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2002
Bandeiras, TM, Salgueiro CA, Kletzin A, Gomes CM, Teixeira M.  2002.  Acidianus ambivalens type-II NADH dehydrogenase: genetic characterisation and identification of the flavin moiety as FMN. FEBS Letters. 531(2):273-277. AbstractWebsite

The thermoacidophilic archaeon Acidianus ambivalens contains a monomeric 47 kDa type-II NADH dehydrogenase (NDH), which contains a covalently bound flavin. In this work, by a combination of several methods, namely 31P-nuclear magnetic resonance and fluorescence spectroscopies, it is proven that this enzyme contains covalent FMN, a novelty among this family of enzymes, which were so far thought to mainly have the flavin dinucleotide form. Discrimination between several possible covalent flavin linkages was achieved by spectral and fluorescence experiments, which identified an 8α-N(1)-histidylflavin-type of linkage. Analysis of the gene-deduced amino acid sequence of type-II NDH showed no transmembranar helices and allowed the definition of putative dinucleotide and quinone binding motifs. Further, it is suggested that membrane anchoring can be achieved via amphipatic helices.

Jameson, GNL, Jin W, Krebs C, Perreira AS, Tavares P, Liu XF, Theil EC, Huynh BH.  2002.  Stoichiometric production of hydrogen peroxide and parallel formation of ferric multimers through decay of the diferric-peroxo complex, the first detectable intermediate in ferritin mineralization. Biochemistry. {41}:{13435-13443}., Number {45} Abstract

The catalytic step that initiates formation of the ferric oxy-hydroxide mineral core in the central cavity of H-type ferritin involves rapid oxidation of ferrous ion by molecular oxygen (ferroxidase reaction) at a binuclear site (ferroxidase site) found in each of the 24 subunits. Previous investigators have shown that the first detectable reaction intermediate of the ferroxidase reaction is a diferric-peroxo intermediate, F-peroxo, formed within 25 ms, which then leads to the release of H2O2 and formation of ferric mineral precursors. The stoichiometric relationship between F-peroxo, H2O2, and ferric mineral precursors, crucial to defining the reaction pathway and mechanism, has now been determined. To this end, a horseradish peroxidase-catalyzed spectrophotometric method was used as an assay for H2O2. By rapidly mixing apo M ferritin from frog, Fe2+, and O-2 and allowing the reaction to proceed for 70 ms when F-peroxo has reached its maximum accumulation, followed by spraying the reaction mixture into the H2O2 assay solution, we were able to quantitatively determine the amount of H2O2 produced during the decay of F-peroxo. The correlation between the amount of H2O2 released with the amount of F-peroxo accumulated at 70 ms determined by Mossbauer spectroscopy showed that F-peroxo decays into H2O2 with a stoichiometry of 1 F-peroxo:H2O2. When the decay of F-peroxo was monitored by rapid freeze-quench Mossbauer spectroscopy, multiple diferric mu-oxo/mu-hydroxo complexes and small polynuclear ferric clusters were found to form at rate constants identical to the decay rate of F-peroxo. This observed parallel formation of multiple products (H2O2, diferric complexes, and small polynuclear clusters) from the decay of a single precursor (F-peroxo) provides useful mechanistic insights into ferritin mineralization and demonstrates a flexible ferroxidase site.

Krings, B.  2002.  {Genderforschung und Technikentwicklung[Gender Research and Technology Development: introduction to the main topics]}. , Number 7129: University Library of Munich, Germany Abstract

Since the UN World Conference on Women in 1995 the discussion on gender has been extremely controverse. This issue of the Journal on Technology Assessment (from ITAS) presents and discuss the topic of gender research, and the relation between work and life and the changes that are occuring in the spheres of working lifes and daily lifes. Noch im Umfeld der 4. UN-Weltfrauenkonferenz in Peking 1995 wurde der Begriff gender extrem kontrovers diskutiert. Die Zeitschrift für Technikfolgenabschätzung des ITAS greift mit diesem Schwerpunkt erstmals das Thema „Genderforschung“ auf. Die Verknüpfung der beiden Themengebiete geht auf das Projekt: Wandel der Lebens- und Arbeitsbedingungen im Multimediabereich aus der Genderperspektive zurück, das zurzeit von ITAS im Auftrag des Sozialministerium Baden-Württemberg durchgeführt wird.

