An efficient artificial esterase with a dynamic conformation via conformational engineering

The catalytic turnover number ( k _cat ) 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 k _cat 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.