Jump to main content
Jump to site search

Issue 1, 2014
Previous Article Next Article

Inaccessibility of the μ-hydride species in [FeFe] hydrogenases

Author affiliations

Abstract

[FeFe] hydrogenases catalyse the reversible formation and oxidation of H2. They presumably feature a hydride species as a key intermediate. The H ligand can either be bound between the iron atoms of the [2Fe]H subsite (μ-H) or terminally to the distal iron atom of the active site (terminal-H). Although the μ-H species is thermodynamically most stable, experimental evidence points to the terminal-H species as the relevant intermediate. In order to understand these contradictory results, we investigate the catalytic cycle of [FeFe] hydrogenases (including transition states) with a special focus on the role of the two possible hydride intermediates. For this, density functional theory calculations were carried out for a large quantum mechanical active-site model. It is shown that formation of the μ-H intermediate is prohibited by high activation barriers which are caused by interactions of the H cluster with surrounding amino acids. We provide direct evidence for the anchoring of the H cluster in the protein to be decisive for the kinetic hindrance of μ-H formation.

Graphical abstract: Inaccessibility of the μ-hydride species in [FeFe] hydrogenases

Back to tab navigation

Supplementary files

Publication details

The article was received on 19 Jun 2013, accepted on 16 Sep 2013 and first published on 20 Sep 2013


Article type: Edge Article
DOI: 10.1039/C3SC51700D
Chem. Sci., 2014,5, 215-221

  •   Request permissions

    Inaccessibility of the μ-hydride species in [FeFe] hydrogenases

    A. R. Finkelmann, M. T. Stiebritz and M. Reiher, Chem. Sci., 2014, 5, 215
    DOI: 10.1039/C3SC51700D

Search articles by author

Spotlight

Advertisements