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Electrochemical Characterization of Isolated Nitrogenase Cofactors from Azotobacter vinelandii

Journal Article · · ChemBioChem: a European journal of chemical biology
 [1];  [2];  [2];  [2];  [2];  [2];  [2];  [2]
  1. Univ. of California, Irvine, CA (United States); OSTI
  2. Univ. of California, Irvine, CA (United States)
+ Show Author Affiliations

The nitrogenase cofactors are structurally and functionally unique in biological chemistry. Despite a substantial amount of spectroscopic characterization of protein-bound and isolated nitrogenase cofactors, electrochemical characterization of these cofactors and their related species is far from complete. Herein we present voltammetric studies of three isolated nitrogenase cofactor species: the iron–molybdenum cofactor (M-cluster), iron–vanadium cofactor (V-cluster), and a homologue to the iron–iron cofactor (L-cluster). We observe two reductive events in the redox profiles of all three cofactors. Of the three, the V-cluster is the most reducing. The reduction potentials of the isolated cofactors are significantly more negative than previously measured values within the molybdenum–iron and vanadium–iron proteins. Finally, the outcome of this study provides insight into the importance of the heterometal identity, the overall ligation of the cluster, and the impact of the protein scaffolds on the overall electronic structures of the cofactors.

Research Organization:
Univ. of California, Irvine, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC); National Science Foundation (NSF)
Grant/Contract Number:
SC0012150
OSTI ID:
1802308
Journal Information:
ChemBioChem: a European journal of chemical biology, Journal Name: ChemBioChem: a European journal of chemical biology Journal Issue: 12 Vol. 21; ISSN 1439-4227
Publisher:
ChemPubSoc EuropeCopyright Statement
Country of Publication:
United States
Language:
English

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Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
59 BASIC BIOLOGICAL SCIENCES
biochemistry & molecular biology
cofactors
electrochemistry
nitrogenases
pharmacology & pharmacy
redox properties
reduction potentials