2001
Krings, B, Moniz A.  2001.  El desarrollo socio-cultural de la sociedad de la información: Competencia o cooperación?[Socio-cultural development of information society: competition or co-operation?], Jun , Number 6885: University Library of Munich, Germany Abstract

The results presented in this article are related to the field of investigation defined inside the European TSER project on "Information Society, Work and Generation of New Forms of Social Exclusion " (SOWING). The thematic center of the project is connected with the question of the relations that exist between the introduction of information technologies (IT) and the changes in the waged labour as well as in the organisation of work systems. The introduction of these technologies transformed specially the activities on services as well as certain branches, where great changes of the organization of work for the next future assume, which are discussed within the margin of the debate on future forms of work. The tendencies within the occupational structures indicate an individualisation of the insecurities and an opening of the occupational carreers. For these reasons, the development of the occupational carreers is more and more bound to the biographical planning. The institutionalised occupational model is changing very strongly, which in the long term will take to social and cultural changes, not only in the professional life, but also in the private life.

Moniz, A, Krings B, Van Hootegem G, Huys R.  2001.  Technological practices in the European auto industry: Exploring cases from Belgium, Germany and Portugal, Jun. , Number 5659: University Library of Munich, Germany Abstract

The relation between work organisation and technological practices in auto industry is analysed in this article. The concept of “technological practice” in this sector is used to describe the specific ways of embedding information and communication technology applications into the organizational forms and cultural patterns. This concept was developed with the Sowing project (TSER, DG XII) and that approach included either the shop floor co-operation up to the regionally based networks of companies and supporting institutions. The authors studied different sectors in the automotive firms of different European countries (Germany, Belgium and Portugal): shopfloor and production lines, design and management and the local inter-relationships. It was underlined some evidencies of the different alternatives in terms of technological practices for the same sector. Much of the litterature try to disseminate an idea of a single (and optimum) organisational model for the same type of product. And here, even with the same type of technology, and of product (medium-high range), one can find different models, different cultures, different ways of organising the industrial structure (firms, regional institutions, R&D centres) in the same sector (auto industry).

Krings, B, Moniz A.  2001.  {El desarrollo socio-cultural de la sociedad de la información: Competencia o cooperación?[Socio-cultural development of information society: competition or co-operation?]}, Jun , Number 6885: University Library of Munich, Germany Abstract

The results presented in this article are related to the field of investigation defined inside the European TSER project on "Information Society, Work and Generation of New Forms of Social Exclusion " (SOWING). The thematic center of the project is connected with the question of the relations that exist between the introduction of information technologies (IT) and the changes in the waged labour as well as in the organisation of work systems. The introduction of these technologies transformed specially the activities on services as well as certain branches, where great changes of the organization of work for the next future assume, which are discussed within the margin of the debate on future forms of work. The tendencies within the occupational structures indicate an individualisation of the insecurities and an opening of the occupational carreers. For these reasons, the development of the occupational carreers is more and more bound to the biographical planning. The institutionalised occupational model is changing very strongly, which in the long term will take to social and cultural changes, not only in the professional life, but also in the private life.

Krings, B, Moniz A.  2001.  {El desarrollo socio-cultural de la sociedad de la información: Competencia o cooperación?[Socio-cultural development of information society: competition or co-operation?]}, Jun , Number 6885: University Library of Munich, Germany Abstract

The results presented in this article are related to the field of investigation defined inside the European TSER project on "Information Society, Work and Generation of New Forms of Social Exclusion " (SOWING). The thematic center of the project is connected with the question of the relations that exist between the introduction of information technologies (IT) and the changes in the waged labour as well as in the organisation of work systems. The introduction of these technologies transformed specially the activities on services as well as certain branches, where great changes of the organization of work for the next future assume, which are discussed within the margin of the debate on future forms of work. The tendencies within the occupational structures indicate an individualisation of the insecurities and an opening of the occupational carreers. For these reasons, the development of the occupational carreers is more and more bound to the biographical planning. The institutionalised occupational model is changing very strongly, which in the long term will take to social and cultural changes, not only in the professional life, but also in the private life.

