Symmetry-Adapted Synthesis of Dicopper Oxidases with Divergent Dioxygen Reactivity

Abstract

Artificial metalloenzymes have fed our understanding of how inorganic reactivities emerge, evolve, and diversify in protein environments. Herein, we created dinuclear copper oxidases by genetically encoding a metal-ligating unnatural amino acid (bpy-Ala) per protomer in the vicinity of the innate C2 rotational axis of a homo-oligomeric protein. The inherent protein symmetry allows the precise multiplication and placement of two Cu(bpy) species. Depending on the location of bpy-Ala, the tailor-made metalloenzymes exhibited electronically uncoupled or coupled dicopper sites. Consequently, they displayed various reactivities with dioxygen associated with multiple protons and electrons, illustrating a diverse chemical repertoire of artificial copper-dependent enzymes.