…) best-seller that changed the... sociological world" (Castillo, 1998: 31). But the case of Salvador Caetano’s Ovar Industrial Division (OID), that assembles Toyota light commercial vehicles in Portugal, allows us to put forward a sub-hypothesis that fits into the analysis schema proposed in the First GERPISA International Program – "In short, GERPISA members considered that the plurality of models was much a plausible hypothesis deserving testing as that of the diffusion of a unique model (…)" (Boyer, Freyssenet, 2001: 42). So we add: and within Toyota itself, is it not true that different productive models co-exist – especially when delocalised – depending, amongst other factors, on the degree of Toyota participation – in terms of capital and technology transfer – in the local company (strong or weak) and on the markets to be reached (internal or external)? If so, what work system can we expect to find in a plant that presents such peculiar characteristics as this one?
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Keywords: automotive industry; Japan; organization of work; Portugal

Assembling Toyota in Portugal - Machado, Tiago; António Moniz (University Library of Munich, Germany, 2003)
A lot has been written over the last decade with regard to Toyota and the productive model associated to it (toyota-ism). And more specifically concerning the "(…) best-seller that changed the... sociological world" (Castillo, 1998: 31). But the case of Salvador Caetano’s Ovar Industrial Division (OID), that assembles Toyota light commercial vehicles in Portugal, allows us to put forward a sub-hypothesis that fits into the analysis schema proposed in the First GERPISA International Program – "In short, GERPISA members considered that the plurality of models was much a plausible hypothesis deserving testing as that of the diffusion of a unique model (…)" (Boyer, Freyssenet, 2001: 42). So we add: and within Toyota itself, is it not true that different productive models co-exist – especially when delocalised – depending, amongst other factors, on the degree of Toyota participation – in terms of capital and technology transfer – in the local company (strong or weak) and on the markets to be reached (internal or external)? If so, what work system can we expect to find in a plant that presents such peculiar characteristics as this one?
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Keywords: automotive industry; Japan; organization of work; Portugal

Molecular aspects of denitrification/nitrate dissimilation - Moura, I.; Cabrito, I.; Almeida, G.; Cunha, C.; Romao, M. J.; Moura, J. J. G. (Journal of Inorganic Biochemistry, 2003)
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Times Cited: 011th International Conference on Biological Inorganic ChemistryJul 19-23, 2003Caims, australia

Modeling protein complexes with BiGGER - Krippahl, L.; Moura, J. J.; Palma, P. N. (Proteins, 2003)
This article describes the method and results of our participation in the Critical Assessment of PRediction of Interactions (CAPRI) experiment, using the protein docking program BiGGER (Bimolecular complex Generation with Global Evaluation and Ranking) (Palma et al., Proteins 2000;39:372-384). Of five target complexes (CAPRI targets 2, 4, 5, 6, and 7), only one was successfully predicted (target 6), but BiGGER generated reasonable models for targets 4, 5, and 7, which could have been identified if additional biochemical information had been available.
1097-0134 (Electronic)0887-3585 (Linking)Evaluation StudiesJournal Article
Keywords: *Models, Molecular; Algorithms; Animals; Binding Sites; Macromolecular Substances; Protein Interaction Mapping; Proteins/*chemistry/*metabolism

Electrochemical studies on small electron transfer proteins using membrane electrodes - dos Santos, M. M. C.; de Sousa, P. M. P.; Goncalves, M. L. S.; Krippahl, L.; Moura, J. J. G.; Lojou, E.; Bianco, P. (Journal of Electroanalytical Chemistry, 2003)
Membrane electrodes (ME) were constructed using gold, glassy carbon and pyrolytic graphite supports and a dialysis membrane, and used to study the electrochemical behavior of small size electron transfer proteins: monohemic cytochrome c(522) from Pseudomonas nautica and cytochrome c(533) as well as rubredoxin from Desulfovibrio vulgaris. Different electrochemical techniques were used including cyclic voltammetry (CV), square wave voltammetry (SW) and differential pulse voltammetry (DP). A direct electrochemical response was obtained in all cases except with rubredoxin where a facilitator was added to the protein solution entrapped between the membrane and the electrode surface. Formal potentials and heterogeneous charge transfer rate constants were determined from the voltammetric data. The influence of the ionic strength and the pH of the medium on the electrochemical response at the ME were analyzed. The benefits from the use of the ME in protein electrochemistry and its role in modulating the redox behavior are analyzed. A critical comparison is presented with data obtained at non-MEs. Finally, the interactions that must be established between the proteins and the electrode surfaces are discussed, thereby modeling molecular interactions that occur in biological systems. (C) 2002 Elsevier Science B.V. All rights reserved.
Times Cited: 16

NMR solution structures of two mutants of desulforedoxin - Goodfellow, B. J.; Rusnak, F.; Moura, I.; Ascenso, C. S.; Moura, J. J. (J Inorg Biochem, 2003)
The differences in geometry at the metal centres in the two known [Fe-4S] proteins rubredoxin (Rd) and desulforedoxin (Dx) are postulated to be a result of the different spacing of the C-terminal cysteine pair in the two proteins. In order to address this question, two mutants of Desulfovibrio gigas Dx with modified cysteinyl spacing were prepared and their solution structures have been determined by NMR. Mutant 1 of Dx (DxM1) has a single glycine inserted between the adjacent cysteines (C28 and C29) found in the wild type Dx sequence. Mutant 3 (DxM3) has two amino acid residues, -P-V-, inserted between C28 and C29 in order to mimic the primary sequence found in Rd from Desulfovibrio gigas. The solution structure of DxM1 exists, like wild type Dx, as a dimer in solution although the single glycine inserted between the adjacent cysteines disrupts the stability of the dimer resulting in exchange between a dimer state and a small population of another, probably monomeric, state. For DxM3 the two amino acid residues inserted between the adjacent cysteines results in a monomeric protein that has a global fold near the metal centre very similar to that found in Rd.
0162-0134 (Print)0162-0134 (Linking)Journal ArticleResearch Support, Non-U.S. Gov't
Keywords: *Mutation; *Nuclear Magnetic Resonance, Biomolecular; Iron-Sulfur Proteins/*chemistry/*genetics; Models, Molecular; Protein Conformation; Solutions/chemistry

Ca2+ and the bacterial peroxidases: the cytochrome c peroxidase from Pseudomonas stutzeri - Timoteo, C. G.; Tavares, P; Goodhew, C. F.; Duarte, L. C.; Jumel, K.; Girio, F. M. F.; Harding, S.; Pettigrew, G. W.; Moura, I. (Journal of Biological Inorganic Chemistry, 2003)
The production of cytochrome c peroxidase (CCP) from Pseudomonas (Ps.) stutzeri (ATCC 11607) was optimized by adjusting the composition of the growth medium and aeration of the culture. The protein was isolated and characterized biochemically and spectroscopically in the oxidized and mixed valence forms. The activity of Ps. stutzeri CCP was studied using two different ferrocytochromes as electron donors: Ps. stutzeri cytochrome C-551 (the physiological electron donor) and horse heart cytochrome c. These electron donors interact differently with Ps. stutzeri CCP, exhibiting different ionic strength dependence. The CCP from Paracoccus (Pa.) denitrificans was proposed to have two different Ca2+ binding sites: one usually occupied (site I) and the other either empty or partially occupied in the oxidized enzyme (site II). The Ps. stutzeri enzyme was purified in a form with tightly bound Ca2+. The affinity for Ca2+ in the mixed valence enzyme is so high that Ca2+ returns to it from the EGTA which was added to empty the site in the oxidized enzyme. Molecular mass determination by ultracentrifugation and behavior on gel filtration chromatography have revealed that this CCP is isolated as an active dimer, in contrast to the Pa. denitrificans CCP which requires added Ca2+ for formation of the dimer and also for activation of the enzyme. This is consistent with the proposal that Ca2+ in the bacterial peroxidases influences the monomer/dimer equilibrium and the transition to the active form of the enzyme. Additional Ca2+ does affect both the kinetics of oxidation of horse heart cytochrome c (but not cytochrome C-551) and higher aggregation states of the enzyme. This suggests the presence of a superficial Ca2+ binding site of low affinity.
Times Cited: 14

Formation of a stable cyano-bridged dinuclear iron cluster following oxidation of the superoxide reductases from Treponema pallidum and Desulfovibrio vulgaris with K(3)Fe(CN)(6) - Auchere, F.; Raleiras, P.; Benson, L.; Venyaminov, S. Y.; Tavares, P; Moura, J. J.; Moura, I.; Rusnak, F. (Inorg Chem, 2003)
Superoxide reductases catalyze the monovalent reduction of superoxide anion to hydrogen peroxide. Spectroscopic evidence for the formation of a dinuclear cyano-bridged adduct after K(3)Fe(CN)(6) oxidation of the superoxide reductases neelaredoxin from Treponema pallidum and desulfoferrodoxin from Desulfovibrio vulgaris was reported. Oxidation with K(3)Fe(CN)(6) reveals a band in the near-IR with lambda(max) at 1020 nm, coupled with an increase of the iron content by almost 2-fold. Fourier transform infrared spectroscopy provided additional evidence with CN-stretching vibrations at 2095, 2025-2030, and 2047 cm(-)(1), assigned to a ferrocyanide adduct of the enzyme. Interestingly, the low-temperature electronic paramagnetic resonance (EPR) spectra of oxidized TpNlr reveal at least three different species indicating structural heterogeneity in the coordination environment of the active site Fe ion. Given the likely 6-coordinate geometry of the active site Fe(3+) ion in the ferrocyanide adduct, we propose that the rhombic EPR species can serve as a model of a hexacoordinate form of the active site.
0020-1669 (Print)0020-1669 (Linking)Journal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.
Keywords: *Iron-Binding Proteins; Bacterial Proteins; Binding Sites; Carrier Proteins/chemistry/metabolism; Catalysis; Desulfovibrio vulgaris/*enzymology; Electron Spin Resonance Spectroscopy; Ferricyanides/*metabolism; Iron/*chemistry/*metabolism; Models, Molecular; Oxidation-Reduction; Oxidoreductases/*chemistry/*metabolism; Superoxide Dismutase; Treponema pallidum/*enzymology

