Dynamic docking assisted engineering of hydrolase for efficient PET depolymerization

Abstract

Abstract Poly(ethylene terephthalate) (PET) is the most abundant polyester plastic and is causing serious environmental pollution. Rapid biological depolymerization of PET waste at large scale requires powerful engineered enzymes with excellent performance. Here, we designed a computational strategy to analyze the ligand affinity energy of enzymes to PET chains by molecular docking with the dynamic protein conformations, named Affinity analysis based on Dynamic Docking (ADD). After three rounds of protein engineering assisted by ADD, we drastically enhanced the PET-degrading activity of leaf-branch-compost cutinase (LCC). The best variant LCC-A2 degraded >90% of the pretreated, post-consumer PET waste into corresponding monomers within 3.3 h, and over 99% of the products were terminal degradation products (terephthalic acid and ethylene glycol), representing the fastest PET degradation rate reported to date. Structural analysis revealed interesting features that improved the ligand affinity and catalytic performance. In conclusion, the proposed strategy and engineered variants represent a substantial advancement of the biological circular economy for PET.