13C NMR characterization of an exchange reaction between CO and CO2 catalyzed by carbon monoxide dehydrogenase.

ABSTRACT: Carbon monoxide dehydrogenase (CODH) catalyzes the reversible oxidation of CO to CO2 at a nickel-iron-sulfur cluster (the C-cluster). CO oxidation follows a ping-pong mechanism involving two-electron reduction of the C-cluster followed by electron transfer through an internal electron transfer chain to external electron acceptors. We describe 13C NMR studies demonstrating a CODH-catalyzed steady-state exchange reaction between CO and CO2 in the absence of external electron acceptors. This reaction is characterized by a CODH-dependent broadening of the 13CO NMR resonance; however, the chemical shift of the 13CO resonance is unchanged, indicating that the broadening is in the slow exchange limit of the NMR experiment. The 13CO line broadening occurs with a rate constant (1080 s-1 at 20 degre

SUBMITTER: Seravalli J 

PROVIDER: S-EPMC2664834 | biostudies-literature | 2008 Jul

REPOSITORIES: biostudies-literature