State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Science, Jinan 250353, PR China; School of Bioengineering, Qilu University of Technology, Shandong Academy of Science, Jinan 250353, PR China.
School of Bioengineering, Qilu University of Technology, Shandong Academy of Science, Jinan 250353, PR China.
J Colloid Interface Sci. 2023 Sep 15;646:198-208. doi: 10.1016/j.jcis.2023.05.017. Epub 2023 May 9.
Polyethylene terephthalate (PET), the most abundant polyester plastic, has become a global concern due to its refractoriness and accumulation in the environment. In this study, inspired by the structure and catalytic mechanism of the native enzyme, peptides, based on supramolecular self-assembly, were developed to construct enzyme mimics for PET degradation, which were achieved by combining the enzymatic active sites of serine, histidine and aspartate with the self-assembling polypeptide MAX. The two designed peptides with differences in hydrophobic residues at two positions exhibited a conformational transition from random coil to β-sheet by changing the pH and temperature, and the catalytic activity followed the self-assembly "switch" with the fibrils formed β-sheet, which could catalyze PET efficiently. Although the two peptides possessed same catalytic site, they showed different catalytic activities. Analysis of the structure - activity relationship of the enzyme mimics suggested that the high catalytic activity of the enzyme mimics for PET could be attributed to the formation of stable fibers of peptides and ordered arrangement of molecular conformation; in addition, hydrogen bonding and hydrophobic interactions, as the major forces, promoted effects of enzyme mimics on PET degradation. Enzyme mimics with PET-hydrolytic activity are a promising material for degrading PET and reducing environmental pollution.
聚对苯二甲酸乙二醇酯（PET）是最丰富的聚酯塑料，由于其在环境中的难降解性和积累性而引起了全球关注。在这项研究中，受天然酶结构和催化机制的启发，我们基于超分子自组装开发了基于肽的酶模拟物，用于 PET 降解，通过将丝氨酸、组氨酸和天冬氨酸的酶活性位点与自组装多肽 MAX 结合来实现。这两种设计的肽在两个位置的疏水性残基存在差异，通过改变 pH 值和温度，从无规卷曲转变为β-折叠，表现出构象转变，并且催化活性遵循形成β-折叠的自组装“开关”，可以有效地催化 PET。尽管这两种肽具有相同的催化位点，但它们表现出不同的催化活性。对酶模拟物的结构-活性关系的分析表明，酶模拟物对 PET 具有高催化活性，这归因于肽形成稳定的纤维和分子构象的有序排列；此外，氢键和疏水相互作用作为主要作用力，促进了酶模拟物对 PET 降解的作用。具有 PET 水解活性的酶模拟物是一种很有前途的降解 PET 和减少环境污染的材料。
