Electrochemical Characterization of Isolated Nitrogenase Cofactors from Azotobacter vinelandii

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 co...

Full description

Saved in:
Bibliographic Details
Published in:Chembiochem : a European journal of chemical biology 2020-06, Vol.21 (12), p.1773-1778
Main Authors: Lydon, Brian R., Lee, Chi Chung, Tanifuji, Kazuki, Sickerman, Nathaniel S., Newcomb, Megan P., Hu, Yilin, Ribbe, Markus W., Yang, Jenny Y.
Format: Article
Language:English
Subjects:
Azotobacter
Clusters
Cofactors
Electrochemical analysis
Electrochemistry
Homology
Iron
Molybdenum
Nitrogenase
nitrogenases
Proteins
redox properties
reduction potentials
Vanadium
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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. 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. Detailed fixation: In this study we investigated the redox properties 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) are described. The reduction potentials of the isolated cofactors are significantly more negative than previously measured values within the molybdenum–iron and vanadium–iron proteins.
ISSN:1439-4227
1439-7633
DOI:10.1002/cbic.201900425