Moniz, A, Krings B, Van Hootegem G, Huys R.  2001.  {Technological practices in the European auto industry: Exploring cases from Belgium, Germany and Portugal}, Jun. , Number 5659: University Library of Munich, Germany Abstract

The relation between work organisation and technological practices in auto industry is analysed in this article. The concept of “technological practice” in this sector is used to describe the specific ways of embedding information and communication technology applications into the organizational forms and cultural patterns. This concept was developed with the Sowing project (TSER, DG XII) and that approach included either the shop floor co-operation up to the regionally based networks of companies and supporting institutions. The authors studied different sectors in the automotive firms of different European countries (Germany, Belgium and Portugal): shopfloor and production lines, design and management and the local inter-relationships. It was underlined some evidencies of the different alternatives in terms of technological practices for the same sector. Much of the litterature try to disseminate an idea of a single (and optimum) organisational model for the same type of product. And here, even with the same type of technology, and of product (medium-high range), one can find different models, different cultures, different ways of organising the industrial structure (firms, regional institutions, R&D centres) in the same sector (auto industry).

Baldwin, J, Voegtli WC, Khidekel N, Moenne-Loccoz P, Krebs C, Pereira AS, Ley BA, Huynh BH, Loehr TM, Riggs-Gelasco PJ, Rosenzweig AC, Bollinger JM.  2001.  Rational reprogramming of the R2 subunit of Escherichia coli ribonucleotide reductase into a self-hydroxylating monooxygenase. Journal Of The American Chemical Society. {123}:{7017-7030}., Number {29}, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA: AMER CHEMICAL SOC Abstract

The outcome of O-2 activation at the diiron(II) cluster in the R2 subunit of Escherichia coli (class I) ribonucleotide reductase has been rationally altered from the normal tyrosyl radical (Y122)(1) production to self-hydroxylation of a phenylalanine side-chain by two amino acid substitutions that leave intact the (histidine)(2)-(carboxylate)(4) ligand set characteristic of the diiron-carboxylate family. Iron ligand Asp (D) 84 was replaced with Glu (E), the amino acid found in the cognate position of the structurally similar diiron-carboxylate protein, methane monooxygenase hydroxylase (MMOH). We previously showed that this substitution allows accumulation of a mu -1,2-peroxodiiron(III) intermediate,(2 3) which does not accumulate in the wild-type (wt) protein and is probably a structural homologue of intermediate P (H-peroxo) in O-2 activation by MMOH.(4) In addition, the near-surface residue Trp (W) 48 was replaced with Phe (F), blocking transfer of the ``extra'' electron that occurs in wt R2 during formation of the formally Fe(LII)Fe(IV) cluster X.(5-7) Decay of the mu1,2-peroxodiiron(III) complex in R2-W38F/D84E gives an initial brown product, which contains very little YI22(.) and which converts very slowly (t(1/2) similar to 7 h) upon incubation at 0 degreesC to an intensely purple final product. X-ray crystallographic analysis of the purple product indicates that F208 has undergone epsilon -hydroxylation and the resulting phenol has shifted significantly to become st ligand to Fe2 of the diiron cluster. Resonance Raman (RR) spectra of the purple product generated with O-16(2) or O-18(2) show appropriate isotopic sensitivity in bands assigned to O-phenyl and Fe-O-phenyl vibrational modes, confirming that the oxygen of the Fe(III)-phenolate species is derived from Or. Chemical analysis, experiments involving interception of the hydroxylating intermediate with exogenous reductant, and Mossbauer and EXAFS characterization of the brown and purple species establish that F208 hydroxylation occurs during decay of the peroxo complex and formation of the initial brown product. The slow transition to the purple Fe(LII)-phenolate species is ascribed to a ligand rearrangement in which mu -O2- is lost and the F208-derived phenolate coordinates. The reprogramming to F208 monooxygenase requires both amino acid substitutions, as very little epsilon -hydroxyphenylalanine is formed and pathways leading to Y122(.) formation predominate in both R2-D84E and R2-W48F(2-7).

Moniz, A, Krings B, Van Hootegem G, Huys R.  2001.  {Technological practices in the European auto industry: Exploring cases from Belgium, Germany and Portugal}. , Number 5659: University Library of Munich, Germany Abstract

The relation between work organisation and technological practices in auto industry is analysed in this article. The concept of “technological practice” in this sector is used to describe the specific ways of embedding information and communication technology applications into the organizational forms and cultural patterns. This concept was developed with the Sowing project (TSER, DG XII) and that approach included either the shop floor co-operation up to the regionally based networks of companies and supporting institutions. The authors studied different sectors in the automotive firms of different European countries (Germany, Belgium and Portugal): shopfloor and production lines, design and management and the local inter-relationships. It was underlined some evidencies of the different alternatives in terms of technological practices for the same sector. Much of the litterature try to disseminate an idea of a single (and optimum) organisational model for the same type of product. And here, even with the same type of technology, and of product (medium-high range), one can find different models, different cultures, different ways of organising the industrial structure (firms, regional institutions, R&D centres) in the same sector (auto industry).

