Making and breaking peptide bonds: protein engineering using sortase

Sortases are a class of bacterial enzymes that possess transpeptidase activity. It is their ability to site-specifically break a peptide bond and then reform a new bond with an incoming nucleophile that makes sortase an attractive tool for protein engineering. This technique has been adopted for a range of applications, from chemistry-based to cell biology and technology. In this Minireview we provide a brief overview of the biology of sortase enzymes and current applications in protein engineering. We identify areas that lend themselves to further innovation and that suggest new applications.     

Sortase-Mediated Transpeptidation for Site-Specific Modification of Peptides,Glycopeptides, and Proteins

Sortases are a family of transpeptidases found in gram-positive bacteria responsible for covalent anchoring of cell surface proteins to bacterial cell walls. It has been discovered that sortase A (SrtA) of Staphylococcus aureus origin is rather promiscuous and can accept various molecules as substrates. As a result, SrtA has been widely used to ligate peptides and proteins with a variety of nucleophiles, and the ligation products are useful for research in chemical biology, proteomics, biomedicine, etc. This review summarizes the recent applications of SrtA with special emphasis on SrtA-catalyzed ligation of carbohydrates with peptides and proteins.     

转肽酶Sortase A在蛋白质修饰中的应用

近年来,发展蛋白质与多肽的化学选择性连接与修饰方法已成为化学生物学的研究热点。这类方法可以在很大程度上弥补基因工程技术无法制备翻译后修饰蛋白与人工改造蛋白的缺陷,得到目前无法通过生物表达的功能蛋白。20世纪90年代末,人们从金黄色葡萄球菌中分离得到转肽酶Sortase A,它能够选择性识别特异性多肽序列LPXTG,并在特定位点切断氨基酸的肽键进而将其与一个新的肽链连接。该特性使Sortase A有望成为一种高效、通用的蛋白质修饰的工具。与传统的化学合成相比,Sortase催化的化学半合成方法,可以较好的解决化学合成蛋白的尺寸问题。本文就近年来Sortase A在蛋白质修饰及合成中的研究进展进行简要综述。