Metadata only
Date
2011-12-21Type
- Journal Article
ETH Bibliography
yes
Altmetrics
Abstract
The H2-evolving potential of [FeFe] hydrogenases is severely limited by the oxygen sensitivity of this class of enzymes. Recent experimental studies on hydrogenase from C. reinhardtii point to O2-induced structural changes in the [Fe4S4] subsite of the H cluster. Here, we investigate the mechanistic basis of this observation by means of density functional theory. Unexpectedly, we find that the isolated H cluster shows a pathological catalytic activity for the formation of reactive oxygen species such as O2– and HO2–. After protonation of O2–, an OOH radical may coordinate to the Fe atoms of the cubane, whereas H2O2 specifically reacts with the S atoms of the cubane-coordinating cysteine residues. Both pathways are accompanied by significant structural distortions that compromise cluster integrity and thus catalytic activity. These results explain the experimental observation that O2-induced inhibition is accompanied by distortions of the [Fe4S4] moiety and account for the irreversibility of this process. Show more
Publication status
publishedExternal links
Journal / series
Journal of the American Chemical SocietyVolume
Pages / Article No.
Publisher
American Chemical SocietyOrganisational unit
03736 - Reiher, Markus / Reiher, Markus
More
Show all metadata
ETH Bibliography
yes
Altmetrics