多肽融合标签的移除策略

多肽融合标签能够赋予目标蛋白新的特性，便于目标蛋白的定位、追踪、纯化以及结构和相互作用研究．但在很多情况下，尤其是研究蛋白质结构或分离纯化药用蛋白时，需要将多肽融合标签从融合蛋白上切除，以降低和消除多肽融合标签对目标蛋白结构和功能的影响．可用来切除多肽融合标签的方法主要有4种，即化学法、内切蛋白酶法、外切蛋白酶法以及自我剪切法．介绍和比较了每种方法的基本原理、应用以及研究进展．

Current Strategies for Polypeptide Fusion Tags Removal

Using gene fusion technology, polypeptide fusion tags can be engineered into target proteins at the genetic level. The resultant recombinant proteins may possess the biochemical properties of the imported fusion tags. Therefore, it is possible to take advantage of fusion tags to improve and evaluate protein expression, to detect and track protein targets, and to purify and characterize proteins. However, it is necessary to eliminate any influence of the fusion tag in structural characterization experiments or in isolating pharmaceutical proteins. Scientists must therefore remove fusion tags prior to structural and functional analyses when fusion tags are suspected of interfering with the biological activity of a protein or influencing its behavior. The fusion tag can be removed by several methods including harsh chemical treatment, mild enzymatic cleavage by endoprotease or exoprotease, and intein-mediated self-cleavage. Here the literature is reviewed in relation to principles, applications, and approaches of each method.