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Characterization of a 7Fe ferredoxin isolated from the marine denitrifier Pseudomonas nautica strain 617: spectroscopic and electrochemical studies, Macedo, A. L., Besson S., Moreno C., Fauque G., Moura J. J., and Moura I. , Biochem Biophys Res Commun, Dec 13, Volume 229, Number 2, p.524-30, (1996) AbstractWebsite

A 7Fe ferredoxin, isolated from the marine denitrifier Pseudomonas nautica strain 617, was characterized. The NH2-terminal sequence analysis, performed until residue number 56, shows a high similarity with the 7Fe ferredoxins isolated from Azotobacter vinelandii, Pseudomonas putida, and Pseudomonas stutzeri. EPR and NMR spectroscopies identify the presence of both [3Fe-4S] and [4Fe-4S] clusters, with cysteinyl coordination. The electrochemical studies on [Fe-S] clusters show that a fast diffusion-dominated electron transfer, promoted by Mg(II), takes place between the ferredoxin and the glassy carbon electrode. Square wave voltammetry studies gave access to the electrosynthesis of a 4Fe center formed within the [3Fe-4S] core. The [3Fe-4S] cluster exhibited two reduction potentials at -175 and -680 +/- 10 mV and the [4Fe-4S] cluster was characterized by an unusually low reduction potential of -715 +/- 10 mV, at pH 7.6

Characterization of D. desulfuricans (ATCC 27774) [NiFe] hydrogenase EPR and redox properties of the native and the dihydrogen reacted states, Franco, R., Moura I., Legall J., Peck, H. D. Jr., Huynh B. H., and Moura J. J. , Biochim Biophys Acta, Oct 4, Volume 1144, Number 3, p.302-8, (1993) AbstractWebsite

Redox intermediates of D. desulfuricans ATCC 27774 [NiFe] hydrogenase were generated under dihydrogen. Detailed redox titrations, coupled to EPR measurements, give access to the mid-point redox potentials of the iron-sulfur centers and of the Nickel-B signal that represents the ready form of the enzyme. The interaction between the dihydrogen molecule and the nickel centre was probed by the observation of an isotopic effect on the EPR signals detected in turnover conditions, by comparison of the H2O/H2 and D2O/D2-reacted samples.

Characterization Of Electron-Transfer Proteins From The Nitrogen-Fixing Sulfate-Reducing Bacterium Desulfovibrio-Desulfuricans Berre-Eau, Fauque, G., Moura I., Xavier A. V., Galliano N., Moura J. J. G., and Legall J. , Biochemical Society Transactions, Dec, Volume 15, Number 6, p.1049-1050, (1987) AbstractWebsite
Characterization of recombinant Desulfovibrio gigas ferredoxin, Rodrigues, P., Graca F., Macedo A. L., Moura I., and Moura J. J. , Biochem Biophys Res Commun, Nov 30, Volume 289, Number 2, p.630-3, (2001) AbstractWebsite

Dg ferredoxin gene was cloned using the polymerase chain reaction (PCR), inserted into vector pT7-7, and overexpressed in Escherichia coli (E. coli) grown in aerobic media. The recombinant protein is a dimer and contains a [3Fe-4S] cluster per monomer. EPR and (1)H NMR data of recombinant and wild-type protein are compared.

Characterization of representative enzymes from a sulfate reducing bacterium implicated in the corrosion of steel, Pereira, A. S., Franco R., Feio M. J., Pinto C., Lampreia J., Reis M. A., Calvete J., Moura I., Beech I., Lino A. R., and Moura J. J. , Biochem Biophys Res Commun, Apr 16, Volume 221, Number 2, p.414-21, (1996) AbstractWebsite

This communication reports the isolation, purification and characterization of key enzymes involved in dissimilatory sulfate reduction of a sulfate reducing bacterium classified as Desulfovibrio desulfuricans subspecies desulfuricans New Jersey (NCIMB 8313) (Ddd NJ). The chosen strain, originally recovered from a corroding cast iron heat exchanger, was grown in large scale batch cultures. Physico-chemical and spectroscopic studies of the purified enzymes were carried out. These analyses revealed a high degree of similarity between proteins isolated from the DddNJ strain and the homologous proteins obtained from Desulfomicrobium baculatus Norway 4. In view of the results obtained, taxonomic reclassification of Desulfovibrio desulfuricans subspecies desulfuricans New Jersey (NCIMB 8313) into Desulfomicrobium baculatus (New Jersey) is proposed.

