Yuan Xin, Wu Xiaoling, Xiong Jun, Yan Binhang, Gao Ruichen, Liu Shuli, Zong Minhua, Ge Jun, Lou Wenyong
Lab of Applied Biocatalysis, School of Food Science and Technology, South China University of Technology, 510640, Guangzhou, Guangdong, China.
Department of Chemical Engineering, Tsinghua University, 100084, Beijing, China.
Nat Commun. 2023 Sep 25;14(1):5974. doi: 10.1038/s41467-023-41716-6.
Enzymes achieve high catalytic activity with their elaborate arrangements of amino acid residues in confined optimized spaces. Nevertheless, when exposed to complicated environmental implementation scenarios, including high acidity, organic solvent and high ionic strength, enzymes exhibit low operational stability and poor activity. Here, we report a metal-organic frameworks (MOFs)-based artificial enzyme system via second coordination sphere engineering to achieve high hydrolytic activity under mild conditions. Experiments and theoretical calculations reveal that amide cleavage catalyzed by MOFs follows two distinct catalytic mechanisms, Lewis acid- and hydrogen bonding-mediated hydrolytic processes. The hydrogen bond formed in the secondary coordination sphere exhibits 11-fold higher hydrolytic activity than the Lewis acidic zinc ions. The MOFs exhibit satisfactory degradation performance of toxins and high stability under extreme working conditions, including complicated fermentation broth and high ethanol environments, and display broad substrate specificity. These findings hold great promise for designing artificial enzymes for environmental remediation.
酶通过在受限的优化空间中精心排列氨基酸残基来实现高催化活性。然而，当暴露于复杂的环境应用场景中，包括高酸度、有机溶剂和高离子强度时，酶表现出较低的操作稳定性和活性。在此，我们报道了一种基于金属有机框架（MOF）的人工酶系统，通过二次配位球工程在温和条件下实现高水解活性。实验和理论计算表明，MOF催化的酰胺裂解遵循两种不同的催化机制，即路易斯酸介导和氢键介导的水解过程。在二次配位球中形成的氢键表现出比路易斯酸性锌离子高11倍的水解活性。MOF在包括复杂发酵液和高乙醇环境在内的极端工作条件下表现出令人满意的毒素降解性能和高稳定性，并显示出广泛的底物特异性。这些发现为设计用于环境修复的人工酶带来了巨大希望。
