Evaluation of the Catalytic Relevance of the CO‐Bound States of V‐Nitrogenase |
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| Authors: | Dr Chi Chung Lee Dr Jarett Wilcoxen Caleb J Hiller Prof?Dr R David Britt Prof?Dr Yilin Hu |
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| Institution: | 1. Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, USA;2. Department of Chemistry, University of California, Davis, Davis, CA, USA;3. Department of Chemistry, University of California, Irvine, Irvine, CA, USA |
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| Abstract: | Binding and activation of CO by nitrogenase is a topic of interest because CO is isoelectronic to N2, 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 N2 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 N2 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. |
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| Keywords: | CO binding CO reduction cofactor nitrogenase vanadium |
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