A number of simple oligopeptides have been recently developed as minimalistic catalysts for mimicking the activity and selectivity of natural proteases. Although the arrangement of amino acid residues in natural enzymes provides a strategy for designing artificial enzymes, creating catalysts with efficient binding and catalytic activity is still challenging. In this study, we used the polyproline scaffold and designed a series of 13-residue peptides with a catalytic dyad or triad incorporated to serve as artificial enzymes. Their catalytic efficiency on ester hydrolysis was evaluated by ultraviolet–visible spectroscopy using the p-nitrophenyl acetate assay, and their secondary structures were also characterized by circular dichroism spectroscopy. The results indicate that a well-formed polyproline II structure may result in a much higher catalytic efficiency. This is the first report to show that a functional dyad or triad engineered into a polyproline helix framework can enhance the catalytic activity on ester hydrolysis. Our study has also revealed the necessity of maintaining an ordered structure and a well-organized catalytic site for effective biocatalysts.

中文翻译：

---

聚脯氨酸基酯水解催化剂的设计

最近开发了许多简单的寡肽作为模拟天然蛋白酶的活性和选择性的简约催化剂。尽管天然酶中氨基酸残基的排列为设计人工酶提供了策略，但创造具有有效结合和催化活性的催化剂仍然具有挑战性。在本研究中，我们使用聚脯氨酸支架并设计了一系列13个残基的肽，其中掺入催化二联体或三联体作为人工酶。使用对硝基苯乙酸酯测定法通过紫外-可见光谱评估了它们对酯水解的催化效率，并且还通过圆二色光谱表征了它们的二级结构。结果表明，良好形成的聚脯氨酸 II 结构可能会导致更高的催化效率。这是第一份表明将功能性二联体或三联体工程化到聚脯氨酸螺旋框架中可以增强酯水解催化活性的报告。我们的研究还揭示了有效生物催化剂维持有序结构和组织良好的催化位点的必要性。