Reaction Mechanism for CO Reduction by Mo-Nitrogenase Studied by QM/MM.

ABSTRACT: We have studied the conversion of two molecules of carbon monoxide to ethylene catalyzed by nitrogenase. We start from a recent crystal structure showing the binding of two carbon monoxide molecules to nitrogenase and employ the combined quantum mechanics and molecular mechanics approach. Our results indicate that the reaction is possible only if S2B dissociates as H₂S (i.e., the charge of the FeMo cluster remains the same as in the E₀ state, indicating that the Fe ions are formally reduced two steps when CO binds). Eight electrons and protons are needed for the reaction, and our mechanism suggests that the first four bind alternatively to the two carbon atoms. The C-C bond formation takes place already after the first protonation (in the E₃ state). The nex

SUBMITTER: Jiang H 

PROVIDER: S-EPMC11351180 | biostudies-literature | 2024 Aug

REPOSITORIES: biostudies-literature