Vibrational spectroscopy reveals the initial steps of biological hydrogen evolution.

Chem Sci

Institut für Chemie , Technische Universitaet Berlin, Strasse des 17. Juni 135 , D-10623 Berlin , Germany . Email: ; Email:

Published: November 2016

[FeFe] hydrogenases are biocatalytic model systems for the exploitation and investigation of catalytic hydrogen evolution. Here, we used vibrational spectroscopic techniques to characterize, in detail, redox transformations of the [FeFe] and [4Fe4S] sub-sites of the catalytic centre (H-cluster) in a monomeric [FeFe] hydrogenase. Through the application of low-temperature resonance Raman spectroscopy, we discovered a novel metastable intermediate that is characterized by an oxidized [FeFe] centre and a reduced [4Fe4S] cluster. Based on this unusual configuration, this species is assigned to the first, deprotonated H-cluster intermediate of the [FeFe] hydrogenase catalytic cycle. Providing insights into the sequence of initial reaction steps, the identification of this species represents a key finding towards the mechanistic understanding of biological hydrogen evolution.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5355867PMC
http://dx.doi.org/10.1039/c6sc01098aDOI Listing

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