Ca2+ and the bacterial peroxidases: the cytochrome c peroxidase from Pseudomonas stutzeri - Timóteo, C G; Tavares, P; Goodhew, C. F.; Duarte, L. C.; Jumel, K.; Girio, F. M. F.; Harding, S.; Pettigrew, G. W.; Moura, I. (JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY, 2003)
The production of cytochrome c peroxidase (CCP) from Pseudomonas (Ps.) stutzeri (ATCC 11607) was optimized by adjusting the composition of the growth medium and aeration of the culture. The protein was isolated and characterized biochemically and spectroscopically in the oxidized and mixed valence forms. The activity of Ps. stutzeri CCP was studied using two different ferrocytochromes as electron donors: Ps. stutzeri cytochrome C-551 (the physiological electron donor) and horse heart cytochrome c. These electron donors interact differently with Ps. stutzeri CCP, exhibiting different ionic strength dependence. The CCP from Paracoccus (Pa.) denitrificans was proposed to have two different Ca2+ binding sites: one usually occupied (site I) and the other either empty or partially occupied in the oxidized enzyme (site II). The Ps. stutzeri enzyme was purified in a form with tightly bound Ca2+. The affinity for Ca2+ in the mixed valence enzyme is so high that Ca2+ returns to it from the EGTA which was added to empty the site in the oxidized enzyme. Molecular mass determination by ultracentrifugation and behavior on gel filtration chromatography have revealed that this CCP is isolated as an active dimer, in contrast to the Pa. denitrificans CCP which requires added Ca2+ for formation of the dimer and also for activation of the enzyme. This is consistent with the proposal that Ca2+ in the bacterial peroxidases influences the monomer/dimer equilibrium and the transition to the active form of the enzyme. Additional Ca2+ does affect both the kinetics of oxidation of horse heart cytochrome c (but not cytochrome C-551) and higher aggregation states of the enzyme. This suggests the presence of a superficial Ca2+ binding site of low affinity.
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Spectroscopic characterization of a novel 2 x 4Fe-4S ferredoxin isolated from Desulfovibrio desulfuricans ATCC 27774 - Rodrigues, P. M.; Moura, I.; Macedo, A. L.; Moura, J. J. G. (Inorganica Chimica Acta, 2003)
A novel iron-sulfur containing protein, a ferredoxin (Fd), was purified to homogeneity from the extract of Desulfovibrio desulfuricans American type culture collection (ATCC) 27774. The purified protein is a 13.4 kDa homodimer with a polypeptide chain of 60 amino acids residues, containing eight cysteines that coordinate two [4Fe-4S] clusters. The protein is shown to be air sensitive and cluster conversions take place. We structurally characterize a redox state that contains two [4Fe-4S] cores. 1D and 2D H-1 NMR studies are reported on form containing the clusters in the oxidized state. Based on the nuclear Overhauser effect (NOE), relaxation measurements and comparison of the present data with the available spectra of the analogous 8Fe Fds, the cluster ligands were specifically assigned to the eight-cysteinyl residues. (C) 2003 Elsevier B.V. All rights reserved.
Times Cited: 1

Activation of N2O reduction by the fully reduced micro4-sulfide bridged tetranuclear Cu Z cluster in nitrous oxide reductase - Ghosh, S.; Gorelsky, S. I.; Chen, P.; Cabrito, I.; Moura, J. J.; Moura, I.; Solomon, E. I. (J Am Chem Soc, 2003)
The tetranuclear CuZ cluster catalyzes the two-electron reduction of N2O to N2 and H2O in the enzyme nitrous oxide reductase. This study shows that the fully reduced 4CuI form of the cluster correlates with the catalytic activity of the enzyme. This is the first demonstration that the S = 1/2 form of CuZ can be further reduced. Complementary DFT calculations support the experimental findings and demonstrate that N2O binding in a bent mu-1,3-bridging mode to the 4CuI form is most efficient due to strong back-bonding from two reduced copper atoms. This back-donation activates N2O for electrophilic attack by a proton.
0002-7863 (Print)0002-7863 (Linking)Journal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.
Keywords: Copper/*chemistry/metabolism; Electron Spin Resonance Spectroscopy; Enzyme Activation; Kinetics; Models, Molecular; Nitrous Oxide/*chemistry/metabolism; Oxidation-Reduction; Oxidoreductases/*chemistry/metabolism; Sulfides/chemistry/metabolism; Thermodynamics

Differentiation of isomeric C8-substituted alkylaniline adducts of guanine by electrospray ionization and tandem quadrupole ion trap mass spectrometry - Li, L; Chiarelli, MP; Branco, P. S.; Antunes, AM; M.M. Marques; Goncalves, L. L.; BELAND, FA (JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY, 2003)
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15th Sanibel Conference on Mass Spectrometry, SANIBEL ISLAND, FL, 2003

Óxido Nítrico na Abordagem da Hipertensão Pulmonar no Contexto de Cirurgia Cardíaca do Adulto - Timóteo, Ana Teresa; Miguel Abecassis; Pedro Baptista; Rebocho, {Maria José; Queiroz E Melo, Joáo (Revista Portuguesa de Cardiologia, 2003)
Pulmonary hypertension is a significant problem to take into account in the post-operative management of cardiac patients, especially valvular patients. Inhaled nitric oxide allows more effective control of pulmonary pressure and other hemodynamic parameters, with better post-operative results. We present a clinical case of a patient with mitral stenosis and severe pulmonary hypertension, with post-operative hemodynamic instability, in which we used inhaled nitric oxide for better control of pulmonary pressures and to help ventilator weaning.
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Keywords: Cardiac surgery; Inhaled nitric oxide; Pulmonary hypertension

Kinetic behavior of Desulfovibrio gigas aldehyde oxidoreductase encapsulated in reverse micelles - Andrade, S. L.; Brondino, C. D.; Kamenskaya, E. O.; Levashov, A. V.; Moura, J. J. (Biochem Biophys Res Commun, 2003)
We report the kinetic behavior of the enzyme aldehyde oxidoreductase (AOR) from the sulfate reducing bacterium Desulfovibrio gigas (Dg) encapsulated in reverse micelles of sodium bis-(2-ethylhexyl) sulfosuccinate in isooctane using benzaldehyde, octaldehyde, and decylaldehyde as substrates. Dg AOR is a 200-kDa homodimeric protein that catalyzes the conversion of aldehydes to carboxylic acids. Ultrasedimentation analysis of Dg AOR-containing micelles showed the presence of 100-kDa molecular weight species, confirming that the Dg AOR subunits can be dissociated. UV-visible spectra of encapsulated Dg AOR are indistinguishable from the enzyme spectrum in solution, suggesting that both protein fold and metal cofactor are kept intact upon encapsulation. The catalytic constant (k(cat)) profile as a function of the micelle size W(0) (W(0)=[H(2)O]/[AOT]) using benzaldehyde as substrate showed two bell-shaped activity peaks at W(0)=20 and 26. Furthermore, enzymatic activity for octaldehyde and decylaldehyde was detected only in reverse micelles. Like for the benzaldehyde kinetics, two peaks with both similar k(cat) values and W(0) positions were obtained. EPR studies using spin-labeled reverse micelles indicated that octaldehyde and benzaldehyde are intercalated in the micelle membrane. This suggests that, though Dg AOR is found in the cytoplasm of bacterial cells, the enzyme may catalyze the reaction of substrates incorporated into a cell membrane.
0006-291X (Print)0006-291X (Linking)Journal ArticleResearch Support, Non-U.S. Gov't
Keywords: *Micelles; Aldehyde Reductase/*metabolism; Aldehydes/metabolism; Desulfovibrio/*enzymology; Kinetics

Cu(II) and Ni(II) complexes with dipyridine-containing macrocyclic polyamines with different binding units - Anda, C.; Bazzicalupi, C; Bencini, A; Bianchi, A; Fornasari, P; Giorgi, C; Valtancoli, B; Lodeiro, C.; A. J. Parola; Pina, F (Dalton Transactions, 2003)
The coordination features of the two dipyridine-containing polyamine macrocycles 2,5,8,11,14-pentaaza[ 15][ [15](2,2')[1,15]-bipyridylophane (L1) and 4,4'-(2,5,8,11,14-pentaaza[15]-[15](2,2')-bipyridylophane) (L2) toward Cu(II) and Ni(II) have been studied by means of potentiometric and spectrophotometric UV-vis titrations in aqueous solutions. While in L1 all the nitrogen donor atoms are convergent inside the macrocyclic cavity, in L2 the heteroaromatic nitrogen atoms are located outside. Ligands L1 and L2 form stable mono- and dinuclear complexes with Cu(II). In the case of Ni(II) coordination, only L1 gives dinuclear complexes, while L2 can form only mononuclear species. In the Cu(II) or Ni(II) complexes with L1 the metal(s) are lodged inside the macrocyclic cavity, coordinated to the heteroaromatic nitrogens. As shown by the crystal structure of the [CuL1](2+) and [NiL1](2+) cations, at least one of the two benzylic nitrogens is not coordinated and facile protonation of the complex takes place at neutral or slightly acidic pH values. The particular molecular architecture of L2, which displays two well-separated binding moieties, strongly affects its coordination behavior. In the mononuclear [ CuL2](2+) complex, the metal is encapsulated inside the cavity, not coordinated by the dipyridine unit. Protonation of the complex, however, occurs on the aliphatic polyamine chain and gives rise to translocation of the metal outside the cavity, bound to the heteroaromatic nitrogens. In the [NiL2](2+) complex the metal is coordinated by the dipyridine nitrogens, outside the macrocyclic cavity. Thermodynamic and/or kinetic considerations may explain the different behavior with respect to the corresponding Cu(II) complex.
ISI Document Delivery No.: 659JYTimes Cited: 15 Cited Reference Count: 74 Anda, C Bazzicalupi, C Bencini, A Bianchi, A Fornasari, P Giorgi, C Valtancoli, B Lodeiro, C Parola, AJ Pina, F Pina, Fernando/C-8161-2011; Lodeiro, Carlos/B-4793-2013; Parola, A. Jorge/F-4048-2010 Lodeiro, Carlos/0000-0001-5582-5446; Parola, A. Jorge/0000-0002-1333-9076 Royal soc chemistry Cambridge

Energetics and dynamics of naphthalene polyaminic derivatives. Influence of structural design in the balance static vs dynamic excimer formation - de Melo, JS; Pina, J; Pina, F; Lodeiro, C.; A. J. Parola; J. C. Lima; Albelda, MT; Clares, MP; Garcia-Espana, E; Soriano, C (Journal of Physical Chemistry A, 2003)
Two new fluorescent macrocyclic structures bearing two naphthalene (Np) units at both ends of a cyclic polyaminic chain were investigated with potentiometric, fluorescence (steady-state and time-resolved) and laser flash photolysis techniques. The fluorescence emission studies show the presence of an excimer species whose formation depends on the protonation state of the polyamine chains implying the existence of a bending movement (occurring in both the ground and in the first singlet excited state), which allows the two naphthalene units to approach and interact. For comparison purposes, one bis-chromophoric compound containing a rigid chain (piperazine unit) was also investigated. Its emission spectra shows a unique band decaying single exponentially thus showing that no excimer is formed. With the two new ligands, excimer formation occurs in all situations even at very acidic pH values when the protonation of the polyamine bridges is extensive. Coexistence of ground-state dimers with dynamic excimers was established based on steady-state and time-resolved fluorescence data. The energetics of excimer formation and dissociation were determined in ethanol and water. Different methods of decay analysis (independent decay deconvolution, global analysis and excimer deconvolution with monomer) were used to extract the kinetic (rate constants for excimer formation, dissociation, and decay) and thermodynamic parameters. In ethanol and acidified ethanol:water mixtures, an additional short decay time was found to exist and assigned to a dimer, whose presence is assumed to be responsible by the decrease in activation energy for excimer formation in this solvent. The results are globally discussed in terms of the small architectural differences that can induce significant changes in the photophysical behavior of the three studied compounds.
ISI Document Delivery No.: 756BXTimes Cited: 22 Cited Reference Count: 51 de Melo, JS Pina, J Pina, F Lodeiro, C Parola, AJ Lima, JC Albelda, MT Clares, MP Garcia-Espana, E Soriano, C Seixas de Melo, Sergio/A-5388-2008; Pina, Fernando/C-8161-2011; Albelda, M. Teresa/J-5929-2012; Lodeiro, Carlos/B-4793-2013; Parola, A. Jorge/F-4048-2010; REQUIMTE, AL/H-9106-2013; Pina, Joao /H-9948-2013; Lima, Joao/F-3658-2010 Seixas de Melo, Sergio/0000-0001-9708-5079; Lodeiro, Carlos/0000-0001-5582-5446; Parola, A. Jorge/0000-0002-1333-9076; Lima, Joao/0000-0003-0528-1967 Amer chemical soc Washington

