胰凝乳蛋白酶短肽抑制剂的筛选和活性分析  

Selection and Characterization of Chymotrypsin Peptide Inhibitors

作　　者：刘莹[1] 张姝[1] 李天羽 范洪宽[1] 周慧[1] 李惟[1] 

机构地区：[1]吉林大学生命科学学院

出　　处：《中国生物化学与分子生物学报》1999年第2期296-299,共4页Chinese Journal of Biochemistry and Molecular Biology

基　　金：国家自然科学基金

摘　　要：报道了一种从噬菌体肽库中筛选胰凝乳蛋白酶短肽抑制剂的新方法．在通常的亲和富集筛选的基础上，利用胰凝乳蛋白酶自身的水解活力切割掉结合的底物噬菌体，再经抑制活力分析得到抑制性噬菌体克隆．这样筛得的噬菌体克隆具有明显的胰凝乳蛋白酶结合活力和抑制活力，ＤＮＡ序列分析发现其保守序列为（Ｓ／Ｔ）ＲＶＰＲ（Ｒ／Ｈ）．按此序列化学合成的短肽Ａｃ－ＡＳＲＶＰＲＲＧ－ＮＨ２、Ａｃ－ＡＳＲＶＰＲＨＧ－ＮＨ２同样表现出对胰凝乳蛋白酶的抑制作用．Random peptide library displayed on the surface of filamentous phage has been used successfully to identify peptide ligands that bind to various molecules.But in the case of proteinase inhibitors,the usual affinity selection method is unable to distinguish inhibitors from other peptide ligands.Therefore,a new strategy was developed and used to identify α chymotrypsin inhibitors.It modified the standard affinity selection protocol by adding a proteolytic cleavage period to avoid recovery of substrate phage.Then,inhibitory assays were performed to identify active phage clones.Finally,a consensus sequence motif (S/T)RVPR(R/H)was revealed by DNA sequencing,sharing common features with some natural chymotrypsin inhibitors in two or three positions.In further study,the binding abilities and inhibitory activities of six sequenced phage clones were measured.No obvious correlation was observed between these two properties.According to the sequences of phage with high inhibitory activity,two peptides Ac ASRVPRRG NH 2,Ac ASRVPRHG NH 2 were synthesized and proved to be inhibitors of α chymotrypsin.The presented work provides a useful way of searching for short peptide inhibitors of proteinases.

关 键 词：胰凝乳蛋白酶 抑制剂 肽库 噬菌体 筛选 

分 类 号：Q516[生物学—生物化学] Q78