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Photo‐Driven Hydrogen Evolution by an Artificial Hydrogenase Utilizing the Biotin‐Streptavidin Technology
Author(s) -
Keller Sascha G.,
Probst Benjamin,
Heinisch Tillmann,
Alberto Roger,
Ward Thomas R.
Publication year - 2018
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.201800036
Subject(s) - streptavidin , chemistry , hydrogenase , biotin , biotinylation , combinatorial chemistry , photochemistry , catalysis , hydrogen , biochemistry , organic chemistry
Photocatalytic hydrogen evolution by an artificial hydrogenase based on the biotin‐streptavidin technology is reported. A biotinylated cobalt pentapyridyl‐based hydrogen evolution catalyst ( HEC ) was incorporated into different mutants of streptavidin. Catalysis with [Ru(bpy) 3 ]Cl 2 as a photosensitizer ( PS ) and ascorbate as sacrificial electron donor ( SED ) at different pH values highlighted the impact of close lying amino acids that may act as a proton relay under the reaction conditions (Asp, Arg, Lys). In the presence of a close‐lying lysine residue, both, the rates were improved, and the reaction was initiated much faster. The X‐ray crystal structure of the artificial hydrogenase reveals a distance of 8.8 Å between the closest lying Co‐moieties. We thus suggest that the hydrogen evolution mechanism proceeds via a single Co centre. Our findings highlight that streptavidin is a versatile host protein for the assembly of artificial hydrogenases and their activity can be fine‐tuned via mutagenesis.