Hydrogenases are powerful biocatalysts for the production of molecular hydrogen. However, many hydrogenases either are susceptible to oxygen inactivation or, in the case of Escherichia coli Hyd-1, are unable to produce hydrogen because their electron-transferring Fe-S clusters are too oxidizing. To make Hyd-1 a more robust hydrogen producer, Zhang et al. chose two sites near the distal [4Fe–4S] cluster where electrons initially enter Hyd-1 and covalently attached a silver nanocluster (AgNC) to the enzyme surface to make it photoactivatable. The AgNC attached via a cysteine residue installed at either site endowed Hyd-1 with the ability to produce hydrogen at pH 6 under anaerobic or aerobic conditions upon illumination. Covalent, site-specific attachment of the AgNC was necessary for activity, as wild-type Hyd-1 incubated with free AgNC was not active. Electrochemical experiments with AgNC-Hyd-1 complexes indicated that the AgNC is able to capture energized electrons at the protein surface, shuttling them to the internal electron transfer pathway via the distal [4Fe–4S] cluster. This approach provides a potentially versatile method for engineering enzymes with increased catalytic activity in reduction reactions.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Deane, C. Stick-on silver. Nat Chem Biol 16, 811 (2020). https://doi.org/10.1038/s41589-020-0605-y
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41589-020-0605-y