2000
Kapur, GS, Cabrita EJ, Berger S.  2000.  The qualitative probing of hydrogen bond strength by diffusion-ordered NMR spectroscopy, SEP 9 2000. Tetrahedron Letters. 41:7181-7185., Number 37 Abstract

n/a

Wengenack, NL, Lopes H, Kennedy MJ, Tavares P, Pereira AS, Moura I, Moura JJ, Rusnak F.  2000.  Redox potential measurements of the Mycobacterium tuberculosis heme protein KatG and the isoniazid-resistant enzyme KatG(S315T): insights into isoniazid activation, Sep 19. Biochemistry. 39:11508-13., Number 37 AbstractWebsite

Mycobacterium tuberculosis KatG is a multifunctional heme enzyme responsible for activation of the antibiotic isoniazid. A KatG(S315T) point mutation is found in >50% of isoniazid-resistant clinical isolates. Since isoniazid activation is thought to involve an oxidation reaction, the redox potential of KatG was determined using cyclic voltammetry, square wave voltammetry, and spectroelectrochemical titrations. Isoniazid activation may proceed via a cytochrome P450-like mechanism. Therefore, the possibility that substrate binding by KatG leads to an increase in the heme redox potential and the possibility that KatG(S315T) confers isoniazid resistance by altering the redox potential were examined. Effects of the heme spin state on the reduction potentials of KatG and KatG(S315T) were also determined. Assessment of the Fe(3+)/Fe(2+) couple gave a midpoint potential of ca. -50 mV for both KatG and KatG(S315T). In contrast to cytochrome P450s, addition of substrate had no significant effect on either the KatG or KatG(S315T) redox potential. Conversion of the heme to a low-spin configuration resulted in a -150 to -200 mV shift of the KatG and KatG(S315T) redox potentials. These results suggest that isoniazid resistance conferred by KatG(S315T) is not mediated through changes in the heme redox potential. The redox potentials of isoniazid were also determined using cyclic and square wave voltammetry, and the results provide evidence that the ferric KatG and KatG(S315T) midpoint potentials are too low to promote isoniazid oxidation without formation of a high-valent enzyme intermediate such as compounds I and II or oxyferrous KatG.

Jovanovic, T, Ascenso C, Hazlett KR, Sikkink R, Krebs C, Litwiller R, Benson LM, Moura I, Moura JJ, Radolf JD, Huynh BH, Naylor S, Rusnak F.  2000.  Neelaredoxin, an iron-binding protein from the syphilis spirochete, Treponema pallidum, is a superoxide reductase, Sep 15. J Biol Chem. 275:28439-48., Number 37 AbstractWebsite

Treponema pallidum, the causative agent of venereal syphilis, is a microaerophilic obligate pathogen of humans. As it disseminates hematogenously and invades a wide range of tissues, T. pallidum presumably must tolerate substantial oxidative stress. Analysis of the T. pallidum genome indicates that the syphilis spirochete lacks most of the iron-binding proteins present in many other bacterial pathogens, including the oxidative defense enzymes superoxide dismutase, catalase, and peroxidase, but does possess an orthologue (TP0823) for neelaredoxin, an enzyme of hyperthermophilic and sulfate-reducing anaerobes shown to possess superoxide reductase activity. To analyze the potential role of neelaredoxin in treponemal oxidative defense, we examined the biochemical, spectroscopic, and antioxidant properties of recombinant T. pallidum neelaredoxin. Neelaredoxin was shown to be expressed in T. pallidum by reverse transcriptase-polymerase chain reaction and Western blot analysis. Recombinant neelaredoxin is a 26-kDa alpha(2) homodimer containing, on average, 0.7 iron atoms/subunit. Mossbauer and EPR analysis of the purified protein indicates that the iron atom exists as a mononuclear center in a mixture of high spin ferrous and ferric oxidation states. The fully oxidized form, obtained by the addition of K(3)(Fe(CN)(6)), exhibits an optical spectrum with absorbances at 280, 320, and 656 nm; the last feature is responsible for the protein's blue color, which disappears upon ascorbate reduction. The fully oxidized protein has a A(280)/A(656) ratio of 10.3. Enzymatic studies revealed that T. pallidum neelaredoxin is able to catalyze a redox equilibrium between superoxide and hydrogen peroxide, a result consistent with it being a superoxide reductase. This finding, the first description of a T. pallidum iron-binding protein, indicates that the syphilis spirochete copes with oxidative stress via a primitive mechanism, which, thus far, has not been described in pathogenic bacteria.

