解聚
化学
聚对苯二甲酸乙二醇酯
催化作用
化学工程
材料科学
高分子科学
高分子化学
有机化学
复合材料
工程类
作者
Mingna Zheng,Yanwei Li,Ruisong Xue,Weiliang Dong,Qingzhu Zhang,Wenxing Wang
标识
DOI:10.1016/j.jclepro.2022.134429
摘要
Enzymatic depolymerization has become an increasingly important solution to PET pollution. However, the understanding of depolymerization reaction mechanism of environment-relevant PET waste and the influence of PET size on the depolymerization efficiency are still insufficient. In this work, the nanosized model substrate was used to systematically explore environment-relevant PET depolymerization process with the aid of quantum mechanics/molecular mechanics (QM/MM) techniques. The results supported that the depolymerization process of nanosized PET debris was similar with the routinely used model substrate (PET dimer). However, the enzymatic energy landscape was significantly changed and step iii became the rate-determining step for both Is PETase and LCC ICCG with the Boltzmann-weighted average barriers of 15.0 and 12.3 kcal/mol, respectively. The relationships between PET binding position, PET size, and activation energies were further elucidated. This “size effect” was also verified by enzyme kinetic experiments. The influences of “size effect” on depolymerization activity were clarified through hydrogen bond network and distortion/interaction analysis. In addition, the relationship between active site features and activation energy barrier was established. These molecular insights will offer a key basis for rational enzyme engineering strategy to remove PET in a more environmentally friendly and efficient way. • l Substrate size influences enzymatic PET depolymerization efficiency. • l Favorable nanosized PET binding model was screened and clarified. • l Origin of the size effect was revealed through experimental and theoretical methods. • l Correlations between feature and efficiency show potential engineering strategies.
科研通智能强力驱动
Strongly Powered by AbleSci AI