Intramolecular excimer formation in a tripodal polyamine receptor containing three naphthalene fluorophores - Albelda, MT; Garcia-Espana, E; Gil, L; J. C. Lima; Lodeiro, C.; de Melo, JS; Melo, MJ; A. J. Parola; Pina, F; Soriano, C (Journal of Physical Chemistry B, 2003)
comprehensive investigation on the energetics and dynamics of a new fluorescent sensor constituted by a tripodal polyamine receptor containing three naphthalene fluorophores, compound L, is reported. The influence of external factors such as the solvent, hydrogen ion concentration, and temperature in the photophysics of the sensor is discussed. The temperature dependence of monomer/excimer interconversion of L revealed an average percentage relative sensitivity of 4.5%/degreesC thus portending its use as a temperature sensor. The activation energy for excimer formation (E-1 = 12 kJ mol(-1)) and dissociation (E-1 = 57 kJ mol(-1)), entropy change (DeltaS = -128 J K-1 mol(-1)), and the binding energy of the excimer (DeltaH = 45 kJ mol(-1)) were obtained in water at acidic pH values and ethanol (E-1 = 15 kJ mol(-1), E-1 = 40 kJ mol(-1), DeltaS = -61 J K-1 mol(-1), and DeltaH = 25 kJ mol(-1)). The dependence of the kinetic and thermodynamic parameters on the dielectric constant of the medium and on the degree of protonation of the polyamine chain was interpreted in terms of the excimer destabilization provoked by the electrostatic repulsion between the positively charged chains.
ISI Document Delivery No.: 697BATimes Cited: 40 Cited Reference Count: 33 Albelda, MT Garcia-Espana, E Gil, L Lima, JC Lodeiro, C de Melo, JS Melo, MJ Parola, AJ Pina, F Soriano, C Melo, Maria Joao/C-8594-2011; Pina, Fernando/C-8161-2011; Seixas de Melo, Sergio/A-5388-2008; Albelda, M. Teresa/J-5929-2012; Lodeiro, Carlos/B-4793-2013; Parola, A. Jorge/F-4048-2010; REQUIMTE, AL/H-9106-2013; Lima, Joao/F-3658-2010 Seixas de Melo, Sergio/0000-0001-9708-5079; Lodeiro, Carlos/0000-0001-5582-5446; Parola, A. Jorge/0000-0002-1333-9076; Lima, Joao/0000-0003-0528-1967 Amer chemical soc Washington

Metal complexes with a new N4O3 amine pendant-armed macrocyclic ligand: Synthesis, characterization, crystal structures, and fluorescence studies - Vicente, M.; Bastida, R.; Lodeiro, C.; Macias, A.; A. J. Parola; Valencia, L.; Spey, S. E. (Inorganic Chemistry, 2003)
The synthesis of a new oxaaza macrocyclic ligand, L, derived from O-1,O-7-bis(2-formylphenyl)-1,4,7-trioxaheptane and tren containing an amine terminal pendant arm, and its metal complexation with alkaline earth (M = Ca2+, Sr2+, Ba2+), transition (M = Co2+, Ni2+, Cu2+, Zn2+, Cd2+), post-transition (M = Pb2+), and Y3+ and lanthanide (M = La3+, Er3+) metal ions are reported. Crystal structures of [H2L](ClO4)(2).3H(2)O, [PbL](ClO4)(2), and [ZnLCl](ClO4).H2O are also reported. In the [PbL] complex, the metal ion is located inside the macrocyclic cavity coordinated by all N4O3 donor atoms while, in the [ZnLCI] complex, the metal ion is encapsulated only by the nitrogen atoms present in the ligand. pi-pi interactions in the [H2L](ClO4)(2).3H(2)O and [PbL](ClO4)(2) structures are observed. Protonation and Zn2+, Cd2+, and Cu2+ complexation were studied by means of potentiometric, UV-vis, and fluorescent emission measurements. The 10-fold fluorescence emission increase observed in the pH range 7-9 in the presence of Zn2+ leads to L as a good sensor for this biological metal in water solution.
ISI Document Delivery No.: 733WPTimes Cited: 56 Cited Reference Count: 63 Vicente, M Bastida, R Lodeiro, C Macias, A Parola, AJ Valencia, L Spey, SE Lodeiro, Carlos/B-4793-2013; Parola, A. Jorge/F-4048-2010; REQUIMTE, AL/H-9106-2013 Lodeiro, Carlos/0000-0001-5582-5446; Parola, A. Jorge/0000-0002-1333-9076; Amer chemical soc Washington

Reductive activation of aerobically purified Desulfovibrio vulgaris hydrogenase: Mossbauer characterization of the catalytic H cluster - Huynh, B. H.; Tavares, P; Pereira, A. S.; Moura, I.; Moura, J. J. G. (Biochemistry and Physiology of Anaerobic Bacteria, 2003)
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Studies on the preparation of 4-ethoxyalkyliden and 4-aminoalkyliden-5(4H)-oxazolones - Matos, MRPN; Gois, PMP; Mata, MLEN; E. J. Cabrita; C. A. M. Afonso (Synthetic Communications, 2003)
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Supramolecular interactions of hexacyanocobaltate(III) with polyamine receptors containing a terminal anthracene sensor - Rodriguez, L; Alves, S; J. C. Lima; A. J. Parola; Pina, F; Soriano, C; Albelda, T; Garcia-Espana, E (Journal of Photochemistry and Photobiology a-Chemistry, 2003)
The fluorescence emission properties of a series of chemosensors containing a polyamine receptor bearing an anthracene signaling unit were studied. The fluorescence emission intensity is dependent on the protonation degree of the receptor, the fully protonated form exhibiting the highest emission intensity. By removing protons from the nitrogens a quenching effect can be observed, due to an electron-transfer from the amine to the excited fluorophore. The rate constant of the quenching process is exponentially dependent on the distance of the nitrogen from which the electron is transferred (beta = 0.6Angstrom(-1)). The ability of the chemosensors for signaling anions was tested through the model anion hexacyanocobaltate(III). The temperature dependence of the association constants shows that at least for this compound, the change in solvation entropy is probably the controlling parameter to account for the binding. (C) 2003 Elsevier Science B.V. All rights reserved.
ISI Document Delivery No.: 694QBTimes Cited: 13 Cited Reference Count: 24 Rodriguez, L Alves, S Lima, JC Parola, AJ Pina, F Soriano, C Albelda, T Garcia-Espana, E Pina, Fernando/C-8161-2011; Rodriguez, Laura/A-4169-2011; Albelda, M. Teresa/J-5929-2012; Parola, A. Jorge/F-4048-2010; REQUIMTE, AL/H-9106-2013; Lima, Joao/F-3658-2010 Rodriguez, Laura/0000-0003-1289-1587; Parola, A. Jorge/0000-0002-1333-9076; Lima, Joao/0000-0003-0528-1967 Elsevier science sa Lausanne

Distinct molecular mechanisms involved in carbon catabolite repression of the arabinose regulon in Bacillus subtilis - Inácio, José Manuel; Costa, Carla; Isabel de Sá-Nogueira (Microbiology, 2003)
The Bacillus subtilis proteins involved in the utilization of L-arabinose are encoded by the araABDLMNPQ–abfA metabolic operon and by the araE/araR divergent unit. Transcription from the ara operon, araE transport gene and araR regulatory gene is induced by L-arabinose and negatively controlled by AraR. Additionally, expression of both the ara operon and the araE gene is regulated at the transcriptional level by glucose repression. Here, by transcriptional fusion analysis in different mutant backgrounds, it is shown that CcpA most probably complexed with HPr-Ser46-P plays the major role in carbon catabolite repression of the ara regulon by glucose and glycerol. Site-directed mutagenesis and deletion analysis indicate that two catabolite responsive elements (cres) present in the ara operon (cre araA and cre araB) and one cre in the araE gene (cre araE) are implicated in this mechanism. Furthermore, cre araA located between the promoter region of the ara operon and the araA gene, and cre araB placed 2 kb downstream within the araB gene are independently functional and both contribute to glucose repression. In Northern blot analysis, in the presence of glucose, a CcpA-dependent transcript consistent with a message stopping at cre araB was detected, suggesting that transcription ‘roadblocking’ of RNA polymerase elongation is the most likely mechanism operating in this system. Glucose exerts an additional repression of the ara regulon, which requires a functional araR.
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Baseline Comparative Report – Deliverable 8 – ECOPADEV - Amado, Miguel (European Comission, 2003)

Biotecnologia microbiana - Spencer-Martins, I.; de Sá-Nogueira, I. (Biotecnologia, 2003)
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Cell wall branches, penicillin resistance and the secrets of the MurM protein - A. Fiser; S. R. Filipe; A. Tomasz (Trends Microbiol, 2003)

Different electroclinical manifestations of the epilepsy associated with Hypothalamic Hamartomas connecting to the middle or posterior Hypothalamus - Alberto Leal; Ana Moreira,; Conceição Robalo; Constança Ribeiro (Epilepsia, 2003)

Fault diagnosis based on black-box models with application to a liquid-level system - Palma, L. B.; Coito, F. V.; Silva, RN (Emerging Technologies and Factory Automation, 2003. Proceedings. ETFA’03. IEEE Conference. 2:739–746.: IEEE, 2003)
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New BCH-Derived Sequences for CDMA Systems - Ricardo, CN; J. A. Inácio; Gerald, JA; Ortigueira, M.D. (46th IEEE - Midwest Symposium on Circuits and Systems. :1255–1258, 2003)
New BCH-derived PN-EB (pseudo-noise even balanced) sequences suitable to be used in CDMA systems are presented in this paper. It is assumed a new definition for processing gain, which better accounts for the system performance regarding the narrow band noise rejection, and it is shown how to obtain high processing gain values, namely, by using zero mean spreading signals in channels with selective noise. The new sequences have low autocorrelation levels, exist in large numbers and can provide higher processing gain with selective noise.

NMR redox studies of flavocytochrome c3 from Shewanella frigidimarina - Miguel Pessanha; Turner, David L.; Emma L. Rothery; Pankhurst, Katherine L.; Graeme A. Reid; Stephen K. Chapman; Xavier, António V.; Salgueiro, C.A. (Inorganica Chimica Acta, 2003)
Flavocytochrome c3 is a periplasmic fumarate reductase with Mr 63.8 kDa, isolated from Shewanella frigidimarina NCIMB400. NMR spectroscopy was tested for its potential to elucidate the oxidation profile of each of the four haem groups in the enzyme, using the strategy developed previously to perform the thermodynamic characterization of small tetrahaem cytochromes (FEBS Lett. 314 (1992) 155). This work shows that, despite the large size of the protein, 2D-NMR NOESY experiments can be used to obtain the network of chemical exchange connectivities, between the signals of specific haem groups in sequential oxidation stages.

Patologias no 4 piso do Edifício da Mango – Avenida Alfredo da Silva no Barreiro - Amado, Miguel (2003)

A Prototype software for the Diagnostic of Atrial fibrillation - Carvoeiras, P.; Rodrigues, M.J.; A.G., B; Ortigueira, M.D. (XXIV Congresso Português de Cardiologia and Revista Portuguesa de Cardiologia. III, 2003)
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The respiratory chain of the thermophilic archaeon Sulfolobus metallicus: studies on the type-II NADH dehydrogenase - Bandeiras, Tiago M; Salgueiro, C.A.; Huber, Harald; Gomes, C.M.; Teixeira, Miguel (Biochimica et Biophysica Acta (BBA) - Bioenergetics, 2003)
The membranes of the thermoacidophilic archaeon Sulfolobus metallicus exhibit an oxygen consumption activity of 0.5 nmol O2 min−1 mg−1, which is insensitive to rotenone, suggesting the presence of a type-II NADH dehydrogenase. Following this observation, the enzyme was purified from solubilised membranes and characterised. The pure protein is a monomer with an apparent molecular mass of 49 kDa, having a high N-terminal amino acid sequence similarity towards other prokaryotic enzymes of the same type. It contains a covalently attached flavin, which was identified as being FMN by 31P-NMR spectroscopy, a novelty among type-II NADH dehydrogenases. Metal analysis showed the absence of iron, indicating that no FeS clusters are present in the protein. The average reduction potential of the FMN group was determined to be +160 mV, at 25 °C and pH 6.5, by redox titrations monitored by visible spectroscopy. Catalytically, the enzyme is a NADH:quinone oxidoreductase, as it is capable of transferring electrons from NADH to several quinones, including ubiquinone-1, ubiquinone-2 and caldariella quinone. Maximal turnover rates of 195 μmol NADH oxidized min−1 mg−1 at 60 °C were obtained using ubiquinone-2 as electron acceptor, after enzyme dilution and incubation with phospholipids.

Spatial and temporal organization of replicating Escherichia coli chromosomes - I. F. Lau; S. R. Filipe; B. Soballe; O. -A. Okstad; F. -X. Barre; D. J. Sherratt (Mol Microbiol, 2003)

Thermodynamic characterization of a tetrahaem cytochrome isolated from a facultative aerobic bacterium, Shewanella frigidimarina: a putative redox model for flavocytochrome c3 - Miguel Pessanha; Ricardo O. Louro; Correia, Ilídio J; Emma L. Rothery; Pankhurst, Kate L; Graeme A. Reid; Stephen K. Chapman; Turner, David L.; Salgueiro, C.A. (Biochemical Journal, 2003)
The facultative aerobic bacterium Shewanella frigidimarina produces a small c-type tetrahaem cytochrome (86 residues) under anaerobic growth conditions. This protein is involved in the respiration of iron and shares 42% sequence identity with the N-terminal domain of a soluble flavocytochrome, isolated from the periplasm of the same bacterium, which also contains four c-type haem groups. The thermodynamic properties of the redox centres and of an ionizable centre in the tetrahaem cytochrome were determined using NMR and visible spectroscopy techniques. This is the first detailed thermodynamic study performed on a tetrahaem cytochrome isolated from a facultative aerobic bacterium and reveals that this protein presents unique features. The redox centres have negative and different redox potentials, which are modulated by redox interactions between the four haems (covering a range of 8–56mV) and by redox–Bohr interactions between the haems and an ionizable centre (-4 to -36mV) located in close proximity to haem III. All of the interactions between the five centres are clearly dominated by electrostatic effects and the microscopic reduction potential of haem III is the one most affected by the oxidation of the other haems and by the protonation state of the molecule. Altogether, this study indicates that the tetrahaem cytochrome isolated from S. frigidimarina (Sfc) has the thermodynamic properties to work as an electron wire between its redox partners. Considering the high degree of sequence identity between Sfc and the cytochrome domain of flavocytochrome c3, the structural similarities of the haem core, and that the macroscopic potentials are also identical, the results obtained in this work are rationalized in order to put forward a putative redox model for flavocytochrome c3.

Cellulosome assembly revealed by the crystal structure of the cohesin-dockerin complex - Carvalho, A. L.; Dias, F. M. V.; Prates, J. A. M.; Nagy, T.; Gilbert, H. J.; Davies, G. J.; Ferreira, L. M. A.; Romao, M. J.; Fontes, Cmga (Proceedings of the National Academy of Sciences of the United States of America, 2003)
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Times Cited: 130 Davies, Gideon/A-9042-2011; Dias, Fernando/I-4861-2012; Carvalho, Ana Luisa/G-5638-2011; Romao, Maria/A-4115-2013; REQUIMTE, AL/H-9106-2013; Prates, Jose/K-9934-2013; REQUIMTE, SMB/M-5694-2013; REQUIMTE, UCIBIO/N-9846-2013 Davies, Gideon/0000-0002-7343-776X; Dias, Fernando/0000-0001-8109-2063; Carvalho, Ana Luisa/0000-0002-3824-0240; Romao, Maria/0000-0002-3004-0543; Prates, Jose/0000-0003-1032-5987; 131

Clusters in polymer-surfactant AOT microemulsions probed by excited state quenching kinetics - Paulo, P. M. R.; Laia, C. A. T.; Costa, S. M. B. (Journal of Physical Chemistry B, 2003)
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Times Cited: 6 Laia, Cesar/C-8651-2011; Costa, Silvia/H-7766-2012; Paulo, Pedro/H-8157-2012; REQUIMTE, PHOTO/M-4229-2013; Costa, Silvia/M-8085-2013; REQUIMTE, LAQV/N-9835-2013 Laia, Cesar/0000-0001-6410-6072; Paulo, Pedro/0000-0002-8001-4810; Costa, Silvia/0000-0002-6978-8903; 6

Complexation of aluminum(III) by anthocyanins and synthetic flavylium salts - A source for blue and purple color - Moncada, MC; Moura, S.; Melo, MJ; Roque, A.; Lodeiro, C.; Pina, F (Inorganica Chimica Acta, 2003)
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Times Cited: 19 Melo, Maria Joao/C-8594-2011; Pina, Fernando/C-8161-2011; Lodeiro, Carlos/B-4793-2013; REQUIMTE, AL/H-9106-2013; REQUIMTE, PHOTO/M-4229-2013; REQUIMTE, C4O/M-5599-2013; REQUIMTE, UCIBIO/N-9846-2013; REQUIMTE, LAQV/N-9835-2013 Melo, Maria Joao/0000-0001-7393-6801; Pina, Fernando/0000-0001-8529-6848; Lodeiro, Carlos/0000-0001-5582-5446; 19

Correlating natural ageing and Xenon irradiation of Paraloid (R) B72 applied on stone - Bracci, S.; Melo, MJ (Polymer Degradation and Stability, 2003)
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Times Cited: 20 Melo, Maria Joao/C-8594-2011; REQUIMTE, PHOTO/M-4229-2013; REQUIMTE, LAQV/N-9835-2013 Melo, Maria Joao/0000-0001-7393-6801; 22

Crystallization and preliminary X-ray diffraction analysis of the di-haem cytochrome c peroxidase from Pseudomonas stutzeri - Bonifácio, Cecília; Cunha, Carlos A.; Müller, Axel; Timóteo, Cristina G.; Dias, João M.; Moura, Isabel; Romão, Maria João (Acta Crystallographica Section D, 2003)
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Keywords: Cytochromes; di-haem cytochrome c peroxidase; low-affinity and high-affinity calcium-binding sites; Pseudomonas stutzeri.

Crystallization and preliminary X-ray diffraction analysis of the di-haem cytochrome c peroxidase from Pseudomonas stutzeri - Bonifacio, C.; Cunha, C. A.; Muller, A.; Timoteo, C. G.; Dias, J. M.; Moura, I.; Romao, M. J. (Acta Crystallographica Section D-Biological Crystallography, 2003)
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Times Cited: 0 Romao, Maria/A-4115-2013; REQUIMTE, AL/H-9106-2013; Timoteo, Cristina/D-7275-2013; REQUIMTE, SMB/M-5694-2013; Moura, Isabel/D-6339-2013; REQUIMTE, UCIBIO/N-9846-2013 Romao, Maria/0000-0002-3004-0543; Moura, Isabel/0000-0003-0971-4977; 2 0

Cytochrome c nitrite reductase from Desulfovibrio desulfuricans ATCC 27774 - The relevance of the two calcium sites in the structure of the catalytic subunit (NrfA) - Cunha, C. A.; Macieira, S.; Dias, J. M.; Almeida, G.; Goncalves, L. L.; Costa, C.; Lampreia, J.; Huber, R.; Moura, J. J. G.; Moura, I.; Romao, M. J. (Journal of Biological Chemistry, 2003)
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Times Cited: 47 Costa, Cristina/A-9966-2012; Romao, Maria/A-4115-2013; Lampreia, Jorge/A-9927-2012; Moura, Jose/D-6426-2013; Almeida, Maria Gabriela/D-8265-2013; REQUIMTE, AL/H-9106-2013; REQUIMTE, SMB/M-5694-2013; Moura, Isabel/D-6339-2013; REQUIMTE, UCIBIO/N-9846-2013 Costa, Cristina/0000-0002-8611-9023; Romao, Maria/0000-0002-3004-0543; Lampreia, Jorge/0000-0001-8846-0041; Almeida, Maria Gabriela/0000-0002-4508-7379; Moura, Isabel/0000-0003-0971-4977; 47

The dynamics of ultrafast excited state proton transfer in anionic micelles - Giestas, L; Yihwa, C; J. C. Lima; Vautier-Giongo, C; Lopes, A; Macanita, AL; Quina, FH (Journal of Physical Chemistry a, 2003)
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Failure Analysis on a Process Plant Model Based on Adaptive Filter Techniques - Palma, L.; Coito, F.; Neves-Silva, R. (2003)
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Fault diagnosis based on black-box models with application to a liquid-level system - Palma, L. B.; Coito, F. V.; Silva, RN (Emerging Technologies and Factory Automation, 2003. Proceedings. ETFA’03. IEEE Conference, 2003)
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Fault tolerant control approach applied to the three-tank system - Palma, L.; Neves-Silva, R.; Coito, F. (2003)
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Formation of a stable cyano-bridged dinuclear iron cluster following oxidation of the superoxide reductases from Treponema pallidum and Desulfovibrio vulgaris with K3Fe(CN)(6) - Auchere, F.; Raleiras, P.; Benson, L.; Venyaminov, S. Y.; Tavares, P; Moura, J. J. G.; Moura, I.; Rusnak, F. (INORGANIC CHEMISTRY, 2003)
Superoxide reductases catalyze the monovalent reduction of superoxide anion to hydrogen peroxide. Spectroscopic evidence for the formation of a dinuclear cyano-bridged adduct after K3Fe-(CN)(6) oxidation of the superoxide reductases neelaredoxin from Treponema pallidum and desulfoferrodoxin from Desulfovibrio vulgaris was reported. Oxidation with K3Fe(CN)(6) reveals a band in the near-IR with lambda(max) at 1020 nm, coupled with an increase of the iron content by almost 2-fold. Fourier transform infrared spectroscopy provided additional evidence with CN-stretching vibrations at 2095, 2025-2030, and 2047 cm(-1), assigned to a ferrocyanide adduct of the enzyme. Interestingly, the low-temperature electronic paramagnetic resonance (EPR) spectra of oxidized TpNIr reveal at least three different species indicating structural heterogeneity in the coordination environment of the active site Fe ion. Given the likely 6-coordinate geometry of the active site Fe3+ ion in the ferrocyanide adduct, we propose that the rhombic EPR species can serve as a model of a hexacoordinate form of the active site.
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Glass transition relaxation and fragility in two room temperature ionic liquids - Ramos, J. J. M.; C. A. M. Afonso; Branco, L. C. (Journal of Thermal Analysis and Calorimetry, 2003)
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Times Cited: 42 Branco, Luis/C-6426-2013; REQUIMTE, PHOTO/M-4229-2013; Mateus Afonso, Carlos Alberto/M-7833-2013; REQUIMTE, LAQV/N-9835-2013; iMed.ULisboa, iMed.ULisboa/C-6292-2014; iMed.ULisboa, BioOrgChem /B-4209-2014 Branco, Luis/0000-0003-2520-1151; Mateus Afonso, Carlos Alberto/0000-0002-7284-5948; 42