Morelli, X, Dolla A, Czjzek M, Palma PN, Blasco F, Krippahl L, Moura JJ, Guerlesquin F.  2000.  Heteronuclear NMR and soft docking: an experimental approach for a structural model of the cytochrome c553-ferredoxin complex, Mar 14. Biochemistry. 39:2530-7., Number 10 AbstractWebsite

The combination of docking algorithms with NMR data has been developed extensively for the studies of protein-ligand interactions. However, to extend this development for the studies of protein-protein interactions, the intermolecular NOE constraints, which are needed, are more difficult to access. In the present work, we describe a new approach that combines an ab initio docking calculation and the mapping of an interaction site using chemical shift variation analysis. The cytochrome c553-ferredoxin complex is used as a model of numerous electron-transfer complexes. The 15N-labeling of both molecules has been obtained, and the mapping of the interacting site on each partner, respectively, has been done using HSQC experiments. 1H and 15N chemical shift analysis defines the area of both molecules involved in the recognition interface. Models of the complex were generated by an ab initio docking software, the BiGGER program (bimolecular complex generation with global evaluation and ranking). This program generates a population of protein-protein docked geometries ranked by a scoring function, combining relevant stabilization parameters such as geometric complementarity surfaces, electrostatic interactions, desolvation energy, and pairwise affinities of amino acid side chains. We have implemented a new module that includes experimental input (here, NMR mapping of the interacting site) as a filter to select the accurate models. Final structures were energy minimized using the X-PLOR software and then analyzed. The best solution has an interface area (1037.4 A2) falling close to the range of generally observed recognition interfaces, with a distance of 10.0 A between the redox centers.

Palma, PN, Krippahl L, Wampler JE, Moura JJ.  2000.  BiGGER: a new (soft) docking algorithm for predicting protein interactions, Jun 1. Proteins. 39:372-84., Number 4 AbstractWebsite

A new computationally efficient and automated "soft docking" algorithm is described to assist the prediction of the mode of binding between two proteins, using the three-dimensional structures of the unbound molecules. The method is implemented in a software package called BiGGER (Bimolecular Complex Generation with Global Evaluation and Ranking) and works in two sequential steps: first, the complete 6-dimensional binding spaces of both molecules is systematically searched. A population of candidate protein-protein docked geometries is thus generated and selected on the basis of the geometric complementarity and amino acid pairwise affinities between the two molecular surfaces. Most of the conformational changes observed during protein association are treated in an implicit way and test results are equally satisfactory, regardless of starting from the bound or the unbound forms of known structures of the interacting proteins. In contrast to other methods, the entire molecular surfaces are searched during the simulation, using absolutely no additional information regarding the binding sites. In a second step, an interaction scoring function is used to rank the putative docked structures. The function incorporates interaction terms that are thought to be relevant to the stabilization of protein complexes. These include: geometric complementarity of the surfaces, explicit electrostatic interactions, desolvation energy, and pairwise propensities of the amino acid side chains to contact across the molecular interface. The relative functional contribution of each of these interaction terms to the global scoring function has been empirically adjusted through a neural network optimizer using a learning set of 25 protein-protein complexes of known crystallographic structures. In 22 out of 25 protein-protein complexes tested, near-native docked geometries were found with C(alpha) RMS deviations < or =4.0 A from the experimental structures, of which 14 were found within the 20 top ranking solutions. The program works on widely available personal computers and takes 2 to 8 hours of CPU time to run any of the docking tests herein presented. Finally, the value and limitations of the method for the study of macromolecular interactions, not yet revealed by experimental techniques, are discussed.