Characterization of the cytochrome system of a nitrogen-fixing strain of a sulfate-reducing bacterium: Desulfovibrio desulfuricans strain Berre-Eau, Moura, I., Fauque G., Legall J., Xavier A. V., and Moura J. J. , Eur J Biochem, Feb 2, Volume 162, Number 3, p.547-54, (1987) AbstractWebsite

Two c-type cytochromes were purified and characterized by electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) spectroscopic techniques, from the sulfate-reducer nitrogen-fixing organism, Desulfovibrio desulfuricans strain Berre-Eau (NCIB 8387). The purification procedures included several chromatographic steps on alumina, carboxymethylcellulose and gel filtration. A tetrahaem and a monohaem cytochrome were identified. The multihaem cytochrome has visible, EPR and NMR spectra with general properties similar to other low-potential bis-histidinyl axially bound haem proteins, belonging to the class of tetrahaem cytochrome c3 isolated from other Desulfovibrio species. The monohaem cytochrome c553 is ascorbate-reducible and its EPR and NMR data are characteristic of a cytochrome with methionine-histidine ligation. Their properties are compared with other homologous proteins isolated from sulfate-reducing bacteria.

Characterization of the Dihemic Cytochrome C549 from the Marine Denitrifying Bacterium Pseudomonas nautica 617, Saraiva, L. M., Besson S., Fauque G., and Moura I. , Biochemical and Biophysical Research Communications, Volume 199, Number 3, p.1289-1296, (1994) AbstractWebsite
Characterization of the interaction between PQQ and heme c in the quinohemoprotein ethanol dehydrogenase from Comamonas testosteroni, de Jong, G. A., Caldeira J., Sun J., Jongejan J. A., de Vries S., Loehr T. M., Moura I., Moura J. J., and Duine J. A. , Biochemistry, Jul 25, Volume 34, Number 29, p.9451-8, (1995) AbstractWebsite

Quinohemoprotein ethanol dehydrogenase from Comamonas testosteroni (QH-EDH) contains two cofactors, 2,7,9-tricarboxy-1H-pyrrolo[2,3-f]quinoline-4,5-dione (PQQ) and heme c. Since previous studies on the kinetics of this enzyme suggested that both participate in electron transfer, spectroscopic investigations were performed of the oxidized and reduced holo- and apoenzyme (without PQQ but with heme c) to reveal the nature of the interaction between the two redox centers. From this it appears that the properties of the heme in the enzyme are affected by the presence of PQQ, as judged from the shift of the maxima in the ultraviolet/visible absorption spectra of the heme moiety in both reduced and oxidized QH-EDH and the 60-mV increase of the heme midpoint redox potential caused by PQQ addition. Also 1H-NMR spectroscopy was indicative for interaction since binding of PQQ induced shifts in the resonances of the methyl groups of the porphyrin ring in the oxidized form of the apoenzyme and a shift in the methionine heme ligand resonance of the reduced form of the apoenzyme. On the other hand, resonance Raman spectra of the heme in the different enzyme forms were nearly similar. These results suggest that a major effect of PQQ binding to apo-QH-EDH is a rotation of the methionine ligand of heme c. Since no intermediate 1H-NMR spectra were observed upon titration of apoenzyme with PQQ, apparently no exchange occurs of PQQ between (oxidized) holo- and apoenzyme at the NMR time scale and at that of the experiment.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of the iron-binding site in mammalian ferrochelatase by kinetic and Mossbauer methods, Franco, R., Moura J. J., Moura I., Lloyd S. G., Huynh B. H., Forbes W. S., and Ferreira G. C. , J Biol Chem, Nov 3, Volume 270, Number 44, p.26352-7, (1995) AbstractWebsite

All organisms utilize ferrochelatase (protoheme ferrolyase, EC to catalyze the terminal step of the heme biosynthetic pathway, which involves the insertion of ferrous ion into protoporphyrin IX. Kinetic methods and Mossbauer spectroscopy have been used in an effort to characterize the ferrous ion-binding active site of recombinant murine ferrochelatase. The kinetic studies indicate that dithiothreitol, a reducing agent commonly used in ferrochelatase activity assays, interferes with the enzymatic production of heme. Ferrochelatase specific activity values determined under strictly anaerobic conditions are much greater than those obtained for the same enzyme under aerobic conditions and in the presence of dithiothreitol. Mossbauer spectroscopy conclusively demonstrates that, under the commonly used assay conditions, dithiothreitol chelates ferrous ion and hence competes with the enzyme for binding the ferrous substrate. Mossbauer spectroscopy of ferrous ion incubated with ferrochelatase in the absence of dithiothreitol shows a somewhat broad quadrupole doublet. Spectral analysis indicates that when 0.1 mM Fe(II) is added to 1.75 mM ferrochelatase, the overwhelming majority of the added ferrous ion is bound to the protein. The spectroscopic parameters for this bound species are delta = 1.36 +/- 0.03 mm/s and delta EQ = 3.04 +/- 0.06 mm/s, distinct from the larger delta EQ of a control sample of Fe(II) in buffer only. The parameters for the bound species are consistent with an active site composed of nitrogenous/oxygenous ligands and inconsistent with the presence of sulfur ligands. This finding is in accord with the absence of conserved cysteines among the known ferrochelatase sequences. The implications these results have with regard to the mechanism of ferrochelatase activity are discussed.

