Download MendeleyRemodeling the polymer-binding cavity to improve the efficacy of PBAT-degrading enzyme.
Yang, Y., Cheng, S., Zheng, Y., Xue, T., Huang, J.W., Zhang, L., Yang, Y., Guo, R.T., Chen, C.C.(2023) J Hazard Mater 464: 132965-132965
- PubMed: 37979420
- DOI: https://doi.org/10.1016/j.jhazmat.2023.132965
- Primary Citation of Related Structures:
8JMO, 8JMP - PubMed Abstract:
Poly(butylene adipate-co-terephthalate) (PBAT) is among the most widely applied synthetic polyesters that are utilized in the packaging and agricultural industries, but the accumulation of PBAT wastes has posed a great burden to ecosystems. Using renewable enzymes to decompose PBAT is an eco-friendly solution to tackle this problem. Recently, we demonstrated that cutinase is the most effective PBAT-degrading enzyme and that an engineered cutinase termed TfCut-DM could completely decompose PBAT film to terephthalate (TPA). Here, we report crystal structures of a variant of leaf compost cutinase in complex with soluble fragments of PBAT, including BTa and TaBTa. In the TaBTa complex, one TPA moiety was located at a polymer-binding site distal to the catalytic center that has never been experimentally validated. Intriguingly, the composition of the distal TPA-binding site shows higher diversity relative to the one proximal to the catalytic center in various cutinases. We thus modified the distal TPA-binding site of TfCut-DM and obtained variants that exhibit higher activity. Notably, the time needed to completely degrade the PBAT film to TPA was shortened to within 24 h by TfCut-DM Q132Y (5813 mol per mol protein). Taken together, the structural information regarding the substrate-binding behavior of PBAT-degrading enzymes could be useful guidance for direct enzyme engineering.
Organizational Affiliation:
State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Hongshan Laboratory, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, 430062 Wuhan, People's Republic of China.