Moniz, A, Kovács I, Vicente D, Ramos AR.  2000.  Fisheries Development and Fisheries Dependent Communities in Portugal: Socio-Economic Change and Strategic Planning, Feb. , Number 7154: University Library of Munich, Germany Abstract

The socio-economic subsystem encompassing fisheries may be defined as including not only the harvesting sector but also several related activities occurring both upstream (shipbuilding, gear manufacture) and downstream (processing, distribution and trade). But these closely interrelated economic activities can also be set within a much broader system which would include the ecological, institutional and political influences which frame economic behaviour. The value of this broader conceptualisation is that it treats fisheries not as an isolated and independent economic activity but as part of a more holistic and complex system. This broader perspective is of particular significance when attempting to examine the concept of regional dependence. The socio-economic subsystem for fisheries is dominated by small and medium sized enterprises (SMEs). And Peniche emerges as one of Portugal’s most important fishing ports whether measured in terms of the volume of landings or the total numbers of fishermen. It also has one of the highest levels of fisheries dependence of all coastal municipalities in Portugal with over 20% of its workforce currently engaged in fisheries related employment, faces a daunting and uncertain future. The social fabric of fisheries dependent communities also suffers serious damage; once again, the technocratic approach to management has no solutions to offer. It is essential, therefore, to turn away from the existing approach and to develop instead new forms of intervention; in short, to provide a new vision. This implies change not only to the policy process but also in the attitudes of the social actors and in the preoccupations of fisheries related research. An integrated approach is required based on participative action and the development of an integrated information network.

Moniz, A, Kovács I, Vicente D, Ramos AR.  2000.  {Fisheries Development and Fisheries Dependent Communities in Portugal: Socio-Economic Change and Strategic Planning}, Feb. , Number 7154: University Library of Munich, Germany Abstract

The socio-economic subsystem encompassing fisheries may be defined as including not only the harvesting sector but also several related activities occurring both upstream (shipbuilding, gear manufacture) and downstream (processing, distribution and trade). But these closely interrelated economic activities can also be set within a much broader system which would include the ecological, institutional and political influences which frame economic behaviour. The value of this broader conceptualisation is that it treats fisheries not as an isolated and independent economic activity but as part of a more holistic and complex system. This broader perspective is of particular significance when attempting to examine the concept of regional dependence. The socio-economic subsystem for fisheries is dominated by small and medium sized enterprises (SMEs). And Peniche emerges as one of Portugal’s most important fishing ports whether measured in terms of the volume of landings or the total numbers of fishermen. It also has one of the highest levels of fisheries dependence of all coastal municipalities in Portugal with over 20% of its workforce currently engaged in fisheries related employment, faces a daunting and uncertain future. The social fabric of fisheries dependent communities also suffers serious damage; once again, the technocratic approach to management has no solutions to offer. It is essential, therefore, to turn away from the existing approach and to develop instead new forms of intervention; in short, to provide a new vision. This implies change not only to the policy process but also in the attitudes of the social actors and in the preoccupations of fisheries related research. An integrated approach is required based on participative action and the development of an integrated information network.

Moniz, A, Kovács I.  2000.  Conditions Of Inter-Firm Co-Operation In A Virtual Enterprise Concept : The Case Of Automotive Sector In Portugal. , Number 5658: University Library of Munich, Germany Abstract

One can assist to significant changes in the organisation of manufacturing systems during the last years. Lean production, network enterprise or the virtual enterprises are reference concepts of the re-organisation of manufacturing systems. Some authors mention a new enterprise paradigm, of generalisation of intelligent manufacture, organised in networks and assisted by information and communication technologies. The first part of the paper develops a critical approach to the illusion connected to these concepts, calling the attention to the diversity of the type of relationships among firms. If virtual enterprises (VE) are networks of firms with intensive usage of ICT, one can verify a predominance of a technicist perspective. This one considers that the development of VEs is a technological problem, of development and management of information systems, and of entrepreneurial share of different databases. Sociology can be useful, even fundamental in an anthropocentric approach. The last part of the paper is on the Portuguese situation in the automobile sector, approaching the types of entrepreneurial organisation.

Wengenack, NL, Lopes H, Kennedy MJ, Tavares P, Pereira AS, Moura I, Moura JJG, Rusnak F.  2000.  Redox potential measurements of the Mycobacterium tuberculosis heme protein KatG and the isoniazid-resistant enzyme KatG(S315T): Insights into isoniazid activation. Biochemistry. {39}:{11508-11513}., Number {37} Abstract

