Reactivity Tuning of Metal‐Free Artificial Photoenzymes through Binding Site Specific Bioconjugation

Abstract

Abstract The design and development of artificial metal‐free photoenzymes aims to combine the selectivity of enzymatic reactions with the benefits of modern synthetic photocatalysts. Removing the need for rare earth metals and allowing for milder reaction conditions, leading to a more sustainable catalytic system. Here, we present the design of a novel artificial photoenzyme by integrating an organophotocatalytic moiety based on a donor‐acceptor design into a steroid carrier protein (SCP‐2L). SCP‐2L possesses a hydrophobic tunnel facilitating substrate binding in aqueous media. The photocatalyst was site‐selectively bound to three SCP‐2L variants, possessing a non‐native cysteine residue strategically placed around the hydrophobic tunnel of the protein. The three modified photoenzymes were shown to be selective for the oxidation of organic sulfides giving up to 192 turnovers.