Ground- and excited-state proton transfer in anthocyanins: From weak acids to superphotoacids - Moreira, PF; Giestas, L; Yihwa, C; Vautier-Giongo, C; Quina, FH; Macanita, AL; J. C. Lima (Journal of Physical Chemistry a, 2003)
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The isolation and characterization of cytochrome c nitrite reductase subunits (NrfA and NrfH) from Desulfovibrio desulfuricans ATCC 27774 - Re-evaluation of the spectroscopic data and redox properties - Almeida, M. G.; Macieira, S.; Goncalves, L. L.; Huber, R.; Cunha, C. A.; Romao, M. J.; Costa, C.; Lampreia, J.; Moura, J. J. G.; Moura, I. (European Journal of Biochemistry, 2003)
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Times Cited: 32 Costa, Cristina/A-9966-2012; Romao, Maria/A-4115-2013; Lampreia, Jorge/A-9927-2012; Moura, Jose/D-6426-2013; Almeida, Maria Gabriela/D-8265-2013; REQUIMTE, AL/H-9106-2013; REQUIMTE, SMB/M-5694-2013; Moura, Isabel/D-6339-2013; REQUIMTE, UCIBIO/N-9846-2013 Costa, Cristina/0000-0002-8611-9023; Romao, Maria/0000-0002-3004-0543; Lampreia, Jorge/0000-0001-8846-0041; Almeida, Maria Gabriela/0000-0002-4508-7379; Moura, Isabel/0000-0003-0971-4977; 32

Linear ditopic acetylide gold or mercury complexes: synthesis and photophysic studies X-ray crystal structure of PPh4[Au(C CC5H4N)(2)] - Ferrer, M; Rodriguez, L; Rossell, O; Pina, F; J. C. Lima; Bardia, MF; Solans, X (Journal of Organometallic Chemistry, 2003)
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Mammalian molybdo-flavoenzymes, an expanding family of proteins: structure, genetics, regulation, function and pathophysiology - Garattini, E.; Mendel, R.; Romao, M. J.; Wright, R.; Terao, M. (Biochemical Journal, 2003)
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Times Cited: 110 Romao, Maria/A-4115-2013; REQUIMTE, AL/H-9106-2013; REQUIMTE, SMB/M-5694-2013; REQUIMTE, UCIBIO/N-9846-2013 Romao, Maria/0000-0002-3004-0543; 1 116

Molecular aspects of denitrification/nitrate dissimilation - Moura, I.; Cabrito, I.; Almeida, G.; Cunha, C.; Romao, M. J.; Moura, J. J. G. (Journal of Inorganic Biochemistry, 2003)
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Times Cited: 0 Romao, Maria/A-4115-2013; Moura, Jose/D-6426-2013; Almeida, Maria Gabriela/D-8265-2013; REQUIMTE, AL/H-9106-2013; REQUIMTE, SMB/M-5694-2013; Moura, Isabel/D-6339-2013; REQUIMTE, UCIBIO/N-9846-2013 Romao, Maria/0000-0002-3004-0543; Almeida, Maria Gabriela/0000-0002-4508-7379; Moura, Isabel/0000-0003-0971-4977; 11th International Conference on Biological Inorganic Chemistry Jul 19-23, 2003 Caims, australia 0

Multistate/multifunctional systems. A thermodynamic, kinetic, and photochemical investigation of the 4 '-dimethylaminoflavylium compound - Roque, A.; Lodeiro, C.; Pina, F; Maestri, M; Dumas, S.; Passaniti, P.; Balzani, V. (Journal of the American Chemical Society, 2003)
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Times Cited: 36 Pina, Fernando/C-8161-2011; Lodeiro, Carlos/B-4793-2013; REQUIMTE, PHOTO/M-4229-2013; REQUIMTE, C4O/M-5599-2013; REQUIMTE, UCIBIO/N-9846-2013; REQUIMTE, LAQV/N-9835-2013 Pina, Fernando/0000-0001-8529-6848; Lodeiro, Carlos/0000-0001-5582-5446; 36

Mutagenesis study on the role of a lysine residue highly conserved in formate dehydrogenases and periplasmic nitrate reductases - Hettmann, T.; Siddiqui, R. A.; van Langen, J.; Frey, C.; Romao, M. J.; Diekmann, S. (Biochemical and Biophysical Research Communications, 2003)
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Times Cited: 12 Romao, Maria/A-4115-2013; REQUIMTE, AL/H-9106-2013; REQUIMTE, SMB/M-5694-2013; REQUIMTE, UCIBIO/N-9846-2013 Romao, Maria/0000-0002-3004-0543; 12

Neural Observer-Based Approach to Fault Diagnosis applied to a Liquid Level System - Palma, L.; Coito, F.; Neves-Silva, R. (2003)
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New BCH-Derived Sequences for CDMA Systems - Ricardo, CN; J. A. Inácio; Gerald, JA; Ortigueira, M.D. (46th IEEE - Midwest Symposium on Circuits and Systems, 2003)
New BCH-derived PN-EB (pseudo-noise even balanced) sequences suitable to be used in CDMA systems are presented in this paper. It is assumed a new definition for processing gain, which better accounts for the system performance regarding the narrow band noise rejection, and it is shown how to obtain high processing gain values, namely, by using zero mean spreading signals in channels with selective noise. The new sequences have low autocorrelation levels, exist in large numbers and can provide higher processing gain with selective noise.
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On the initial conditions continuous-time fractional linear systems - Manuel Ortigueira (Signal Processing, 2003)
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Potentiometric, NMR, and fluorescence-emission studies on the binding of adenosine 5 '-triphosphate (ATP) by open-chain polyamine receptors containing naphthylmethyl and/or anthrylmethyl groups - Albelda, MT; Aguilar, J; Alves, S; Aucejo, R; Diaz, P; Lodeiro, C.; J. C. Lima; Garcia-Espana, E; Pina, F; Soriano, C (Helvetica Chimica Acta, 2003)
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Practices and trends of telework in the Portuguese industry: the results of surveys in the textile, metal and software sectors - Urze, Paula; António Moniz; Barroso, Sónia (University Library of Munich, Germany, 2003)
The aim of the TeleRisk Project on labour relations and professional risks within the context of teleworking in Portugal – supported by IDICT – Institute for Development and Inspection of Working Conditions (Ministry of Labour), is to study the practices and forms of teleworking in the manufacturing sectors in Portugal. The project chose also the software industry as a reference sector, even though it does not intend to exclude from the study any other sector of activity or the so-called “hybrid” forms of work. However, the latter must have some of the characteristics of telework. The project thus takes into account the so-called “traditional” sectors of activity, namely textile and machinery and metal engineering (machinery and equipment), not usually associated to this type of work. However, telework could include, in the so-called “traditional” sectors, other variations that are not found in technologically based sectors. One of the evaluation methods for the dynamics associated to telework consisted in carrying out surveys by means of questionnaires, aimed at employers in the sectors analysed. This paper presents some of the results of those surveys. It is important to mention that, being a preliminary analysis, it means that it does not pretend to have exhausted all the issues in the survey, but has meant that it shows the bigger tendencies, in terms of teleworking practices, of the Portuguese industry.
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Keywords: Manufacturing; organisation of work; Portugal; teleworking

A Prototype software for the Diagnostic of Atrial fibrillation - Carvoeiras, P.; Rodrigues, M.J.; Batista A.G.; Ortigueira, M.D. (XXIV Congresso Português de Cardiologia and Revista Portuguesa de Cardiologia, 2003)
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Special Issue on Fractional signal Processing and applications - Manuel Ortigueira; Machado, JA (Elsevier, 2003)
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Spectroscopy of photoinduced charge-transfer reactions between tetrasulfonated aluminium phthalocyanine and methyl viologen - Laia, C. A. T.; Costa, S. M. B.; Phillips, D.; Parker, A. W. (Photochemical & Photobiological Sciences, 2003)
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Times Cited: 13 Laia, Cesar/C-8651-2011; Parker, Anthony/G-5445-2011; Costa, Silvia/H-7766-2012; REQUIMTE, PHOTO/M-4229-2013; Costa, Silvia/M-8085-2013; REQUIMTE, LAQV/N-9835-2013 Laia, Cesar/0000-0001-6410-6072; Costa, Silvia/0000-0002-6978-8903; 14

Synthesis and properties of tetra-alkyl-dimethylguanidinium salts as a potential new generation of ionic liquids - Mateus, N. M. M.; Branco, L. C.; Lourenco, N. M. T.; C. A. M. Afonso (Green Chemistry, 2003)
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Times Cited: 93 Lourenco, Nuno/K-5088-2012; Branco, Luis/C-6426-2013; REQUIMTE, AL/H-9106-2013; REQUIMTE, PHOTO/M-4229-2013; Mateus Afonso, Carlos Alberto/M-7833-2013; REQUIMTE, LAQV/N-9835-2013; iMed.ULisboa, iMed.ULisboa/C-6292-2014; iMed.ULisboa, BioOrgChem /B-4209-2014 Lourenco, Nuno/0000-0001-9329-2724; Branco, Luis/0000-0003-2520-1151; Mateus Afonso, Carlos Alberto/0000-0002-7284-5948; 94

