Abstract: Fusion tags were effective tools for large-scale production of soluble proteins. Application of fusion tags in soluble expression has become a priority of research. This paper mainly introduced the most frequently used fusion tags，as well as the possible mechanism of their ability to enhance solubility. Five models have been employed to explain the role of fusion tags in protein folding from different aspects. Most powerful fusion tags，such as MBP and NusA，act as a general molecular chaperone to assist passenger protein folding into native conformation. Furthermore，it also provides strategies to remove fusion tags and the efficiency of proteases. At last，it elaborates their prospects and challenges faced in large-scale production of protein. This review serves as an excellent reference for those working on protein fusion tags. In view of the limitation of existing tags，our laboratory is developing a novel multifunctional fusion tag. Present study has showed that it can greatly improve soluble expression level，and further study is conducted on the purification methods and mechanism of it.

Key words: biotechnology, protein, solubility, fusion tag, recombinant protein, solubility, purification

摘要： 融合标签是大规模生产可溶性蛋白质的有效工具，因此融合标签在蛋白质可溶性表达中的应用已成为外源蛋白表达的研究热点。本文重点介绍了常用融合标签及其提高重组蛋白质可溶性表达的机理，主要用5种模型从不同的角度阐述融合标签在蛋白折叠中的作用，其中大多数功能较强的融合标签（如MBP和NusA）作为分子伴侣帮助重组蛋白正确折叠从而提高蛋白质可溶性。此外，阐述了实际应用中常用的组合标签和标签的去除。最后提出了融合标签在大规模生产可溶性蛋白质中的应用前景、面临的挑战，以及今后研究的方向。

关键词: 生物技术, 蛋白, 溶解性, 融合标签, 重组蛋白质, 可溶性表达, 纯化