Accessing iridium Cp* as a cofactor for artificial metalloenzymes.

Abstract

By introducing new-to-nature transformations, artificial metalloenzymes hold great potential for expanding the biosynthetic toolbox. The chemistry of an active cofactor in these enzymes is highly dependent on how the holoprotein is assembled, potentially limiting the choice of organometallic complexes amenable to incorporation and ability of the protein structure to influence the metal centre. We have previously reported a method utilising ligand exchange as a means to introduce ruthenium-arene fragments into a four-helix bundle protein. In this work we expand the scope of this method to incorporate an iridium pentamethylcyclopentadienyl fragment into a four-helix bundle, yielding an artificial metalloenzyme with improved transfer hydrogenation properties, highlighting that understanding ligand exchange reactions is important for speciation control.