Mycobacterium tuberculosis KatG is a multifunctional heme enzyme responsible for activation of the antibiotic isoniazid. A KatG(S315T) point mutation is found in >50% of isoniazid-resistant clinical isolates. Since isoniazid activation is thought to involve an oxidation reaction, the redox potential of KatG was determined using cyclic voltammetry, square wave voltammetry, and spectroelectrochemical titrations. Isoniazid activation may proceed via a cytochrome P450-like mechanism. Therefore, the possibility that substrate binding by KatG leads to an increase in the heme redox potential and the possibility that KatG(S315T) confers isoniazid resistance by altering the redox potential were examined. Effects of the heme spin state on the reduction potentials of KatG and KatG(S315T) were also determined. Assessment of the Fe3+/Fe2+ couple gave a midpoint potential of ca. -50 mV for both KatG and KatG(S315T). In contrast to cytochrome P450s, addition of substrate had no significant effect on either the KatG or KatG(S315T) redox potential. Conversion of the heme to a low-spin configuration resulted in a -150 to -200 mV shift of the KatG and KatG(S315T) redox potentials. These results suggest that isoniazid resistance conferred by KatG(S315T) is not mediated through changes in the heme redox potential. The redox potentials of isoniazid were also determined using cyclic and square wave voltammetry, and the results provide evidence that the ferric KatG and KatG(S315T) midpoint potentials are too low to promote isoniazid oxidation without formation of a high-valent enzyme intermediate such as compounds I and IT or oxyferrous KatG.

Moniz, A, Kovács I.  2000.  {Conditions Of Inter-Firm Co-Operation In A Virtual Enterprise Concept : The Case Of Automotive Sector In Portugal}. , Number 5658: University Library of Munich, Germany Abstract

One can assist to significant changes in the organisation of manufacturing systems during the last years. Lean production, network enterprise or the virtual enterprises are reference concepts of the re-organisation of manufacturing systems. Some authors mention a new enterprise paradigm, of generalisation of intelligent manufacture, organised in networks and assisted by information and communication technologies. The first part of the paper develops a critical approach to the illusion connected to these concepts, calling the attention to the diversity of the type of relationships among firms. If virtual enterprises (VE) are networks of firms with intensive usage of ICT, one can verify a predominance of a technicist perspective. This one considers that the development of VEs is a technological problem, of development and management of information systems, and of entrepreneurial share of different databases. Sociology can be useful, even fundamental in an anthropocentric approach. The last part of the paper is on the Portuguese situation in the automobile sector, approaching the types of entrepreneurial organisation.

1999
Pereira, AS, Tavares P, Krebs C, Huynh BH, Rusnak F, Moura I, Moura JJ.  1999.  Biochemical and spectroscopic characterization of overexpressed fuscoredoxin from Escherichia coli, Jun 24. Biochem Biophys Res Commun. 260:209-15., Number 1 AbstractWebsite

Fuscoredoxin is a unique iron containing protein of yet unknown function originally discovered in the sulfate reducers of the genus Desulfovibrio. It contains two iron-sulfur clusters: a cubane [4Fe-4S] and a mixed oxo- and sulfido-bridged 4Fe cluster of unprecedented structure. The recent determination of the genomic sequence of Escherichia coli (E. coli) has revealed a homologue of fuscoredoxin in this facultative microbe. The presence of this gene in E. coli raises interesting questions regarding the function of fuscoredoxin and whether this gene represents a structural homologue of the better-characterized Desulfovibrio proteins. In order to explore the latter, an overexpression system for the E. coli fuscoredoxin gene was devised. The gene was cloned from genomic DNA by use of the polymerase chain reaction into the expression vector pT7-7 and overexpressed in E. coli BL21(DE3) cells. After two chromatographic steps a good yield of recombinant protein was obtained (approximately 4 mg of pure protein per liter of culture). The purified protein exhibits an optical spectrum characteristic of the homologue from D. desulfuricans, indicating that cofactor assembly was accomplished. Iron analysis indicated that the protein contains circa 8 iron atoms/molecule which were shown by EPR and Mossbauer spectroscopies to be present as two multinuclear clusters, albeit with slightly altered spectroscopic features. A comparison of the primary sequences of fuscoredoxins is presented and differences on cluster coordination modes are discussed on the light of the spectroscopic data.

