Issue 45, 2018

Hydrogen evolution from water catalyzed by cobalt-mimochrome VI*a, a synthetic mini-protein

Abstract

A synthetic enzyme is reported that electrocatalytically reduces protons to hydrogen (H2) in water near neutral pH under aerobic conditions. Cobalt mimochrome VI*a (CoMC6*a) is a mini-protein with a cobalt deuteroporphyrin active site within a scaffold of two synthetic peptides covalently bound to the porphyrin. Comparison of the activity of CoMC6*a to that of cobalt microperoxidase-11 (CoMP11-Ac), a cobalt porphyrin catalyst with a single “proximal” peptide and no organized secondary structure, reveals that CoMC6*a has significantly enhanced longevity, yielding a turnover number exceeding 230 000, in comparison to 25 000 for CoMP11-Ac. Furthermore, comparison of cyclic voltammograms of CoMC6*a and CoMP11-Ac indicates that the trifluoroethanol-induced folding of CoMC6*a lowers the overpotential for catalytic H2 evolution by up to 100 mV. These results demonstrate that even a minimal polypeptide matrix can enhance longevity and efficiency of a H2-evolution catalyst.

Graphical abstract: Hydrogen evolution from water catalyzed by cobalt-mimochrome VI*a, a synthetic mini-protein

Supplementary files

Article information

Article type
Edge Article
Submitted
29 Apr 2018
Accepted
14 Sep 2018
First published
14 Sep 2018
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2018,9, 8582-8589

Hydrogen evolution from water catalyzed by cobalt-mimochrome VI*a, a synthetic mini-protein

V. Firpo, J. M. Le, V. Pavone, A. Lombardi and K. L. Bren, Chem. Sci., 2018, 9, 8582 DOI: 10.1039/C8SC01948G

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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