State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin 300457, P. R. China.
School of Food Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Ji'nan, Shandong 250353, P. R. China.
J Mater Chem B. 2020 Oct 28;8(41):9601-9609. doi: 10.1039/d0tb01931c.
Enzyme mimics have been developed by imitating and incorporating specific features of native enzymes to achieve catalytic activity, and are expectedly comparable to that of native enzymes. Here, inspired by the "catalytic triad" in serine proteases, a series of peptide-based enzyme mimics were designed to follow the rational design principle of peptides via self-assembly, and were further applied in the degradation of di(2-ethylhexyl)phthalate (DEHP). The relationship of the structure of enzyme mimics with their degradation activity was analyzed by transmission electron microscopy, fluorescence spectroscopy, circular dichroism, Raman spectroscopy, X-ray diffraction spectroscopy, and computational modeling. These results show that the hydrophobic skeleton, amino acid sequence, species, and periodic distribution have important effects on the structure of the peptide sequence and the number of hydrogen bonds; in addition, pH can also affect the self-assembly characteristics of peptides and the formation of stable fibers, which are all closely linked to the catalytic activity of the enzyme mimics. The self-assembled peptides had a stable fibrous morphology and secondary structure after the DEHP degradation assay. The enzyme mimics with high catalytic activity constructed from the self-assembled peptides may provide guidance for the future degradation of DEHP in food packaging or water treatment, and also give insights into the design of enzyme mimics in other related fields.
酶模拟物通过模仿和整合天然酶的特定特征来实现催化活性，并且可以预期与天然酶相当。在这里，受丝氨酸蛋白酶“催化三联体”的启发，设计了一系列基于肽的酶模拟物，通过自组装遵循肽的合理设计原则，并进一步应用于邻苯二甲酸二(2-乙基己基)酯 (DEHP) 的降解。通过透射电子显微镜、荧光光谱、圆二色性、拉曼光谱、X 射线衍射光谱和计算建模分析了酶模拟物的结构与其降解活性之间的关系。这些结果表明，疏水性骨架、氨基酸序列、种类和周期性分布对肽序列的结构和氢键的数量有重要影响；此外，pH 值也会影响肽的自组装特性和稳定纤维的形成，这与酶模拟物的催化活性密切相关。自组装肽在 DEHP 降解试验后具有稳定的纤维形态和二级结构。由自组装肽构建的具有高催化活性的酶模拟物可能为未来食品包装或水处理中 DEHP 的降解提供指导，也为其他相关领域的酶模拟物设计提供了思路。
