Zhao Xinyu, Li Guoshun, Liang Shufang
State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, No. 17, Third Section of Renmin South Road, Chengdu 610041, China.
J Anal Methods Chem. 2013;2013:581093. doi: 10.1155/2013/581093. Epub 2013 Dec 26.
Affinity tags have become powerful tools from basic biological research to structural and functional proteomics. They were widely used to facilitate the purification and detection of proteins of interest, as well as the separation of protein complexes. Here, we mainly discuss the benefits and drawbacks of several affinity or epitope tags frequently used, including hexahistidine tag, FLAG tag, Strep II tag, streptavidin-binding peptide (SBP) tag, calmodulin-binding peptide (CBP), glutathione S-transferase (GST), maltose-binding protein (MBP), S-tag, HA tag, and c-Myc tag. In some cases, a large-size affinity tag, such as GST or MBP, can significantly impact on the structure and biological activity of the fusion partner protein. So it is usually necessary to excise the tag by protease. The most commonly used endopeptidases are enterokinase, factor Xa, thrombin, tobacco etch virus, and human rhinovirus 3C protease. The proteolysis features of these proteases are described in order to provide a general guidance on the proteolytic removal of the affinity tags.
亲和标签已成为从基础生物学研究到结构和功能蛋白质组学的强大工具。它们被广泛用于促进目标蛋白质的纯化和检测，以及蛋白质复合物的分离。在此，我们主要讨论几种常用的亲和或表位标签的优缺点，包括六聚组氨酸标签、FLAG标签、链霉亲和素II标签、链霉亲和素结合肽（SBP）标签、钙调蛋白结合肽（CBP）、谷胱甘肽S-转移酶（GST）、麦芽糖结合蛋白（MBP）、S标签、HA标签和c-Myc标签。在某些情况下，较大尺寸的亲和标签，如GST或MBP，会对融合伴侣蛋白的结构和生物学活性产生显著影响。因此通常需要用蛋白酶切除标签。最常用的内肽酶是肠激酶、凝血因子Xa、凝血酶、烟草蚀纹病毒和人鼻病毒3C蛋白酶。描述了这些蛋白酶的蛋白水解特性，以便为亲和标签的蛋白水解去除提供一般指导。
