应用噬菌体展示随机12肽库筛选诺如病毒抗原模拟表位

Screening antigen mimic epitope of Norovirus by phage random 12-peptidelibrary

目的:利用Ph.D.-12噬菌体展示肽库筛选诺如病毒(NoV)的抗原模拟表位。方法:包被与GⅡ.4、GⅡ.6、GⅡ.17型NoV具有高特异性及中和能力较强的单链可变片段抗体(scFv),用Ph.D.-12噬菌体展示肽库进行3轮生物淘选。ELISA鉴定淘选所得噬菌体与scFv的结合活性及其与NoV P蛋白的竞争作用;阳性克隆测序后进行生物信息学分析,合成多肽鉴定其抗原性。结果:发现1段与GⅡ.6 VP1区同源性较高的氨基酸序列“MG-D-W”,综合分析提示其可能为GⅡ.6 NoV的抗原模拟表位,且合成的包含“MG-D-W”的多肽可竞争抑制P蛋白与人类组织血型抗原(HBGAs)受体的结合。结论:“MG-DW”是与NoV单链抗体高亲和力的肽段,可能模拟了GⅡ.6 NoV与scFv结合的抗原表位。

Objective:To screen mimic epitope of Norovirus(NoV)by Ph.D.-12 phage display peptide library.Methods:Sin-gle-chain variable fragment antibody(scFv)with high specificity and neutralizing ability against GⅡ.4/GⅡ.6/GⅡ.17 NoV were coated and screened for 3 rounds with Ph.D.-12 phage library.ELISA was used to identify binding activity of phage with scFv and its competi-tion with NoV P protein.Positive clones were sequenced and bioinformatic analysis was performed,antigenicity was identified by syn-thetic peptides.Results:A sequence was found to be with highly homologous to GⅡ.6 VP1 region:MG-D-W,suggesting that it was a specific epitope of GⅡ.6 NoV.Peptide containing"MG-D-W"was further synthesized,which could competitively inhibit binding of P protein to HBGA receptor.Conclusion:MG-D-W is a peptide with high affinity for NoV scFv and likely mimics antigenic epitope of GⅡ.6 NoV bound to scFv.