The Nonphysiological Reductant Sodium Dithionite and [FeFe] Hydrogenase: Influence on the Enzyme Mechanism.

ABSTRACT: [FeFe] hydrogenases are highly active enzymes for interconverting protons and electrons with hydrogen (H₂). Their active site H-cluster is formed of a canonical [4Fe-4S] cluster ([4Fe-4S]_H) covalently attached to a unique [2Fe] subcluster ([2Fe]_H), where both sites are redox active. Heterolytic splitting and formation of H₂ takes place at [2Fe]_H, while [4Fe-4S]_H stores electrons. The detailed catalytic mechanism of these enzymes is under intense investigation, with two dominant models existing in the literature. In one model, an alternative form of the active oxidized state H_ox, named H_oxH, which forms at low pH in the presence of the nonphysiological reductant sodium dithionite (NaDT), is believed to p

SUBMITTER: Martini MA 

PROVIDER: S-EPMC8569811 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature