摘要： 白眉蝮蛇降纤酶是我国在临床上用来治疗血栓栓塞性疾病的国家基本药物。但该酶来源于蛇毒,是异源蛋白,且是大分子蛋白质,不可避免的存在免疫原性问题。另外该蛋白药物在我国使用规模很大,因此由免疫原性导致的安全性问题不容忽视。首先通过DNAStar软件和ABCpred、BCPREDS等服务器预测得到肽端AA27~35、44~50、66~72、79~98、101~109、117~127、134~142、151~164、179~188、194~206、221~233、247~260区域为白眉蝮蛇降纤酶的B细胞线性表位优势区域。然后以蝮蛇毒蛋白C激活剂蛋白的晶体结构为模板,利用MODELLER 9.10软件中的Pythonwin程序进行白眉蝮蛇降纤酶的同源模建,并利用PROCHECK、ERRAT及PROSA程序进行同源模建的合理化评价。根据白眉蝮蛇降纤酶的模建三维结构并结合DiscoTope和consPPISP网络数据库预测B细胞构象型抗原表位。得到蛋白的N端45~51、81~90、95~106、134~141、153~159、177~182、225~232、251~257区段为白眉蝮蛇降纤酶的B细胞构象型表位区域。本项目的预期成果将为降纤酶药物的安全化应用提供新思路,为蛋白质药物免疫原性机制研究提供技术基础。

关键词: 降纤酶, 免疫原性, 线性表位, 构象型表位, 同源模建, 长白山白眉蝮蛇

Abstract: Defibrase from Agkistrodou halys ussurieusis snake venom is essential medicine to be used in the clinical treatment of thromboembilic disease in our country. However, this enzyme derived from snake venom, is a heterologous protein and is a macromolecular protein,and therefore,it's immunogenicity problem is inevitable. Moreover this protein drug was used in large scale in our country and therefore,the security issues caused by immunogenicity cannot be ignored. In this work B cell linear epitopes were predicted using DNAStar soft ware and ABCpred,BCPREDS BcePred,B epiPred 1 .0 and Ellipro web servers. Bell linear epitopes in defibrase were predicted to locate in the regions of 27一35,44一50,66一72,79一98,101一109,117一127,134一142 151一164,179一188,194-206,221一233 and 247一260. Using protein C activator from Agkistrodou coutortrix venom (ACCT) as template,a 3D structure model of defibrase was constructed by Pythonwin program using modeling package MODELLER 9. 10. Stereochemical quality of the selected model was evaluated using PROCHECK, Errat and PROSA programs. The conformational epitopes of defibrase was predicted by 3 D structure of homology modeling combined with Discotope 1.2 server and cons PPISP online tools. Bell conformational epitopes in defibrase were predicted to locate in the regions of 45一51,81一90,95一106,134一141,153一159,177一182 225一232 and 251一257. The expected results of the project are useful for providing new ideas for the safety applications of defibrase drugs and providing the technical basis for immunogenicity mechanism of protein drugs.

Key words: Defibrase, Immunogenicity, Linear epitopes, Conformational eptiopes, Homology modeling, Agkistroddon halys ussuriensis

中图分类号: 

• R34