The iron-sulfur centers of the soluble [NiFeSe] hydrogenase, from Desulfovibrio baculatus (DSM 1743). EPR and Mössbauer characterization.
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.
Teixeira
M
M
Centro de Química Estrutural, Lisboa, Portugal.
Moura
I
I
Fauque
G
G
Dervartanian
D V
DV
Legall
J
J
Peck
H D
HD
Moura
J J
JJ
Huynh
B H
BH
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
D007506:Iron-Sulfur Proteins; D046911:Macromolecular Substances; D008667:Metalloproteins; D009532:Nickel; C058560:nickel-iron-selenium hydrogenase; D006864:Hydrogenase; D012643:Selenium