Controlling the optical and catalytic properties of artificial metalloenzyme photocatalysts using chemogenetic engineering

Abstract

Visible light photocatalysis enables a broad range of organic transformations that proceed via single electron or energy transfer. Metal polypyridyl complexes are among the most commonly employed visible light photocatalysts....

Iridium(III) Polypyridine Artificial Metalloenzymes with Tunable Photophysical Properties: a New Platform for Visible Light Photocatalysis in Aqueous Solution

“…A similar phenomenon was also observed for Ru(II) ArMs in our previous study. 13,22,23 The CD spectra for POP-Z53-1-5 acquired at 20-100 °C were essentially identical, suggesting that cofactor incorporation does not significantly reduce the high stability of the POP scaffold (Figure S8).…”

“…[9][10][11][12] We recently established that artificial metalloenzyme (ArM) photocatalysts could be constructed by covalently linking tris-bipyridine Ru(II) complexes within the large active site of a prolyl oligopeptidase (POP) from Pyrococcus furiosus. 13 These ArMs afforded higher yields and rates for the [2+2] photocycloaddition of dienones than Ru(bpy)3 2+ , indicating that the POP scaffolds could be an effective platform to enhance the reactivity of photocatalysts. Incorporating Ir(III) complexes within POP would significantly expand the range of processes that could be achieved using this platform.…”

Design of Artificial Enzymes: Insights into Protein Scaffolds

“…For both reactions, the ArMs gave improved yields and rate acceleration compared with the metal cofactor used alone, due to an entropic effect. As almost no preference towards one of the enantiomers was observed, it appears that the binding pocket of POP is not suitable to ensure stereoselectivity [77] …”

Photobiocatalysis for Abiological Transformations

“…In 2015, Lewis and co-workers constructed an artificial photoenzyme by using click chemistry to conjugate a modified acridinium 9-mesityl-10-methyl (Acr + -Mes) cofactor to an unnatural amino acid within a prolyl oligopeptidase for the sulfoxidation of thioanisoles. , For the conjugation, they developed a large pocket for entrance of the artificial cofactor by introducing four alanine mutations and used a previously developed platform in which addition of bicyclo­[6,1,0]­nonyne moiety allowed for covalent linkage to a p -azido- l -phenylalanine substituted protein. While control experiments confirm that successful bioconjugation of the photocatalysts occurs, the constructed artificial photoenzyme suffered lower yields in all cases when compared to the lone Acr + -Mes photocatalyst.…”