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Evaluation of the Catalytic Relevance of the CO‐Bound States of V‐Nitrogenase
Author(s) -
Lee Chi Chung,
Wilcoxen Jarett,
Hiller Caleb J.,
Britt R. David,
Hu Yilin
Publication year - 2018
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201800189
Subject(s) - nitrogenase , catalysis , chemistry , moiety , substrate (aquarium) , population , enzyme , stereochemistry , oxidation state , photochemistry , crystallography , computational chemistry , nitrogen fixation , biochemistry , organic chemistry , biology , ecology , demography , sociology , nitrogen
Binding and activation of CO by nitrogenase is a topic of interest because CO is isoelectronic to N 2 , the physiological substrate of this enzyme. The catalytic relevance of one‐ and multi‐CO‐bound states (the lo‐CO and hi‐CO states) of V‐nitrogenase to C−C coupling and N 2 reduction was examined. Enzymatic and spectroscopic studies demonstrate that the multiple CO moieties in the hi‐CO state cannot be coupled as they are, suggesting that C−C coupling requires further activation and/or reduction of the bound CO entity. Moreover, these studies reveal an interesting correlation between decreased activity of N 2 reduction and increased population of the lo‐CO state, pointing to the catalytic relevance of the belt Fe atoms that are bridged by the single CO moiety in the lo‐CO state. Together, these results provide a useful framework for gaining insights into the nitrogenase‐catalyzed reaction via further exploration of the utility of the lo‐CO conformation of V‐nitrogenase.