DataSheet1_Molecular and Biochemical Differences of the Tandem and Cold-Adapted PET Hydrolases Ple628 and Ple629, Isolated From a Marine Microbial Consortium.pdf

Polybutylene adipate terephthalate (PBAT) is a biodegradable alternative to polyethylene and can be broadly used in various applications. These polymers can be degraded by hydrolases of terrestrial and aquatic origin. In a previous study, we identified tandem PETase-like hydrolases (Ples) from the marine microbial consortium I1 that were highly expressed when a PBAT blend was supplied as the only carbon source. In this study, the tandem Ples, Ple628 and Ple629, were recombinantly expressed and characterized. Both enzymes are mesophilic and active on a wide range of oligomers. The activities of the Ples differed greatly when model substrates, PBAT-modified polymers or PET nanoparticles were supplied. Ple629 was always more active than Ple628. Crystal structures of Ple628 and Ple629 revealed a structural similarity to other PETases and can be classified as member of the PETases IIa subclass, α/β hydrolase superfamily. Our results show that the predicted functions of Ple628 and Ple629 agree with the bioinformatic predictions, and these enzymes play a significant role in the plastic degradation by the consortium.

聚己二酸-对苯二甲酸丁二醇酯（Polybutylene adipate terephthalate, PBAT）是聚乙烯的可生物降解替代品，可广泛应用于诸多领域。这类聚合物可被陆生及水生来源的水解酶降解。在前期研究中，我们从海洋微生物群落I1中鉴定得到串联型类PET水解酶（PETase-like hydrolases, Ples）；当以PBAT共混物作为唯一碳源时，这类酶呈现高表达水平。本研究中，我们对两种串联型Ples——Ple628与Ple629进行了重组表达与功能表征。两种酶均为嗜温酶，可对多种寡聚物展现催化活性。当使用模型底物、PBAT改性聚合物或PET纳米颗粒作为底物时，两种Ples的活性差异显著。Ple629的催化活性始终高于Ple628。Ple628与Ple629的晶体结构显示，二者与其他PET水解酶（PETase）具有结构相似性，可归类为PET水解酶IIa亚类、α/β水解酶超家族成员。本研究结果表明，Ple628与Ple629的推定功能与生物信息学预测结果一致，且这两种酶在该菌群介导的塑料降解过程中发挥了重要作用。