Characterization of two dissimilatory sulfite reductases (desulforubidin and desulfoviridin) from the sulfate-reducing bacteria. Moessbauer and EPR studies, Moura, I., Legall J., Lino A. R., Peck H. D., Fauque G., Xavier A. V., Dervartanian D. V., Moura J. J. G., and Huynh B. H. , Journal of the American Chemical Society, 1988/02/17, Volume 110, Number 4, p.1075-1082, (1988) AbstractWebsite
Characterization of two dissimilatory sulfite reductases from sulfate-reducing bacteria, Huynh, B. H., Moura I., Lino A. R., Moura J. J. G., and Legall J. , Hyperfine Interactions, 1988, Volume 42, Number 1-4, p.905-908, (1988) AbstractWebsite
Characterization of two dissimilatory sulfite reductases from sulfate-reducing bacteria, Huynh, B., Moura I., Lino A., Moura J., and Legall J. , Hyperfine Interactions, Volume 42, Number 1, p.905-908, (1988) AbstractWebsite

Mössbauer, EPR, and biochemical techniques were used to characterize two dissimilatory sulfite reductases: desulforubidin from Desulfovibrio baculatus strain DSM 1743 and desulfoviridin from Desulfovibrio gigas . For each molecule of desulforubidin, there are two sirohemes and four [4Fe−4S] clusters. The [4Fe−4S] clusters are in the diamagnetic 2+ oxidation state. The sirohemes are high-spin ferric (S=5/2) and each siroheme is exchanged-coupled to a [4Fe−4S] 2+ cluster. Such an exchange-coupled siroheme-[4Fe−4S] unit has also been found in the assimilatory sulfite reductase from Escherichia coli /1/ and in a low-molecular weight sulfite reductase from Desulfovibrio vulgaris /2/. For each molecule of defulfoviridin, there are two tetrahydroporphyrin groups and four [4Fe−4S] 2+ clusters. To our surprise, we discovered that about 80% of the tetrahydroporphyrin groups, however, do not bind iron.

Chromatographic-based methods for pesticide determination in honey: An overview, Rial-Otero, R., Gaspar E. M., Moura I., and Capelo J. L. , Talanta, Feb 15, Volume 71, Number 2, p.503-514, (2007) AbstractWebsite

Nowadays the control of pesticides in honey is an issue of primary health importance as consequence of the increasing content of these chemicals in the aforementioned matrix. This poisoning has led to the worldwide increasing loss of bees since 1995. From Europe to Canada, scientist, beekeepers and chemical companies disagree about the reasons that have led to colony losses higher than 50% in some areas. This problem has become a public health issue due to the high honey worldwide consumption. The presence of pesticides in honey has been directly related to bees' mortality by some researchers through pesticide presence in (1) pollen, (2) honeycomb walls, (3) own bees and (4) honey. In this work we describe the actual state-of-the-art for pesticides determination in honey along with a review in this subject focused on sample treatments and instrumentation. Finally, future trends are also commented. (c) 2006 Elsevier B.V. All rights reserved.

Chromosome aberrations in cattle raised on bracken fern pasture, Moura, J. W., Stocco dos Santos R. C., Dagli M. L., D'Angelino J. L., Birgel E. H., and Becak W. , Experientia, Sep 15, Volume 44, Number 9, p.785-8, (1988) AbstractWebsite

Thirteen cows maintained on natural bracken fern (Pteridium aquilinum) were analyzed cytogenetically. The frequency of structural chromosome aberrations detected in peripheral blood cells was significantly higher when compared to that detected in animals raised on pasture containing no bracken fern. We discuss the clastogenic action of fern and its synergistic action with infection by type 2 and 4 papilloma virus in the same animals.

Cloning, sequencing and overexpression of the Desulfovibrio gigas ferredoxin gene in E. coli, Chen, B., Menon N. K., Dervertarnian L., Moura J. J., and Przybyla A. E. , FEBS Lett, Sep 12, Volume 351, Number 3, p.401-4, (1994) AbstractWebsite

We have cloned the gene encoding Desulfovibrio gigas ferredoxin using a photodigoxigenin-labelled probe synthesized with the polymerase chain reaction. The DNA sequence of the gene predicts a polypeptide of 58 residues after removal of the initial formyl methionine (polypeptide M(r) = 6,276). The ferredoxin gene was expressed in aerobically grown E. coli behind the lac promoter of pUC18 resulting in a high level of ferredoxin expression which comprises about 10% of the total cell protein. EPR analysis of recombinant ferredoxin revealed the presence of a [3Fe-4S] cluster which is characteristic of native D. gigas ferredoxin II.

