An efficient artificial esterase with a dynamic conformation via conformational engineering

The catalytic turnover number (kcat) of current enzyme mimics and de novo designed enzymes is still orders of magnitude lower than that of natural enzymes, because mimicking the fast-dynamic feature of enzyme active centers remains a great challenge. Herein, we created a gold nanoparticle-based artificial esterase, Goldenzyme, by conformational engineering to reconstruct dynamic active centers resembling that of α-chymotrypsin. NMR characterization shows that Goldenzyme possesses a fast-dynamic feature, about 6-fold faster than typical α-helix. Therefore, Goldenzyme efficiently hydrolyzes p-nitrophenyl acetate with a net kcat of 6.37 s-1 per active center, more than 5-fold of that of α-chymotrypsin (1.19 s-1), and Goldenzyme can even hydrolyze some non-activated esters that α-chymotrypsin cannot. Our conformational engineering approach demonstrates the possibility of creating artificial enzymes that surpass natural ones.