Work

Computational loop reconstruction based design of efficient PET hydrolases

Year: 2025

Type: article

Abstract: Enzymatic PET depolymerization represents a promising approach for establishing a circular economy for PET plastics. Nonetheless, limitations in enzyme activity persist as significant challenges to its industrial application. In this research, the backbone structure of the β6-β7 loop for PET hydrolase Bhr-PETase derived from the thermophilic bacterium HR29 was reconstructed by introducing double mutations (H218N/F222M), resulting in variant Bhr-NMT with high thermal stability (Tm = 92.9 °C) and 87% increase in activity. Moreover, the loop reconstruction mutations are transplanted into the engineered PET hydrolases LCC-ICCG and Kubu-PM12, resulting variants LCC-ICCG-NM (Tm = 92.4 °C) and Kubu-PM12-NM (Tm = 92.9 °C). Under high substrate concentration (165 g kg−1) and an enzyme loading of 0.5 mgenzyme gPET−1, the designed variants Bhr-NMT, LCC-ICCG-NM, and Kubu-PM12-NM achieve an overall conversion of 93%, 90%, and 94%, respectively, outperforming the benchmark LCC-ICCG (85%). Notably, under reduced enzyme loading (0.3 mgenzyme gPET−1), Kubu-PM12-NM still reaches an overall conversion of 91%, which is significantly superior to benchmarks Kubu-PM12 (83%) and LCC-ICCG (71%). Overall, the engineered PET hydrolases demonstrate significant potential for industrial PET waste recycling. Computational loop reconstruction guided design of highly efficient PET hydrolases sheds light on the industrial recycling of PET plastics.

Source: Communications Biology

DOI: 10.1038/s42003-025-08364-6