利用细菌鞭毛展示的随机肽库筛选HBV-PreS2蛋白表位

目的：建立、改进并完善从细菌表面展示随机肽库中进行抗原表位筛选及鉴定的方法。方法：以1株抗HBV-PreS2的单克隆抗体3B9为靶标,对FliTrx^TM随机肽库进行筛选;监测每轮与抗体特异性结合的细菌克隆富集情况;通过逐轮增加洗涤强度筛选高亲和力克隆;对筛选出的克隆进行序列测定和Western blot鉴定。结果：筛选过程中与抗体特异性结合的细菌克隆逐轮得到富集,对16个克隆进行序列测定,共获得10种序列,其中7个序列含典型的RXR(K)GXY保守序列,与病毒PreS蛋白135-140位氨基酸高度同源,Western blot反应为阳性;另外3个序列均不含典型的RXR(K)GXY结构,Western blot反应结果不一。结论：细菌表面展示的随机肽库是一种简捷、快速的抗原表位筛选方法。

Isolation of a HBV-PreS2 epitope from a random peptide library displayed on the bacterial flagellin

OBJECTIVE: To establish an improved procedure for isolation and identification of epitopes from a random peptide library displayed on the bacterial surface. METHODS: Epitopes were screened from FliTrx random peptide library by a monoclonal antibody 3B9 against HBV-PreS2 protein. The enrichment was monitored in each round. Higher affinity clones were obtained by increasing the washing strength and randomly selected for sequencing and Western blot analysis. RESULTS: Clones specifically binding to antibody were enriched in each round. Ten sequences were obtained from sixteen sequenced clones, seven of them contained the common motif RXRGXY with high homogeneity to 135-140 amio acids in HBV-PreS protein and have positive results in Western blot analysis. The other three sequences have no typical motif RXRGXY and showed different Western blot results. CONCLUSIONS: It's easy and quick to drive epitopes from a random peptide library displayed on the bacterial surface.