Proteins, which exist mainly in linear form in vivo, are easily affected by the change of ambient temperature and pH. The application of proteins (enzymes) in the fields of industrial catalyzing, food manufacturing and medicine are restricted due to their properties. The cyclic structure of natural cyclic peptides confers high thermal stability on itself; such mechanism can be referred to in further enhancement of the thermal stability and transformation of the structure of enzymes. This article reviewed the latest progress in the domestic and international studies on protein cyclization and summarized the traditional methods (such as protein trans-splicing, expressed protein ligation and sortase-catalyzed transpeptidation) in protein cyclization. A novel method based on SpyTag/SpyCather-mediated enzyme cyclization was discussed in more detail.
天然蛋白质在生物体内主要以线性形式存在，由于多数蛋白质 (酶) 热稳定性较差，制约了其在工业催化、食品制造、医药领域的高效应用。自然界中发现的天然环肽类物质具有首尾相连的环化结构，使蛋白质具有较高的稳定性，为改造酶的结构、提高其热稳定性及拓宽其应用范围提供了新思路。本文根据国内外在蛋白质环化领域的新动态并结合本实验室的研究，系统介绍了内含肽介导的蛋白质反式剪接、表达蛋白连接、转肽酶催化的转肽作用等几种传统蛋白质环化方法，着重介绍了基于新型超强分子粘合剂SpyTag/SpyCatcher 介导的蛋白质环化的研究。.
Keywords: SpyTag/SpyCatcher; expressed protein ligation; photocontrol intein; protein trans-splicing; sortase-catalyzed transpeptidation.