Chemogenetic protein engineering: an efficient tool for the optimization of artificial metalloenzymes

Artificial metalloenzymes, based on the incorporation of a catalytically active organometallic moiety within a host protein, lie at the interface between organometallic and enzymatic catalysis. In terms of activity, reaction repertoire substrate range and operating conditions, they take advantage of the versatility of the organometallic chemistry. In contrast the enantioselectivity is determined by the biomolecular scaffold, which provides as well defined second coordination sphere to the organometallic moiety, reminiscent of enzymes. The attractive feature of such systems is their optimization potential, which combines chemical and genetic method (i.e. chemogenetic) to screen diversity space. This feature article describes the implementation of such an optimization protocol for artificial transfer hydrogenases, for which we have the most detailed understanding.