Direct Assessment of the Reduction Potential of the [4Fe−4S]1+/0 Couple of the Fe Protein from Azotobacter vinelandii
- 24 September 2002
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 124 (41), 12100-12101
- https://doi.org/10.1021/ja026478f
Abstract
Recently, it has been demonstrated that the [4Fe−4S] cluster of the Fe protein of nitrogenase from Azotobacter vinelandii can be reduced to an unprecedented all-ferrous state. In this work, the reduction potential for the formation of the all-ferrous state is measured by the reactions of the reduced and oxidized Fe protein with a variety of chemical redox active agents, and by mediated spectroelectrochemical titration. Redox titrations obtain a potential ca. −790 mV/NHE for the formation of the all-ferrous state, a value consistent with the chemical reactivity experiments and with recent theoretical calculations. At present, no known redox protein in A. vinelandii is capable of generating the all-ferrous Fe protein.Keywords
This publication has 15 references indexed in Scilit:
- From ATP to Electron Transfer: Electrostatics and Free-Energy Transduction in NitrogenaseThe Journal of Physical Chemistry B, 2001
- Crystal Structure of the All-Ferrous [4Fe-4S]0 Form of the Nitrogenase Iron Protein from Azotobacter vinelandii,Biochemistry, 2000
- An All-ferrous State of the Fe Protein of NitrogenaseJournal of Biological Chemistry, 1998
- All-Ferrous Titanium(III) Citrate Reduced Fe Protein of Nitrogenase: An XAS Study of Electronic and Metrical StructureJournal of the American Chemical Society, 1998
- Changes in the Midpoint Potentials of the Nitrogenase Metal Centers as a Result of Iron Protein−Molybdenum-Iron Protein Complex FormationBiochemistry, 1997
- Mössbauer and EPR Evidence for an All-Ferrous Fe4S4 Cluster with S = 4 in the Fe Protein of NitrogenaseJournal of the American Chemical Society, 1997
- Characterization of a 7Fe Ferredoxin Isolated from the Marine DenitrifierPseudomonas nauticaStrain 617: Spectroscopic and Electrochemical StudiesBiochemical and Biophysical Research Communications, 1996
- Ligand Structural Effects on the Electrochemistry of Chromium(III) Amino Carboxylate ComplexesInorganic Chemistry, 1996
- Kinetics of the Cr(II)edta reduction of the water-soluble Fe4S4(SCH2CH2CO2)46- cluster to the superreduced form and related studiesInorganic Chemistry, 1980
- The Redox Potential of Dithionite and SO−2 from Equilibrium Reactions with Flavodoxins, Methyl Viologen and Hydrogen plus HydrogenaseEuropean Journal of Biochemistry, 1978