酶的寡聚结构与催化稳定性

酶的结构与催化稳定性是生物催化与转化过程中的研究热点之一。与单体酶相比，寡聚酶在进化过程中亚基之间的聚合使其在结构和功能上具有一定的优越性，然而寡聚酶独特的四级结构导致其在制备和应用中存在诸多问题，如制备效率低、催化位点利用率低、催化稳定性差等，其中亚基解离导致的催化稳定性问题在很大程度上限制了其工业化应用。目前，介质工程、多亚基固定化、亚基界面工程和融合蛋白策略被应用于寡聚酶的催化稳定性改造，而寡聚酶至单体酶的改造策略则试图从根本上解决寡聚酶的制备和应用问题，具有较好的应用前景。本文介绍了酶的寡聚结构演替所产生的新功能，总结了寡聚酶在制备和应用中存在的问题，重点阐述了提高寡聚酶制备效率和催化稳定性的策略。

Oligomeric structure of enzyme and its catalysis stability

The structure and catalytic stability of enzymes are of intriguing interest in biocatalysis and biotransformation. Compared with monomeric enzymes, the subunit self-assembling of oligomeric enzymes brings superior structural and functional properties. However, a series of problems also exist in the course of preparation and application of oligomeric enzymes, such as poor preparation efficiency, lower utilization of catalytic sites and less catalytic stability. Among them, the weak catalytic stability resulting from subunits dissociation severely limits the wider industrial applications of oligomeric enzymes. Currently, medium engineering, multi-subunit immobilization, subunit interface engineering and fusion protein strategy have been used to improve the oligomeric enzyme stability. Besides, the design strategy of transforming oligomeric enzymes into monomers attempts to solve the preparation and application problems fundamentally and has an extensive application prospect. In this paper, the desirable functions generated by oligomeric enzyme evolution were introduced first. Then, the preparation and application problems were summarized. At last, the strategies for improving oligomeric enzyme preparation and stabilization were reviewed.