Wang Ningru, Li Yanwei, Zheng Mingna, Dong Weiliang, Zhang Qingzhu, Wang Wenxing
Environment Research Institute, Shandong University, Qingdao, 266237, PR China.
Environment Research Institute, Shandong University, Qingdao, 266237, PR China.
Chemosphere. 2025 Mar;372:144108. doi: 10.1016/j.chemosphere.2025.144108. Epub 2025 Jan 15.
Polyethylene terephthalate (PET) waste significantly contributes to the global plastic crisis, but enzymatic conversion has become an efficient and environmentally friendly strategy to combat it. Therefore, this study explored the Re-face selective depolymerization mechanisms of a novel PET-degradation peptidase, hydrolase 202. Theoretical calculations revealed that the first step, a catalytic triad-assisted nucleophilic attack, is the rate-determining step. The corresponding Boltzmann-weighted average barrier was 21.6 kcal/mol. Furthermore, hydrolase 202 degraded Re-face PET more effectively than FAST-PETase, whereas other reported PET hydrolases (e.g., FAST-PETase) degraded Si-face PET more effectively. The hydrogen bond network significantly influenced the depolymerization efficiency. We also identified correlations between 24 important structural and charge features and energy barriers. Key charge, distance, and angle features were responsible for the superiority of the Re-face depolymerization. Finally, we identified residues that may affect the depolymerization efficiency of hydrolase 202, such as Glu215. These findings offer new insights into the potential engineering of PETases and may enhance enzymatic PET waste recycling.
聚对苯二甲酸乙二酯（PET）废料对全球塑料危机的加剧起到了显著作用，但酶促转化已成为应对这一危机的一种高效且环保的策略。因此，本研究探讨了一种新型PET降解肽酶——水解酶202的Re面选择性解聚机制。理论计算表明，第一步，即催化三联体辅助的亲核攻击，是速率决定步骤。相应的玻尔兹曼加权平均势垒为21.6千卡/摩尔。此外，水解酶202降解Re面PET的效果比FAST-PETase更好，而其他已报道的PET水解酶（如FAST-PETase）降解Si面PET的效果更佳。氢键网络对解聚效率有显著影响。我们还确定了24个重要的结构和电荷特征与能垒之间的相关性。关键的电荷、距离和角度特征决定了Re面解聚的优势。最后，我们确定了可能影响水解酶202解聚效率的残基，如Glu215。这些发现为PET酶的潜在工程改造提供了新的见解，并可能提高酶促PET废料回收利用的效率。
