Residues surrounding the active centre of carbon monoxide dehydrogenase are key in converting [Formula: see text] to CO.

ABSTRACT

The enzyme carbon monoxide dehydrogenase is capable of efficiently converting [Formula see text] to CO and, therefore, can enable an affordable [Formula see text] recycling strategy. The reduction of [Formula see text] occurs at a peculiar nickel-iron-sulfur cluster, following a mechanism that remains little understood. In this study, we have used ab initio molecular dynamics simulations to explore the free energy landscape of the reaction. We predict the existence of a COOH ligand that strongly interacts with the surrounding protein residues and favours a mechanism where a [Formula see text] molecule is eliminated before CO. We have taken advantages of the insights offered by our simulations to revisit the catalytic mechanism and the role of the residues surrounding the active centre in particular, thus assisting in the design of inorganic catalysts that mimic the enzyme.