Kuhlmann, S, Boekholt P, Georghiou L, Guy K, Heraud J-A, Laredo P, Lemola T, Loveridge D, Luukkonen T, Moniz A, Polt W, Ri.  1999.  Improving Distributed Intelligence in Complex Innovation Systems, Jun. , Number 6426: University Library of Munich, Germany Abstract

Science and technology (S&T) are considered to be a central source, or at least a basic medium, of societal and industrial innovation, while innovation is conceived to basically feed the regeneration of our welfare. The suppliers of S&T in Europe as well as the users of their „products“, are confronted with a number of challenges today. We want to stress here that it was not the primary goal of our Advanced Science & Technology Policy Planning (ASTPP) Network to come up with proposals how the strategic character of European S&T policies could be strengthened. The ASTPP-network instead focuses on one aspect: the provision of strategic intelligence necessary to identify and develop strategic choices. The underlying hypothesis is that the existing body of experiences with technology foresight, technology assessment and S/T policy evaluation provides a basis for the development of an advanced S&T policy „planning“ approach by trying to enhance, interlink or even integrate the growing, but still dispersed experience in these three areas of intelligence. By „intelligent“ we mean that the inter-relatedness of S&T, industrial efforts, societal needs and political interventions becomes more transparent so that interactive collaboration between them will be facilitated.

Kuhlmann, S, Boekholt P, Georghiou L, Guy K, Heraud J-A, Laredo P, Lemola T, Loveridge D, Luukkonen T, Moniz A, Polt W, Rip.  1999.  {Improving Distributed Intelligence in Complex Innovation Systems}, Jun. , Number 6426: University Library of Munich, Germany Abstract

Science and technology (S&T) are considered to be a central source, or at least a basic medium, of societal and industrial innovation, while innovation is conceived to basically feed the regeneration of our welfare. The suppliers of S&T in Europe as well as the users of their „products“, are confronted with a number of challenges today. We want to stress here that it was not the primary goal of our Advanced Science & Technology Policy Planning (ASTPP) Network to come up with proposals how the strategic character of European S&T policies could be strengthened. The ASTPP-network instead focuses on one aspect: the provision of strategic intelligence necessary to identify and develop strategic choices. The underlying hypothesis is that the existing body of experiences with technology foresight, technology assessment and S/T policy evaluation provides a basis for the development of an advanced S&T policy „planning“ approach by trying to enhance, interlink or even integrate the growing, but still dispersed experience in these three areas of intelligence. By „intelligent“ we mean that the inter-relatedness of S&T, industrial efforts, societal needs and political interventions becomes more transparent so that interactive collaboration between them will be facilitated.

Pettigrew, GW, Prazeres S, Costa C, Palma N, Krippahl L, Moura I, Moura JJ.  1999.  The structure of an electron transfer complex containing a cytochrome c and a peroxidase, Apr 16. J Biol Chem. 274:11383-9., Number 16 AbstractWebsite

Efficient biological electron transfer may require a fluid association of redox partners. Two noncrystallographic methods (a new molecular docking program and 1H NMR spectroscopy) have been used to study the electron transfer complex formed between the cytochrome c peroxidase (CCP) of Paracoccus denitrificans and cytochromes c. For the natural redox partner, cytochrome c550, the results are consistent with a complex in which the heme of a single cytochrome lies above the exposed electron-transferring heme of the peroxidase. In contrast, two molecules of the nonphysiological but kinetically competent horse cytochrome bind between the two hemes of the peroxidase. These dramatically different patterns are consistent with a redox active surface on the peroxidase that may accommodate more than one cytochrome and allow lateral mobility.

Kuhn, FE, Goncalves IS, Lopes AD, Lopes JP, Romao CC, Wachter W, Mink J, Hajba L, Parola AJ, Pina F, Sotomayor J.  1999.  Tetracarboxylatodirhenium complexes linked by axial cyano bridges to metalpentacarbonyl ligands - Synthesis and characterization, 1999. European Journal of Inorganic Chemistry. :295-301. AbstractWebsite

Reaction of Re-2{mu-O2CC(CH3)(3)}(4)Cl-2 with [(CO)(5)M-CN]Na (M = Cr, Mo, W) leads to tetranuclear complexes of formula Re-2{mu-O2CC(CH3)(3)}(4)[-NC-M(CO)(5)](2) (M = Cr, Mo, W). These complexes were characterized by H-1-, C-13-, and Mo-95-NMR, IR and Raman spectroscopy, elemental analysis and examined by cyclic voltammetry. The applied methods show the donor capabilities of the [(CO)(5)M-CN](-) ligands which shift electron density towards the Re centers weakening the Re-Re quadruple bond. The Re-Re bond lengths and the v(Re-Re) force constants are estimated based on the FT-IR and Raman examinations. Photochemical examinations and TG/MS experiments have also been conducted. The latter methods shows that the product complexes decompose around 100 degrees C, by first loosing their carbonyl substituents; as do the Cr, Mo, W precursor compounds. The dirhenium tetrapivalate unit decomposes only at higher temperatures in a distinct second step.