From protein engineering to artificial enzymes – biological and biomimetic approaches towards sustainable hydrogen production

Abstract

We review recent efforts aimed at generating efficient H2 producing systems, through engineering and mimicking of Nature's platinum, hydrogenases.

Spectroscopic investigations under whole-cell conditions provide new insight into the metal hydride chemistry of [FeFe]-hydrogenase

“…Under in vitro conditions it is well established that the incorporation of the [Fe 2 (adt)(CO) 4 (CN) 2 ] 2À complex ([2Fe] adt ) results in the spontaneous assembly of semi-synthetic hydrogenases indistinguishable from the native enzyme ([2Fe] adt -HydA1). 7,13,[41][42][43] We recently adopted this strategy for in vivo applications, enabling the preparation of fully functional, semisynthetic enzymes in both E. coli and cyanobacteria. 6,[44][45][46] Herein, we take advantage of this protocol to perform spectroscopic investigations of [FeFe]-hydrogenase in whole cells (Fig.…”

“…1,2 This reactivity makes [FeFe]-hydrogenases highly relevant for biotechnological H 2 production as an alternative to platinumbased electrolysis [3][4][5][6] and a biological blue-print for the design of synthetic catalysts. [7][8][9] Consequently, intense efforts have been invested in elucidating the structure and catalytic mechanism of these enzymes. 10,11 The reactivity of [FeFe]-hydrogenases is enabled by a hexanuclear iron complex, referred to as the hydrogen-forming cluster or simply the "H-cluster" (Fig.…”

New Approaches to an Old Problem: Original Techniques in [FeFe]-hydrogenase Research

“…30 Another important aspect is the preparation of [FeFe]-hydrogenases in which the diiron site is synthetically modified in order to generate non-natural H-clusters and enzymes with new properties. [73][74][75][76] In the case of Group A [FeFe]-hydrogenase, the active site cavity has been extensively explored through site-directed mutagenesis (Chapter 2.1.2). 19,[43][44][45][46] Of particular note in the context of organometallic variants is the critical importance of hydrogen-bonding interactions between C1 ( Figure 4) and the central nitrogen atom of the adt group.…”

Metagenomics Meets Electrochemistry: Utilizing the Huge Catalytic Potential From the Uncultured Microbial Majority for Energy-Storage

“…Given these drawbacks, hydrogen converting enzymes (hydrogenases) have gained more and more attraction: either as biological models for novel artificial catalysts or for direct application in biofuel cells or hydrogen production (Armstrong et al, 2009;Chenevier et al, 2013;Mazurenko et al, 2017;Esmieu et al, 2018;Le Goff and Holzinger, 2018;Qiu et al, 2019). Hydrogenases catalyze the interconversion of molecular hydrogen to protons and electrons (H 2 ↔ 2 H + + 2 e − ) ( Vignais and Billoud, 2007;Greening et al, 2016).…”