Multifrequency EPR Study of Fe(3+) and Co(2+) in the Active Site of Desulforedoxin,
Mathies, G., Almeida R. M., Gast P., Moura J. J., and Groenen E. J.
, J Phys Chem B, Volume 116, Issue 24, p.7122-7128, (2012)
Conversion of adrenaline to indolic derivatives by the human erythrocyte plasma membrane,
Marques, F., Duarte R. O., Moura J. J., and Bicho M. P.
, Biol Signals, Sep-Oct, Volume 5, Number 5, p.275-82, (1996)
AbstractThe conversion of adrenaline to aminochromes by the human erythrocyte plasma membranes at pH 9.5 was shown to be a complex reaction that proceeded at least by two distinct phases. The first one, corresponding to the formation of adrenochrome, is catalyzed in the presence of the membranes, suggesting the involvement of an enzyme-mediated process. Active oxygen species were identified as intermediates during this phase. Oxygen radical scavengers (catalase and superoxide dismutase) suggested H2O2 and O2- involvement. Adrenochrome formation was stimulated by NADH indicating the participation of another enzyme (NADH dehydrogenase) which is known to be present in the human erythrocyte plasma membrane. The second phase, corresponding to the disappearance of adrenochrome, is also stimulated by NADH and inhibited in the presence of the membranes. In this reaction, adrenochrome is converted to aminochromes via adrenochrome semiquinone. The formation of radical species is demonstrated by EPR spectroscopy. The results led to the proposal of a mechanism for the formation of adrenochrome and other oxidation products from adrenaline.
Kinetic and structural studies of aldehyde oxidoreductase from Desulfovibrio gigas reveal a dithiolene-based chemistry for enzyme activation and inhibition by H2O2,
Marangon, J., Correia H. D., Brondino C. D., Moura J. J. G., Romao M. J., Gonzalez P. J., and Santos-Silva T.
, PLoS One, Volume 8, p.e83234, (2013)
Substrate-dependent modulation of the enzymatic catalytic activity: Reduction of nitrate, chlorate and perchlorate by respiratory nitrate reductase from Marinobacter hydrocarbonoclasticus 617,
Marangon, J., de Sousa Paes P. M., Moura I., Brondino C. D., Moura J. J., and González P. J.
, Biochim Biophys Acta, Volume 1817, Issue 7, p.1072-1082, (2012)
Synthesis and characterization of [S2MoS2Cu(n-SPhF)]2−(n=o, m, p) clusters: Potential 19F-NMR structural probes for Orange Protein,
Maiti, B. K., Avilés T., Moura I., Pauleta S. R., and Moura J. J. G.
, Inorg Chem Commun, Volume 45, p.97-100, (2014)
One Electron Reduced Square Planar Bis(benzene-1,2-dithiolato) Copper Dianionic Complex and Redox Switch by O2/HO-,
Maiti, B. K., Maia L. B., Pal K., Pakira B., Aviles T., Moura I., Pauleta S. R., Nuñez J. L., Rizzi A. C., Brondino C. D., Sarkar S., and Moura J. J. G.
, Inorg Chem, Volume 53, p.12799-12808, (2014)
Rearrangement of Mo-Cu-S Cluster Reflects the Structural Instability of Orange Protein Cofactor,
Maiti, B. K., Avilés T., Carepo M. S., Moura I., S.R. Pauleta, and Moura J. J. G.
, Z Anorg Allg Chem, Volume 639, p.1361-1364, (2013)
Designed Metal-ATCUN Derivatives: Redox and Non-redox-Based Applications Relevant for Chemistry, Biology, and Medicine,
Maiti, B. K., Govil N., Kundu T., and J.J.G. Moura
, iScience, Volume 23, p.101792, (2020)
Protein-Assisted Formation of Molybdenum Heterometallic Clusters: Evidence for the Formation of S2MoS2−M−S2MoS2 Clusters with M = Fe, Co, Ni, Cu, or Cd within the Orange Protein,
Maiti, B. K., Maia L. B., Pauleta S. R., Moura I., and Moura J. J. G.
, Inorg Chem, Volume 56, p.2210−2220, (2017)
Incorporation of molybdenum in rubredoxin: Models for mononuclear molybdenum enzymes,
Maiti, B. K., Maia L. B., Silveira C., Todorovic S., Carreira C., Carepo M., Grazina R., Moura I., and Moura J. J. G.
, J Biol Inorg Chem, Volume 20, p.821-829, (2015)
Insights into the molybdenum/copper heterometallic cluster assembly in the orange protein: probing intermolecular interactions with an artificial metal-binding ATCUN tag,
Maiti, B. K., Almeida R. M., Maia L. B., Moura I., and Moura J. J. G.
, Inorg Chem, Volume 56, p.8900-8911, (2017)
Unusual reduction mechanism of copper in cysteine-rich environment,
Maiti, B. K., Maia L., Moro A. J., Lima J. C., Cordas C., Moura I., and Moura J. J. G.
, Inorg Chem, Volume 57, p.8078-8088, (2018)
Synthesis of [MoS4]2 – M (M = Cu and Cd) clusters: Potential NMR structural probes for orange protein,
Maiti, B. K., Avilés T., Matzapetakis M., Moura I., Pauleta S. R., and Moura J. J. G.
, Eur J Inorg Chem , Volume 2012, p.4159-4166, (2012)
NADH oxidase activity of rat and human liver xanthine oxidoreductase: potential role in superoxide production,
Maia, L., Duarte R. O., Ponces-Freire A., Moura J. J., and Mira L.
, J Biol Inorg Chem, Aug, Volume 12, Number 6, p.777-87, (2007)
AbstractTo characterise the NADH oxidase activity of both xanthine dehydrogenase (XD) and xanthine oxidase (XO) forms of rat liver xanthine oxidoreductase (XOR) and to evaluate the potential role of this mammalian enzyme as an O2*- source, kinetics and electron paramagnetic resonance (EPR) spectroscopic studies were performed. A steady-state kinetics study of XD showed that it catalyses NADH oxidation, leading to the formation of one O2*- molecule and half a H(2)O(2) molecule per NADH molecule, at rates 3 times those observed for XO (29.2 +/- 1.6 and 9.38 +/- 0.31 min(-1), respectively). EPR spectra of NADH-reduced XD and XO were qualitatively similar, but they were quantitatively quite different. While NADH efficiently reduced XD, only a great excess of NADH reduced XO. In agreement with reductive titration data, the XD specificity constant for NADH (8.73 +/- 1.36 microM(-1) min(-1)) was found to be higher than that of the XO specificity constant (1.07 +/- 0.09 microM(-1) min(-1)). It was confirmed that, for the reducing substrate xanthine, rat liver XD is also a better O2*- source than XO. These data show that the dehydrogenase form of liver XOR is, thus, intrinsically more efficient at generating O2*- than the oxidase form, independently of the reducing substrate. Most importantly, for comparative purposes, human liver XO activity towards NADH oxidation was also studied, and the kinetics parameters obtained were found to be very similar to those of the XO form of rat liver XOR, foreseeing potential applications of rat liver XOR as a model of the human liver enzyme.
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