{Practices and trends of telework in the Portuguese industry: the results of surveys in the textile, metal and software sectors} - Urze, Paula; António Moniz; Barroso, Sónia (University Library of Munich, Germany, 2003)
The aim of the TeleRisk Project on labour relations and professional risks within the context of teleworking in Portugal – supported by IDICT – Institute for Development and Inspection of Working Conditions (Ministry of Labour), is to study the practices and forms of teleworking in the manufacturing sectors in Portugal. The project chose also the software industry as a reference sector, even though it does not intend to exclude from the study any other sector of activity or the so-called “hybrid” forms of work. However, the latter must have some of the characteristics of telework. The project thus takes into account the so-called “traditional” sectors of activity, namely textile and machinery and metal engineering (machinery and equipment), not usually associated to this type of work. However, telework could include, in the so-called “traditional” sectors, other variations that are not found in technologically based sectors. One of the evaluation methods for the dynamics associated to telework consisted in carrying out surveys by means of questionnaires, aimed at employers in the sectors analysed. This paper presents some of the results of those surveys. It is important to mention that, being a preliminary analysis, it means that it does not pretend to have exhausted all the issues in the survey, but has meant that it shows the bigger tendencies, in terms of teleworking practices, of the Portuguese industry.
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Keywords: Manufacturing; organisation of work; Portugal; teleworking

A Digital-Domain Self-Calibration Technique for Video-Rate Pipeline A?D Converters Using Gaussian-White Noise - João Goes; Nuno Paulino; Manuel Ortigueira (IEE Electronics Letters, 2002)
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Spectroscopic and electronic structure studies of the mu(4)-sulfide bridged tetranuclear Cu(Z) cluster in N(2)O reductase: molecular insight into the catalytic mechanism - Chen, P.; Cabrito, I.; Moura, J. J.; Moura, I.; Solomon, E. I. (J Am Chem Soc, 2002)
Spectroscopic methods combined with density functional calculations are used to develop a detailed bonding description of the mu(4)-sulfide bridged tetranuclear Cu(Z) cluster in N(2)O reductase. The ground state of Cu(Z) has the 1Cu(II)/3Cu(I) configuration. The single electron hole dominantly resides on one Cu atom (Cu(I)) and partially delocalizes onto a second Cu atom (Cu(II)) via a Cu(I)-S-Cu(II) sigma/sigma superexchange pathway which is manifested by a Cu(II) --> Cu(I) intervalence transfer transition in absorption. The observed excited-state spectral features of Cu(Z) are dominated by the S --> Cu(I) charge-transfer transitions and Cu(I) based d-d transitions. The intensity pattern of individual S --> Cu(I) charge-transfer transitions reflects different bonding interactions of the sulfur valence orbitals with the four Cu's in the Cu(Z) cluster, which are consistent with the individual Cu-S force constants obtained from a normal coordinate analysis of the Cu(Z) resonance Raman frequencies and profiles. The Cu(I) d orbital splitting pattern correlates with its distorted T-shaped ligand field geometry and accounts for the observed low g( parallel ) value of Cu(Z) in EPR. The dominantly localized electronic structure description of the Cu(Z) site results from interactions of Cu(II) with the two additional Cu's of the cluster (Cu(III)/Cu(IV)), where the Cu-Cu electrostatic interactions lead to hole localization with no metal-metal bonding. The substrate binding edge of Cu(Z) has a dominantly oxidized Cu(I) and a dominantly reduced Cu(IV). The electronic structure description of Cu(Z) provides a strategy to overcome the reaction barrier of N(2)O reduction at this Cu(I)/Cu(IV) edge by simultaneous two-electron transfer to N(2)O in a bridged binding mode. One electron can be donated directly from Cu(IV) and the other from Cu(II) through the Cu(II)-S-Cu(I) sigma/sigma superexchange pathway. A frontier orbital scheme provides molecular insight into the catalytic mechanism of N(2)O reduction by the Cu(Z) cluster.
0002-7863 (Print)0002-7863 (Linking)Journal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.
Keywords: Catalysis; Circular Dichroism; Copper/*chemistry; Crystallography, X-Ray; Electron Spin Resonance Spectroscopy; Histidine/chemistry; Models, Molecular; Oxidoreductases/*chemistry/*metabolism; Spectrum Analysis, Raman/methods; Sulfides/chemistry; Thermodynamics

Hydrogen evolution and consumption in AOT-isooctane reverse micelles by Desulfovibrio gigas hydrogenase - Andrade, S. L. A.; Moura, J. J. G. (Enzyme and Microbial Technology, 2002)
The enzyme hydrogenase isolated from the sulphate reducing anaerobic bacterium Desulfovibrio gigas was encapsulated in reverse micelles of AOT-water-isooctane. The enzyme ability to consume molecular hydrogen was studied as a function of the micelle size (given by W-o = [H2O]/[organic solvent]). A peak of catalytic activity was obtained for W-o = 18, a micelle size theoretically fitting the heterodimeric hydrogenase molecule. At this W-o value, the recorded catalytic activity was slightly higher than in a buffer system (K-cat = 169.43 s(-1) against the buffer value of 151 s(-1)). The optimal buffer used to encapsulate the enzyme was found to be imidazole 50 mM, pH 9.0, The molecular hydrogen production activity was also tested in this reverse micelle medium. (C) 2002 Elsevier Science Inc. All lights reserved.
Times Cited: 3

Gene sequence and the 1.8 A crystal structure of the tungsten-containing formate dehydrogenase from Desulfovibrio gigas - Raaijmakers, H.; Macieira, S.; Dias, J. M.; Teixeira, S.; Bursakov, S.; Huber, R.; Moura, J. J.; Moura, I.; Romao, M. J. (Structure, 2002)
Desulfovibrio gigas formate dehydrogenase is the first representative of a tungsten-containing enzyme from a mesophile that has been structurally characterized. It is a heterodimer of 110 and 24 kDa subunits. The large subunit, homologous to E. coli FDH-H and to D. desulfuricans nitrate reductase, harbors the W site and one [4Fe-4S] center. No small subunit ortholog containing three [4Fe-4S] clusters has been reported. The structural homology with E. coli FDH-H shows that the essential residues (SeCys158, His159, and Arg407) at the active site are conserved. The active site is accessible via a positively charged tunnel, while product release may be facilitated, for H(+) by buried waters and protonable amino acids and for CO(2) through a hydrophobic channel.
0969-2126 (Print)0969-2126 (Linking)Journal ArticleResearch Support, Non-U.S. Gov't
Keywords: Amino Acid Sequence; Binding Sites; Carbon Dioxide/metabolism; Crystallography, X-Ray; Desulfovibrio/*enzymology/genetics; Electrons; Formate Dehydrogenases/*chemistry/genetics/*metabolism; Models, Molecular; Molecular Sequence Data; Protein Conformation; Protein Subunits/chemistry/metabolism; Protons; Sequence Homology, Amino Acid; Static Electricity; Structure-Activity Relationship; Tungsten/*metabolism

Zinc-substituted Desulfovibrio gigas desulforedoxins: resolving subunit degeneracy with nonsymmetric pseudocontact shifts - Goodfellow, B. J.; Nunes, S. G.; Rusnak, F.; Moura, I.; Ascenso, C.; Moura, J. J.; Volkman, B. F.; Markley, J. L. (Protein Sci, 2002)
Desulfovibrio gigas desulforedoxin (Dx) consists of two identical peptides, each containing one [Fe-4S] center per monomer. Variants with different iron and zinc metal compositions arise when desulforedoxin is produced recombinantly from Escherichia coli. The three forms of the protein, the two homodimers [Fe(III)/Fe(III)]Dx and [Zn(II)/Zn(II)]Dx, and the heterodimer [Fe(III)/Zn(II)]Dx, can be separated by ion exchange chromatography on the basis of their charge differences. Once separated, the desulforedoxins containing iron can be reduced with added dithionite. For NMR studies, different protein samples were prepared labeled with (15)N or (15)N + (13)C. Spectral assignments were determined for [Fe(II)/Fe(II)]Dx and [Fe(II)/Zn(II)]Dx from 3D (15)N TOCSY-HSQC and NOESY-HSQC data, and compared with those reported previously for [Zn(II)/Zn(II)]Dx. Assignments for the (13)C(alpha) shifts were obtained from an HNCA experiment. Comparison of (1)H-(15)N HSQC spectra of [Zn(II)/Zn(II)]Dx, [Fe(II)/Fe(II)]Dx and [Fe(II)/Zn(II)]Dx revealed that the pseudocontact shifts in [Fe(II)/Zn(II)]Dx can be decomposed into inter- and intramonomer components, which, when summed, accurately predict the observed pseudocontact shifts observed for [Fe(II)/Fe(II)]Dx. The degree of linearity observed in the pseudocontact shifts for residues >/=8.5 A from the metal center indicates that the replacement of Fe(II) by Zn(II) produces little or no change in the structure of Dx. The results suggest a general strategy for the analysis of NMR spectra of homo-oligomeric proteins in which a paramagnetic center introduced into a single subunit is used to break the magnetic symmetry and make it possible to obtain distance constraints (both pseudocontact and NOE) between subunits.
0961-8368 (Print)0961-8368 (Linking)Journal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.
Keywords: Bacterial Proteins/*metabolism; Desulfovibrio/*metabolism; Iron-Sulfur Proteins/chemistry/*metabolism; Iron/metabolism; Magnetic Resonance Spectroscopy; Zinc/*metabolism

Vanadate oligomers interaction with phosphorylated myosin - Tiago, T.; Aureliano, M.; Duarte, R. O.; Moura, J. J. G. (Inorganica Chimica Acta, 2002)
Using a myosin preparation containing endogenous myosin light-chain (LC2) kinase and phosphatase and calmodulin, i.e. near physiological ones, the interaction of vanadate oligomers with phosphorylated myosin was evaluated. Decavanadate or metavanadate solutions (2-15 mM total vanadate) did not prevent the phosphorylation state of the regulatory myosin lightchain, as observed by urea-polyacrylamide gel electrophoresis. The relative order of line broadening upon protein addition, reflecting the interaction of the vanadate oligomers with phosphorylated myosin, was V10 > V-4 > V-1 = 1 whereas, no changes were observed for monomeric vanadate. In the presence of ATP, V-1 signal was shifted upfield 2 ppm and became broadened, while V4 signal became narrowed. Moreover, a significant increase in myosin ATPase inhibition (60%) was observed when decameric vanadate species were present (1.4 mM). It is concluded that, under conditions near physiological ones, decameric vanadate differs from vanadate oligomers present in metavanadate solutions due to its strong interaction with the phosphorylated enzyme and myosin ATPase inhibition. Besides, ATP decreases the affinity of myosin for tetravanadate, induces the interaction with monomeric vanadate, whereas it does not affect decameric vanadate interaction. (C) 2002 Elsevier Science B.V. All rights reserved.
Times Cited: 4

Membrane structural changes support the involvement of mitochondria in the bile salt-induced apoptosis of rat hepatocytes - Sola, S.; Brito, M. A.; Brites, D.; Moura, J. J. G.; Rodrigues, C. M. P. (Clinical Science, 2002)
The accumulation of toxic bile salts within the hepatocyte plays a key role in organ injury during liver disease. Deoxycholate (DC) and glycochenodeoxycholate (GCDC) induce apoptosis in vitro and in vivo, perhaps through direct perturbation of mitochondrial membrane structure and function. In contrast, ursodeoxycholate (UDC) and its taurine-conjugated form (TUDC) appear to be protective. We show here that hydrophobic bile salts induced apoptosis in cultured rat hepatocytes, without modulating the expression of pro-apoptotic Bax protein, and caused cytochrome c release in isolated mitochondria. Co-incubation with UDC and TUDC prevented cell death and efflux of mitochondrial factors. Using spin-labelling techniques and EPR spectroscopy analysis of isolated rat liver mitochondria, we found significant structural changes at the membrane-water surface in mitochondria exposed to hydrophobic bile salts, including modified lipid polarity and fluidity, altered protein order and increased oxidative injury. UDC, TUDC and cyclosporin A almost completely abrogated DC- and GCDC-induced membrane perturbations. We conclude that the toxicity of hydrophobic bile salts to hepatocytes is mediated by cytochrome c release, through a mechanism associated with marked direct effects on mitochondrial membrane lipid polarity and fluidity, protein order and redox status, without modulation of pro-apoptotic Bax expression. UDC and TUDC can directly suppress disruption of mitochondrial membrane structure, which may represent an important mechanism of hepatoprotection by these bile salts.
Times Cited: 13

