Molecular Self-Assembly Strategy for Generating Catalytic Hybrid Polypeptides.
Molecular Self-Assembly Strategy for Generating Catalytic Hybrid Polypeptides.
复制标题
生成催化杂合多肽的分子自组装策略
DOI：
10.1371/journal.pone.0153700
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Matsui H
中科院分区：
文献类型：
--
作者：
Maeda Y;Fang J;Ikezoe Y;Pike DH;Nanda V;Matsui H
最近，催化肽被引入模拟蛋白酶的活性，即使在蛋白酶不能很好发挥作用的有机溶剂中也显示出良好的产物选择性。然而，与天然酶相比，它们的催化效率极低，这可能是因为缺乏稳定的三叠体。我们假设，将这些多肽与简单的疏水口袋组装在一起，模仿酶的活性部位，可以提高催化活性。在这里，我们将具有蛋白酶和酯酶样活性的催化多肽Cp4序列融合到Aβ的一个短的淀粉样蛋白多肽片段中。当融合的Cp4-Aβ结构组装成反平行的β片层和淀粉样纤维时，观察到对-硝基苯乙酸酯(p-NPA)的水解率比纯净的Cp4多肽增加了4倍。Cp4-Aβ组装体的催化活性增强既可以通过催化活性丝氨酸三联体的预组织来解释，也可以通过在三联体和对-NPA之间结合底物的疏水稳定来解释，这表明自组装肽的设计策略对于实现预期的功能是重要的。
Recently, catalytic peptides were introduced that mimicked protease activities and showed promising selectivity of products even in organic solvents where protease cannot perform well. However, their catalytic efficiency was extremely low compared to natural enzyme counterparts presumably due to the lack of stable tertiary fold. We hypothesized that assembling these peptides along with simple hydrophobic pockets, mimicking enzyme active sites, could enhance the catalytic activity. Here we fused the sequence of catalytic peptide CP4, capable of protease and esterase-like activities, into a short amyloidogenic peptide fragment of Aβ. When the fused CP4-Aβ construct assembled into antiparallel β-sheets and amyloid fibrils, a 4.0-fold increase in the hydrolysis rate of p-nitrophenyl acetate (p-NPA) compared to neat CP4 peptide was observed. The enhanced catalytic activity of CP4-Aβ assembly could be explained both by pre-organization of a catalytically competent Ser-His-acid triad and hydrophobic stabilization of a bound substrate between the triad and p-NPA, indicating that a design strategy for self-assembled peptides is important to accomplish the desired functionality.