Energetics for Proton Reduction in FeFe Hydrogenase.

ABSTRACT: The energetics for proton reduction in FeFe-hydrogenase has been reinvestigated by theoretical modeling, in light of recent experiments. Two different mechanisms have been considered. In the first one, the bridging hydride position was blocked by the enzyme, which is the mechanism that has been supported by a recent spectroscopic study by Cramer et al. A major difficulty in the present study to agree with experimental energetics was to find the right position for the added proton in the first reduction step. It was eventually found that the best position was as a terminal hydride on the distal iron, which has not been suggested in any of the recent, experimentally based mechanisms. The lowest transition state was surprisingly found to be a bond formation between a proton on a cysteine and

SUBMITTER: Siegbahn PEM 

PROVIDER: S-EPMC7750917 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature