Isolation of a molybdenum--iron cluster from nitrogenase.
Open Access
- 1 June 1981
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 78 (6) , 3438-3440
- https://doi.org/10.1073/pnas.78.6.3438
Abstract
A Mo-Fe cluster containing 6 Fe atoms/Mo was isolated by methyl ethyl ketone extraction of component I of nitrogenase from Azotobacter vinelandii. The cluster has no EPR signal in the g = 4 region but has an intense signal at g = 2.05 and 2.01. After the cluster was transferred from methyl ethyl ketone to N-methylformamide, the signal in the g = 2 region disappeared and a signal similar to that found with Fe-Mo cofactor appeared. The Mo-Fe cluster is the EPR-active center that undergoes reversible oxidation-reduction during catalytic turnover at the active site of the enzyme. In contrast to the Fe-Mo cofactor, which contains 8 Fe atoms/Mo, the Mo-Fe cluster failed to activate either inactive component I in extracts of A. vinelandii mutant strain UW45 or tungsten-containing component I from wild-type A. vinelandii. The Mo-Fe cluster showed as much acetylene-reduction activity with sodium borohydride as the reductant as did the Fe-Mo cofactor. Like nitrogenase-dependent and Fe-Mo cofactor-dependent acetylene reduction, the Mo-Fe cluster-dependent acetylene reduction is strongly inhibited by CO.This publication has 17 references indexed in Scilit:
- Nitrogenase XI: Mössbauer studies on the cofactor centers of the MoFe protein from Azotobacter vinelandii OPBiochimica et Biophysica Acta (BBA) - Protein Structure, 1979
- Acetylene reduction by the iron-molybdenum cofactor from nitrogenaseBiochemical and Biophysical Research Communications, 1978
- Novel metal cluster in the iron-molybdenum cofactor of nitrogenase. Spectroscopic evidenceJournal of Biological Chemistry, 1978
- Isolation of an iron-molybdenum cofactor from nitrogenaseProceedings of the National Academy of Sciences, 1977
- Nitrogenase. VIII. Mössbauer and EPR spectroscopy. The MoFe protein component from Azotobacter vinelandii OPBiochimica et Biophysica Acta (BBA) - Protein Structure, 1975
- Nitrogenase IV. Simple method of purification to homogeneity of nitrogenase components from Azotobacter vinelandiiBiochimica et Biophysica Acta (BBA) - Bioenergetics, 1973
- Electron paramagnetic resonance studies on nitrogenase. III. Function of magnesium adenosine 5′-triphosphate and adenosine 5′-diphosphate in catalysis by nitrogenaseBiochimica et Biophysica Acta (BBA) - Bioenergetics, 1973
- Nitrogenase. III. Nitrogenaseless mutants of Azotobacter vinelandii: Activities, cross-reactions and epr spectraBiochimica et Biophysica Acta (BBA) - Bioenergetics, 1973
- Nitrogenase of Klebsiella pneumoniae: electron-paramagnetic-resonance studies on the catalytic mechanismBiochemical Journal, 1972
- Inhibitors of nitrogen fixation in extracts from Clostridium pasteurianumBiochimica et Biophysica Acta (BBA) - General Subjects, 1965