title: Iron-molybdenum cofactor of nitrogenase: electrochemical determination of the electron stoichiometry of the oxidized/semi-reduced couple.
abstract: The number of electrons involved in the more positive of the two redox couples of the iron-molybdenum cofactor of Azotobacter vinelandii nitrogenase has been investigated by controlled potential coulometry in both the oxidizing and reducing directions. A n value of 1 was determined for interconversion of the oxidized and semi-reduced states of the cofactor. This electron count was confirmed by double integration of the S = 3/2 electron paramagnetic resonance signal exhibited by the semi-reduced state.
authors.affiliation: Department of Chemistry, Indiana University-Purdue University, Indianapolis 46223.
authors.forename: F A
authors.initials: FA
authors.lastname: Schultz
authors.forename: S F
authors.initials: SF
authors.lastname: Gheller
authors.forename: W E
authors.initials: WE
authors.lastname: Newton
mesh_terms: D001395:Azotobacter / Q000201:enzymology; D004563:Electrochemistry; D004578:Electron Spin Resonance Spectroscopy; D005288:Ferredoxins / Q000378:metabolism; D008983:Molybdoferredoxin / Q000378:metabolism; D009591:Nitrogenase; D010084:Oxidation-Reduction
chemical_list: D005288:Ferredoxins; D008983:Molybdoferredoxin; D009591:Nitrogenase