A contribuição da Sociologia para a formação em Engenharia [Contribution of sociology to the engineering training] - António Brandão Moniz (University Library of Munich, Germany, 2002)
This article is based on the lesson presented in the scope of academy activities in the area of Sociology (at FCT-UNL). It is intended to approach the controversies concerning the relation between technology and society (technological determinism, effect on employment, importance of the social behaviours in the definition of needs for new products and equipment), and on the most recent trends (over all, since middle of the last century) in terms of technological evolution and of its social and cultural change. Finally, this subject was dedicated to the presentation of the main factors that has lead to the development of the contribution of sociology for the training and education in engineering. Thus, one intends to acquire new elements on this area of knowledge also presented in other schools of engineering of other countries (for examples, United States and Holland), and how the theoretical beddings are been developed since the beginning of 20th century on the modalities of work organization that imply a cooperation between engineering and social sciences.
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Keywords: engineering; rationalization; socio-technical approach; sociology; theory of syst; work organization

{A contribuição da Sociologia para a formação em Engenharia [Contribution of sociology to the engineering training]} - Moniz, António B. (University Library of Munich, Germany, 2002)
This article is based on the lesson presented in the scope of academy activities in the area of Sociology (at FCT-UNL). It is intended to approach the controversies concerning the relation between technology and society (technological determinism, effect on employment, importance of the social behaviours in the definition of needs for new products and equipment), and on the most recent trends (over all, since middle of the last century) in terms of technological evolution and of its social and cultural change. Finally, this subject was dedicated to the presentation of the main factors that has lead to the development of the contribution of sociology for the training and education in engineering. Thus, one intends to acquire new elements on this area of knowledge also presented in other schools of engineering of other countries (for examples, United States and Holland), and how the theoretical beddings are been developed since the beginning of 20th century on the modalities of work organization that imply a cooperation between engineering and social sciences.
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Keywords: engineering; rationalization; socio-technical approach; sociology; theory of syst; work organization

Bilirubin directly disrupts membrane lipid polarity and fluidity, protein order, and redox status in rat mitochondria - Rodrigues, C. M.; Sola, S.; Brito, M. A.; Brites, D.; Moura, J. J. (J Hepatol, 2002)
BACKGROUND/AIMS: Unconjugated bilirubin (UCB) impairs crucial aspects of cell function and induces apoptosis in primary cultured neurones. While mechanisms of cytotoxicity begin to unfold, mitochondria appear as potential primary targets. METHODS: We used electron paramagnetic resonance spectroscopy analysis of isolated rat mitochondria to test the hypothesis that UCB physically interacts with mitochondria to induce structural membrane perturbation, leading to increased permeability, and subsequent release of apoptotic factors. RESULTS: Our data demonstrate profound changes on mitochondrial membrane properties during incubation with UCB, including modified membrane lipid polarity and fluidity (P<0.01), as well as disrupted protein mobility (P<0.001). Consistent with increased permeability, cytochrome c was released from the intermembrane space (P<0.01), perhaps uncoupling the respiratory chain and further increasing oxidative stress (P<0.01). Both ursodeoxycholate, a mitochondrial-membrane stabilising agent, and cyclosporine A, an inhibitor of the permeability transition, almost completely abrogated UCB-induced perturbation. CONCLUSIONS: UCB directly interacts with mitochondria influencing membrane lipid and protein properties, redox status, and cytochrome c content. Thus, apoptosis induced by UCB may be mediated, at least in part, by physical perturbation of the mitochondrial membrane. These novel findings should ultimately prove useful to our evolving understanding of UCB cytotoxicity.
0168-8278 (Print)0168-8278 (Linking)Journal ArticleResearch Support, Non-U.S. Gov't
Keywords: Animals; Apoptosis/physiology; Bilirubin/*metabolism/toxicity; Cyclic N-Oxides; Cytochrome c Group/metabolism; Electron Spin Resonance Spectroscopy; Hepatocytes/cytology/metabolism; Intracellular Membranes/metabolism; Lipid Bilayers/*metabolism; Membrane Fluidity/*physiology; Membrane Proteins/*metabolism; Mitochondria, Liver/*metabolism; Oxidation-Reduction; Oxidative Stress/physiology; Rats; Rats, Wistar; Reactive Oxygen Species/metabolism; Spin Labels

Perturbation of membrane dynamics in nerve cells as an early event during bilirubin-induced apoptosis - Rodrigues, C. M.; Sola, S.; Castro, R. E.; Laires, P. A.; Brites, D.; Moura, J. J. (J Lipid Res, 2002)
Increased levels of unconjugated bilirubin, the end product of heme catabolism, impair crucial aspects of nerve cell function. In previous studies, we demonstrated that bilirubin toxicity may be due to cell death by apoptosis. To characterize the sequence of events leading to neurotoxicity, we exposed developing rat brain astrocytes and neurons to unconjugated bilirubin and investigated whether changes in membrane dynamic properties can mediate apoptosis. Bilirubin induced a rapid, dose-dependent increase in apoptosis, which was nevertheless preceded by impaired mitochondrial metabolism. Using spin labels and electron paramagnetic resonance spectroscopy analysis of whole cell and isolated mitochondrial membranes exposed to bilirubin, we detected major membrane perturbation. By physically interacting with cell membranes, bilirubin induced an almost immediate increase in lipid polarity sensed at a superficial level. The enhanced membrane permeability coincided with an increase in lipid fluidity and protein mobility and was associated with significant oxidative injury to membrane lipids. In conclusion, apoptosis of nerve cells induced by bilirubin is mediated by its primary effect at physically perturbing the cell membrane. Bilirubin directly interacts with membranes influencing lipid polarity and fluidity, protein order, and redox status. These data suggest that nerve cell membranes are primary targets of bilirubin toxicity.
0022-2275 (Print)0022-2275 (Linking)Journal ArticleResearch Support, Non-U.S. Gov't
Keywords: *Apoptosis; Animals; Astrocytes/metabolism; Bilirubin/*toxicity; Cell Membrane/drug effects/*physiology; Lipid Metabolism; Lipids/chemistry; Membrane Lipids/metabolism; Membrane Proteins/metabolism; Mitochondria/metabolism; Neurons/drug effects/*physiology; Rats; Rats, Wistar

A new prenylisoflavone from Ulex jussiaei - Maximo, P; Lourenco, A.; Feio, SS; Roseiro, JC (ZEITSCHRIFT FUR NATURFORSCHUNG SECTION C-A JOURNAL OF BIOSCIENCES, 2002)
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High-resolution DOSY NMR with spins in different chemical surroundings: Influence of particle exchange - E. J. Cabrita; Berger, S; Brauer, P; Karger, J (Journal of Magnetic Resonance, 2002)
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Binding of protoporphyrin IX and metal derivatives to the active site of wild-type mouse ferrochelatase at low porphyrin-to-protein ratios - Lu, Y.; Sousa, A.; Franco, R.; Mangravita, A.; Ferreira, G. C.; Moura, I.; Shelnutt, J. A. (Biochemistry, 2002)
Resonance Raman (RR) spectroscopy is used to examine porphyrin substrate, product, and inhibitor interactions with the active site of murine ferrochelatase (EC 4.99.1.1), the terminal enzyme in the biosynthesis of heme. The enzyme catalyzes in vivo Fe2+ chelation into protoporphyrin IX to give heme. The RR spectra of native ferrochelatase show that the protein, as isolated, contains varying amounts of endogenously bound high- or low-spin ferric heme, always at much less than 1 equiv. RR data on the binding of free-base protoporphyrin IX and its metalated complexes (Fe(III), Fe(II), and Ni(II)) to active wild-type protein were obtained at varying ratios of porphyrin to protein. The binding of ferric heme, a known inhibitor of the enzyme, leads to the formation of a low-spin six-coordinate adduct. Ferrous heme, the enzyme's natural product, binds in the ferrous high-spin five-coordinate state. Ni(II) protoporphyrin, a metalloporphyrin that has a low tendency toward axial ligation, becomes distorted when bound to ferrochelatase. Similarly for free-base protoporphyrin, the natural substrate of ferrochelatase, the RR spectra of porphyrin-protein complexes reveal a saddling distortion of the porphyrin. These results corroborate and extend our previous findings that porphyrin distortion, a crucial step of the catalytic mechanism, occurs even in the absence of bound metal substrate. Moreover, RR data reveal the presence of an amino acid residue in the active site of ferrochelatase which is capable of specific axial ligation to metals.
Times Cited: 15

17O ENDOR detection of a solvent-derived Ni-(OH(x))-Fe bridge that is lost upon activation of the hydrogenase from Desulfovibrio gigas - Carepo, M.; Tierney, D. L.; Brondino, C. D.; Yang, T. C.; Pamplona, A.; Telser, J.; Moura, I.; Moura, J. J.; Hoffman, B. M. (J Am Chem Soc, 2002)
Crystallographic studies of the hydrogenases (Hases) from Desulfovibrio gigas (Dg) and Desulfovibrio vulgaris Miyazaki (DvM) have revealed heterodinuclear nickel-iron active centers in both enzymes. The structures, which represent the as-isolated (unready) Ni-A (S = (1)/(2)) enzyme state, disclose a nonprotein ligand (labeled as X) bridging the two metals. The bridging atom was suggested to be an oxygenic (O(2)(-) or OH(-)) species in Dg Hase and an inorganic sulfide in DvM Hase. To determine the nature and chemical characteristics of the Ni-X-Fe bridging ligand in Dg Hase, we have performed 35 GHz CW (17)O ENDOR measurements on the Ni-A form of the enzyme, exchanged into H(2)(17)O, on the active Ni-C (S = (1)/(2)) form prepared by H(2)-reduction of Ni-A in H(2)(17)O, and also on Ni-A formed by reoxidation of Ni-C in H(2)(17)O. In the native state of the protein (Ni-A), the bridging ligand does not exchange with the H(2)(17)O solvent. However, after a reduction/reoxidation cycle (Ni-A --> Ni-C --> Ni-A), an (17)O label is introduced at the active site, as seen by ENDOR. Detailed analysis of a 2-D field-frequency plot of ENDOR spectra taken across the EPR envelope of Ni-A((17)O) shows that the incorporated (17)O has a roughly axial hyperfine tensor, A((17)O) approximately [5, 7, 20] MHz, discloses its orientation relative to the g tensor, and also yields an estimate of the quadrupole tensor. The substantial isotropic component (a(iso)((17)O) approximately 11 MHz) of the hyperfine interaction indicates that a solvent-derived (17)O is indeed a ligand to Ni and thus that the bridging ligand X in the Ni-A state of Dg Hase is indeed an oxygenic (O(2)(-) or OH(-)) species; comparison with earlier EPR results by others indicates that the same holds for Ni-B. The small (57)Fe hyperfine coupling seen previously for Ni-A (A((57)Fe) approximately 0.9 MHz) is now shown to persist in Ni-C, A((57)Fe) approximately 0.8 MHz. However, the (17)O signal is lost upon reductive activation to the Ni-C state; reoxidation to Ni-A leads to the reappearance of the signal. Consideration of the electronic structure of the EPR-active states of the dinuclear center leads us to suggest that the oxygenic bridge in Ni-A(B) is lost in Ni-C and is re-formed from solvent upon reoxidation to Ni-A. This implies that the reductive activation to Ni-C opens Ni/Fe coordination sites which may play a central role in the enzyme's activity.
0002-7863 (Print)0002-7863 (Linking)Journal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, Non-P.H.S.
Keywords: Binding Sites; Desulfovibrio/*enzymology; Electron Spin Resonance Spectroscopy/methods; Hydrogenase/*chemistry/*metabolism; Iron/chemistry/metabolism; Models, Molecular; Nickel/chemistry/metabolism; Oxygen Isotopes

