鼠伤寒脂多糖表位模拟位的筛选  

Screening of mimotope of Salmonella typhimurium lipopolysaccharide from phage-displayed peptide

作　　者：郑山根[1] 朱平[1] 刘北一[1] 富宁[1] 

机构地区：[1]第一军医大学免疫教研室,广东广州510515

出　　处：《第一军医大学学报》2003年第2期118-120,123,共4页Journal of First Military Medical University

基　　金：国家自然科学基金(30070769)~~

摘　　要：目的获得模拟脂多糖抗原表位的噬菌体环状展示肽.方法用抗鼠伤寒菌脂多糖单克隆抗体2F4为靶分子,亲和筛选噬菌体随机环七肽库,双夹心ELISA及特异性抗原抑制试验鉴定阳性克隆.结果经三轮筛选,随机挑选38个克隆,其中34个克隆显示与2F4结合.鼠伤寒沙门氏菌脂多糖可抑制噬菌体克隆与2F4结合,所有克隆的半数抑制浓度为(0.125～0.250)μg/ml.挑选10个克隆测序并推导氨基酸序列,其中7个克隆出现P-X-WAS-X-W保守序列;10个序列中非极性氨基酸含量平均值为71.4%.结论噬菌体展示环七肽可模拟鼠伤寒沙门氏菌脂多糖抗原表位.Objective To identify and characterize the mimotope of lipopolysaccharide (LPS) from cyclic 7-mer phage peptide library. Methods Cyclic 7-mer phage-displayed peptide library was screened using monoclonal antibody 2F4 (mAb 2F4) against Salmonella typhimurium LPS as the target, and the selected clones were tested by sandwich enzyme-linked immunosorbent assay (ELISA) and specific antigen inhibition ELISA. Results After 3 round of screening, 34 of the 38 selected clones were identified as positive for binding to mAb 2F4. Salmonella typhimurium LPS was capable of inhibiting the binding between the cones and mAb 2F4, with the 50% inhibitory concentration of all the positive clones within the range of 0.125-0.250 μg/ml. Sequence analysis was performed for 10 of the positive clones, whose amino acid sequences were subsequently deduced, and 7 of them had conservative amino acid of P-X-WAS-X-W with the mean hydrophobic amino acid content of 71.4% in all the sequences. Conclusion The phage-displayed peptide is capable of simulating the epitope of Salmonella typhimurium LPS.

关 键 词：脂多糖 筛选 噬菌体 内毒素休克 抗体 鼠伤寒沙门氏菌 

分 类 号：R392[医药卫生—免疫学]