The discovery of the mini-protease:Seryl Histidine Dipeptide
会议名称：《中国化学会第26届学术年会化学生物分会场》
会议日期：2008年
学科分类：0710[理学-生物学] 071010[理学-生物化学与分子生物学] 081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术]
关 键 词：Ser-His diepetide mini-protease cleavage selectivity evolutionary origin
摘 要：Our previous researches showed that Seryl-Histidine dipeptide (Ser-His) could cleave proteins such as bovine serum albumen (BSA) [1] and green fluorescence protein (GFP) [4] over wide ranges of pH and temperature, as well as DNA [1], with a hydrolysis mechanism. Therefore, Ser-His is the shortest peptide with the hydrolysis cleavage activity on protein, and its function is similar to serine protease. Recently, the discovery of extended substrate specificity of opossum chymase illuminated the origin of mast cell chymases [5, 6]. So, to investigate the function of Ser-His further might provide more information to understand the function group evolution for the origin of serine protease. In this paper, high resolution mass spectrometry was applied to study the cleavage sites of Seryl-Histidine dipeptide (Ser-His) on two different proteins, namely green fluorescence proteins (xm18) and cyclophilin A. It was found that the two different protein, were both cleaved by Ser-His into small polypeptide fragments. Through comparison of the cleavage activity of Ser-His and Protease K, it means that the hydrolysis activity of Ser-His is about one thirty thousandths of that of Protease K. Although Ser-His possesses non-specificity cleavage activity on the primary sequence of substrate proteins, but, amino acid residue, F, is the more favorite cleavage site (Fig. 1 and Fig. 2), which is similar to the natural serine protease, chymotrypsin. Therefore, the smallest peptide, Ser-His dipeptdie, was named the as mini-protease. It implied that Ser-His is probably the origin of serine proteases.