A radical approach towards indolizidine 167B - Corvo, Mc; Pereira, M. M. A. (TETRAHEDRON LETTERS, 2002)
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Electronic structure description of the mu(4)-sulfide bridged tetranuclear Cu(Z) center in N(2)O reductase - Chen, P.; DeBeer George, S.; Cabrito, I.; Antholine, W. E.; Moura, J. J.; Moura, I.; Hedman, B.; Hodgson, K. O.; Solomon, E. I. (J Am Chem Soc, 2002)
Spectroscopy coupled with density functional calculations has been used to define the spin state, oxidation states, spin distribution, and ground state wave function of the mu4-sulfide bridged tetranuclear CuZ cluster of nitrous oxide reductase. Initial insight into the electronic contribution to N2O reduction is developed, which involves a sigma superexchange pathway through the bridging sulfide.
0002-7863 (Print)0002-7863 (Linking)Journal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.
Keywords: Circular Dichroism; Copper/*chemistry; Electron Spin Resonance Spectroscopy; Molecular Structure; Oxidoreductases/*chemistry; Spectrometry, X-Ray Emission/methods; Sulfides/*chemistry

Flavonoids from Ulex airensis and Ulex europaeus ssp europaeus - Maximo, P; Lourenco, A.; Feio, SS; Roseiro, JC (JOURNAL OF NATURAL PRODUCTS, 2002)
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HR-DOSY as a new tool for the study of chemical exchange phenomena - E. J. Cabrita; Berger, S (Magnetic Resonance in Chemistry, 2002)
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Crescimento da produtividade e organização do trabalho: discussão de alguns factores [Productivity growth and organisation of work: Discussion of some factors] - António Moniz (University Library of Munich, Germany, 2002)
Recent studies continue to indicate the existence of a narrow relationship between flexible work organizations and the economic growth, in particular, Sweden and Germany. The measure of this relationship is many times the result of the value added per worker. Therefore, the causes of economic growth must be perceived from the interior of the company (work organization, technology, infrastructures, product design). On the other hand, the capacity of innovation can be perceived by the market through new products and services, and still significant changes with the introduction of new equipment and design of an efficient work organization. In this article it is analyzed the evolution of the productivity and employment levels in Portugal and other European countries, over all, during the decade of 90. An analysis for sector is made still. One verifies often that economic growth can be without employment growth. However, the growth can be obtained when if it reaches bigger added value and the efficiency can be verified when there are diminished costs for a same period of time, although that the labor productivity is also the pointer of the quality of life in a economy, therefore it represents the value produced by the work. Moreover, the total factors productivity is the measure of the technological and organizational progress (don’t includes only the technological investments). It is tried to get and to analyze the available statistics on these dimension in Portugal, concluding that Portugal presents an enterprise structure predominantly based on small and very small companies, a great number of which is market by a weak potential of adaptability, innovation and sustainability. It becomes urgent to take the non-material factors that integrate the productivity dimension, as factors of intervention for a benchmarking that allows a process of sustainable growth.
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Keywords: benchmarking; innovation; Portugal; productivity; work organisation

Hydrogen metabolism in Desulfovibrio desulfuricans strain New Jersey (NCIMB 8313)--comparative study with D. vulgaris and D. gigas species - Carepo, M.; Baptista, J. F.; Pamplona, A.; Fauque, G.; Moura, J. J.; Reis, M. A. (Anaerobe, 2002)
This article aims to study hydrogen production/consumption in Desulfovibrio (D.) desulfuricans strain New Jersey, a sulfate reducer isolated from a medium undergoing active biocorrosion and to compare its hydrogen metabolism with two other Desulfovibrio species, D. gigas and D. vulgaris Hildenborough. Hydrogen production was followed during the growth of these three bacterial species under different growth conditions: no limitation of sulfate and lactate, sulfate limitation, lactate limitation, pyruvate/sulfate medium and in the presence of molybdate. Hydrogen production/consumption by D. desulfuricans shows a behavior similar to that of D. gigas but a different one from that of D. vulgaris, which produces higher quantities of hydrogen on lactate/sulfate medium. The three species are able to increase the hydrogen production when the sulfate became limiting. Moreover, in a pyruvate/sulfate medium hydrogen production was lower than on lactate/sulfate medium. Hydrogen production by D. desulfuricans in presence of molybdate is extremely high. Hydrogenases are key enzymes on production/consumption of hydrogen in sulfate reducing organisms. The specific activity, number and cellular localization of hydrogenases vary within the three Desulfovibrio species used in this work, which could explain the differences observed on hydrogen utilization.
1075-9964 (Print)1075-9964 (Linking)Journal Article

Labour Market Policy in Portugal - António Moniz (University Library of Munich, Germany, 2002)
The Portuguese National Action Plan for Employment (NAP) is the main instrument for the labour market policy. It was adopted in 1998. The NAP transposes to the Portuguese reality the contents of such guidelines, with the adequate adjustments required by the national specificities, establishing objectives, quantified targets and action deadlines, as well as defining new programmes and measures. Therefore, the objectives of the labour market policy were focusing on the promotion of an adequate transition of the youngsters in active life, on the promotion of social and professional insertion and fight against long term unemployment and exclusion, on the improvement of basic and professional qualification of the working population in a perspective of lifelong training, namely as a way to prevent unemployment phenomena, and on the preventive management and follow-up of sectoral restructuring processes.
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Keywords: labour market; Portugal; qualification; restructuring; training; unemployment

{Crescimento da produtividade e organização do trabalho: discussão de alguns factores [Productivity growth and organisation of work: Discussion of some factors]} - António Moniz (University Library of Munich, Germany, 2002)
Recent studies continue to indicate the existence of a narrow relationship between flexible work organizations and the economic growth, in particular, Sweden and Germany. The measure of this relationship is many times the result of the value added per worker. Therefore, the causes of economic growth must be perceived from the interior of the company (work organization, technology, infrastructures, product design). On the other hand, the capacity of innovation can be perceived by the market through new products and services, and still significant changes with the introduction of new equipment and design of an efficient work organization. In this article it is analyzed the evolution of the productivity and employment levels in Portugal and other European countries, over all, during the decade of 90. An analysis for sector is made still. One verifies often that economic growth can be without employment growth. However, the growth can be obtained when if it reaches bigger added value and the efficiency can be verified when there are diminished costs for a same period of time, although that the labor productivity is also the pointer of the quality of life in a economy, therefore it represents the value produced by the work. Moreover, the total factors productivity is the measure of the technological and organizational progress (don’t includes only the technological investments). It is tried to get and to analyze the available statistics on these dimension in Portugal, concluding that Portugal presents an enterprise structure predominantly based on small and very small companies, a great number of which is market by a weak potential of adaptability, innovation and sustainability. It becomes urgent to take the non-material factors that integrate the productivity dimension, as factors of intervention for a benchmarking that allows a process of sustainable growth.
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Keywords: benchmarking; innovation; Portugal; productivity; work organisation

Labour Market Policy in Portugal - António Moniz (University Library of Munich, Germany, 2002)
The Portuguese National Action Plan for Employment (NAP) is the main instrument for the labour market policy. It was adopted in 1998. The NAP transposes to the Portuguese reality the contents of such guidelines, with the adequate adjustments required by the national specificities, establishing objectives, quantified targets and action deadlines, as well as defining new programmes and measures. Therefore, the objectives of the labour market policy were focusing on the promotion of an adequate transition of the youngsters in active life, on the promotion of social and professional insertion and fight against long term unemployment and exclusion, on the improvement of basic and professional qualification of the working population in a perspective of lifelong training, namely as a way to prevent unemployment phenomena, and on the preventive management and follow-up of sectoral restructuring processes.
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Keywords: labour market; Portugal; qualification; restructuring; training; unemployment

The Sociology of Work and the work of sociologists in Portugal - Kovács, Ilona; António Moniz (University Library of Munich, Germany, 2002)
A propose for this article is to present information on the emergence of the knowledge field of sociology of work and labor studies in Portugal. The period of 1974-1984 produced an interesting bibliography in the fields of social stratification, labor conflicts and social history. However, and since the mid-1980s, significant changes have emerged. There took place an increased theoretical diversity and also there was a major preoccupation with the development of a more professional teaching of the discipline. At this time, the first graduated specialists in Sociology appeared in the labor market since 1980, working in municipalities, industrial firms, public health institutions, schools, or even in research and development (R&D) units. The Portuguese association in this field (APSIOT) organized many scientific meetings, debates with unionists, managers and politicians, beside the regular publication of review “Organizações e Trabalho” (Organization and Work) since 1989. It started the diffusion of a professional culture of sociologists who associate science and their occupation concerning themselves not only with scientific quality, but also with technical competence and social responsibility. At the same time, one could assist to the participation of sociologists in the social and organizational molding of new technologies in order to promote alternative production systems.
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Keywords: labor studies; Portugal; sociology of work

{The Sociology of Work and the work of sociologists in Portugal} - Kovács, Ilona; António Moniz (University Library of Munich, Germany, 2002)
A propose for this article is to present information on the emergence of the knowledge field of sociology of work and labor studies in Portugal. The period of 1974-1984 produced an interesting bibliography in the fields of social stratification, labor conflicts and social history. However, and since the mid-1980s, significant changes have emerged. There took place an increased theoretical diversity and also there was a major preoccupation with the development of a more professional teaching of the discipline. At this time, the first graduated specialists in Sociology appeared in the labor market since 1980, working in municipalities, industrial firms, public health institutions, schools, or even in research and development (R&D) units. The Portuguese association in this field (APSIOT) organized many scientific meetings, debates with unionists, managers and politicians, beside the regular publication of review “Organizações e Trabalho” (Organization and Work) since 1989. It started the diffusion of a professional culture of sociologists who associate science and their occupation concerning themselves not only with scientific quality, but also with technical competence and social responsibility. At the same time, one could assist to the participation of sociologists in the social and organizational molding of new technologies in order to promote alternative production systems.
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Keywords: labor studies; Portugal; sociology of work