应用噬菌体肽库筛选胃癌相关抗原模拟表位

Selection of mimic epitope of gastric cancer associated antigen by using phage peptide library

目的 利用噬菌体递呈随机肽文库筛选技术 ,进行胃癌相关抗原 MG7Ag模拟表位的研究 .方法 应用离子交换层析法从小鼠腹水中纯化抗胃癌单克隆抗体 MG7m Ab,细胞 EL ISA方法检测其活性 .以 MG7m Ab作为筛选分子 ,生物淘洗噬菌体递呈随机 7肽文库 .经 3次淘洗后将筛选所得的噬菌体克隆进行 DNA测序 ,递呈随机 7肽氨基酸序列同源性分析 .结果 对阳性噬菌体进行递呈肽氨基酸序列分析 ,获得一侯选模拟表位 (KPHx Hx H) .结论 经过对随机 7肽库的生物淘洗 ,获得一侯选胃癌相关抗原模拟表位 。

AIM To select mimic epitope of gastric cancer associated antigen by using phage display peptide library. METHODS ①Anti gastric cancer monoclonal antibody MG 7 Ab was purified from mouse ascites fluid using ion exchange chromatography method. ②Biopanning of phage display peptide library. By using the MG 7 Ab as selective molecular, a 7 meres phage display peptide library was biopanned, and the positive clones were selected. ③Identification of the epitope: the positive clones were confirmed by DNA sequencing, amino acid sequence assay. RESULTS Twelve positive clones were chosen and a candidate epitope (KPHxHxH) was identified by amino acid sequence assay. CONCLUSION A candidate mimic epitope of gastric cancer associated antigen can be selected, thus providing the potential for developing tumor peptide vaccine.