On the prosthetic groups of the NiFe sulfhydrogenase from Pyrococcus furiosus: topology, structure, and temperature-dependent redox chemistry

• Tipo: Artigo em Revista Científica Internacional
• Data: 1999

Autores

Silva, PJ (Autor) Outra; de Castro, B (Autor) FCUP; Hagen, WR (Autor) Outra

Revista

Título: Journal of Biological Inorganic Chemistry

Vol. 4

Páginas: 284-291

ISSN: 0949-8257

Editora: Springer Nature

Indexação

ISI Web of Knowledge - 28 Citações

Scopus - 24 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-001-472

DOI: 10.1007/s007750050314

Abstract (EN): The sulfhydrogenase complex of Pyrococcus furiosus is an alpha beta gamma delta heterotetramer with both hydrogenase activity (borne by the alpha delta subunits) and sulfur reductase activity (carried by the beta gamma subunits). The beta-subunit contains at least two [4Fe-4S] cubanes and the gamma-subunit contains one [2Fe-2S] cluster and one FAD molecule. The delta-subunit contains three [4Fe-4S] cubanes and the alpha-subunit carries the NiFe dinuclear center. Only three Fe/S signals are observed in EPR-monitored reduction by dithionite, NADPH, or internal substrate upon heating. All other clusters presumably have reduction potentials well below that of the H+/H-2 couple. Heat-induced reduction by internal substrate allows, for the first time, EPR monitoring of the NiFe center in a hyperthermophilic hydrogenase, which passes through a number of states, some of which are similar to states previously defined for mesophilic hydrogenases. The complexity of the observed transitions reflects a combination of temperature-dependent activation and temperature-dependent reduction potentials.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 8