title: The iron-sulfur centers of the soluble [NiFeSe] hydrogenase, from Desulfovibrio baculatus (DSM 1743). EPR and Mössbauer characterization.
abstract: The soluble (cytoplasmic plus periplasmic) Ni/Fe-S/Se-containing hydrogenase from Desulfovibrio baculatus (DSM 1743) was purified from cells grown in an 57Fe-enriched medium, and its iron-sulfur centers were extensively characterized by Mössbauer and EPR spectroscopies. The data analysis excludes the presence of a [3Fe-4S] center, either in the native (as isolated) or in the hydrogen-reduced states. In the native state, the non-heme iron atoms are arranged as two diamagnetic [4Fe-4S]2+ centers. Upon reduction, these two centers exhibit distinct and unusual Mössbauer spectroscopic parameters. The centers were found to have similar mid-point potentials (approximately -315 mV) as determined by oxidation-reduction titratins followed by EPR.
authors.affiliation: Centro de Química Estrutural, Lisboa, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: Teixeira
authors.forename: I
authors.initials: I
authors.lastname: Moura
authors.forename: G
authors.initials: G
authors.lastname: Fauque
authors.forename: D V
authors.initials: DV
authors.lastname: Dervartanian
authors.forename: J
authors.initials: J
authors.lastname: Legall
authors.forename: H D
authors.initials: HD
authors.lastname: Peck
authors.forename: J J
authors.initials: JJ
authors.lastname: Moura
authors.forename: B H
authors.initials: BH
authors.lastname: Huynh
mesh_terms: D003901:Desulfovibrio / Q000201:enzymology*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D006864:Hydrogenase / Q000302:isolation & purification / Q000378:metabolism*; D007506:Iron-Sulfur Proteins / Q000302:isolation & purification / Q000378:metabolism*; D046911:Macromolecular Substances; D008667:Metalloproteins / Q000378:metabolism*; D009532:Nickel / Q000032:analysis; D011487:Protein Conformation; D012643:Selenium / Q000032:analysis; D013057:Spectrum Analysis / Q000379:methods
chemical_list: D007506:Iron-Sulfur Proteins; D046911:Macromolecular Substances; D008667:Metalloproteins; D009532:Nickel; C058560:nickel-iron-selenium hydrogenase; D006864:Hydrogenase; D012643:Selenium