Cobalt containing B12 cofactors from methanogenic bacteria - spectroscopic characterization, Lino, A. R., Xavier A. V., Moura I., Legall J., and Ljungdahl P. O. , Rev Portuguesa de Química, Volume 27, p.175-177, (1985) Abstract
A cobalt containing protein isolated from Desulfovibrio gigas, a sulfate reducer, Moura, J. J., Moura I., Bruschi M., Legall J., and Xavier A. V. , Biochem Biophys Res Commun, Feb 12, Volume 92, Number 3, p.962-70, (1980) AbstractWebsite
Cobalt-, zinc- and iron-bound forms of adenylate kinase (AK) from the sulfate-reducing bacterium Desulfovibrio gigas: purification, crystallization and preliminary X-ray diffraction analysis, Kladova, A. V., Gavel O. Y., Mukhopaadhyay A., Boer D. R., Teixeira S., Shnyrov V. L., Moura I., Moura J. J., Romao M. J., Trincao J., and Bursakov S. A. , Acta Crystallogr Sect F Struct Biol Cryst Commun, Sep 1, Volume 65, Number Pt 9, p.926-9, (2009) AbstractWebsite

Adenylate kinase (AK; ATP:AMP phosphotransferase; EC is involved in the reversible transfer of the terminal phosphate group from ATP to AMP. AKs contribute to the maintenance of a constant level of cellular adenine nucleotides, which is necessary for the energetic metabolism of the cell. Three metal ions, cobalt, zinc and iron(II), have been reported to be present in AKs from some Gram-negative bacteria. Native zinc-containing AK from Desulfovibrio gigas was purified to homogeneity and crystallized. The crystals diffracted to beyond 1.8 A resolution. Furthermore, cobalt- and iron-containing crystal forms of recombinant AK were also obtained and diffracted to 2.0 and 3.0 A resolution, respectively. Zn(2+)-AK and Fe(2+)-AK crystallized in space group I222 with similar unit-cell parameters, whereas Co(2+)-AK crystallized in space group C2; a monomer was present in the asymmetric unit for both the Zn(2+)-AK and Fe(2+)-AK forms and a dimer was present for the Co(2+)-AK form. The structures of the three metal-bound forms of AK will provide new insights into the role and selectivity of the metal in these enzymes.

Comparative electrochemical behavior of cytochrome c on aqueous solutions containing choline-based room temperature ionic liquids, Matias, S. C., Lourenço N. M. T., Fonseca J. P., and Cordas C. M. , ChemistrySelect, Volume 2, p.8701–8705, (2017) Website
Comparative electrochemical study of superoxide reductases, Cordas, C. M., Raleiras P., Auchere F., Moura I., and Moura J. J. , Eur Biophys J, Dec 6, Volume 41, Number 12, p.209-215, (2012)
A comparative spectroscopic study of two non-haem iron proteins lacking labile sulphide from Desulphovibrio gigas, Moura, I., Xavier A. V., Cammack R., Bruschi M., and Legall J. , Biochimica et Biophysica Acta (BBA) - Protein Structure, Volume 533, Number 1, p.156-162, (1978) AbstractWebsite
A Comparison between Vanadyl, Vanadate, and Decavanadate Effects in Actin Structure and Function: Combination of Several Spectroscopic Studies, Ramos, S., Moura J. J. G., and Aureliano M. , Spectroscopy: An International Journal, Volume 27, p.355-359, (2012)
The complete catalytic mechanism of Xanthine Oxidase: a computational study, Fernandes, H., Maia L., Ribeiro P. M., J.J.G. Moura, and Cerqueira N. M. , Inorg Chem Front, Volume 8, p.405, (2021)
Construção de um Bio-Eléctrodo Específico para Determinação de Nitritos, Almeida, M. G., Tavares P., and Moura J. J. G. , Bol. Soc. Port. Química, Volume 84, p.68-71, (2002) Abstract
Construction of effective disposable biosensors for point-of-care testing of nitrite, Monteiro, T., Rodrigues P. R., Gonçalves A. L., Moura J. J. G., Anorga L., Jubete E., Piknova B., Schechter A. N., Silveira C. M., and Almeida M. G. , Talanta, Volume 142, p.246-251, (2015)