丙型肝炎病毒E1蛋白的模拟表位研究

Studies on mimotopes of hepatitis C virus E1 protein

目的研究ＨＣＶ Ｅ１蛋白的Ｂ－细胞表位。方法将携带ＨＣＶ Ｅ１基因的重组质粒ｐＱＥ－３０－ ＨＣＶｅ１１８在Ｅ．ｃｏｌｉ Ｍ１５中进行大量诱导、表达；对表达的Ｅ１蛋白进行分离、纯化；再以纯化的蛋白捕获ＨＣＶ感染者血清中能与 ＨＣＶ Ｅ１蛋白特异反应的 ＩｇＧ，以此 ＩｇＧ作为筛选分子，对随机十二肽库进行淘洗，经 ＥＬＩＳＡ筛选噬菌体阳性克隆并测序。结果ＨＣＶ Ｅ１蛋白获得了高纯度的纯化，这种蛋白可特异地与部分丙型肝炎患者血清发生反应。在获得的 １０个模拟表位中， ６、 ２和２个递呈肽分别与 ＨＣＶ Ｅ１蛋白的３２０～３３６ａａ、 ２５１～２６３ａａ和２２５～２４８位ａａ具有最大同源性。结论在Ｅ１蛋白中存在多个Ｂ－细胞表位，３２０－３３６位极可能为ＨＣＶ Ｅ１蛋白的优势表位。

Objective To study the B-cell epitope of E1 protein of hepatitis C virus. Methods By induction of IPTG, the E.goli M15 strains harboring the pQE30-HCVe118 expressed truncated C-terminal HCV E1 protein (Pte1). The proteins were purified with preparative electrophoreses system, which captured anti-E1 IgG in HCV (+) sera. By applying the antibodies as selective molecular 12 iners random peptide libraries were panned, and positive clones were obtained by ELISA. Amino acid sequences of display peptide were compared with that of HCV EI protein. Results The purified HCV E1 proteins could react specifically with patly anti-HCV sera by ELISA. Among 10 phage display peptides, 6, 6, 2 were the most homologous to HCV E1 Protein at position 320-336aa, 251-263aa, 225-248, respectively.Conclusions There exist multiple B-cell epitopes in HCV E1 protein. At least one preponderant epitope is mapped at residues 320-336 of HCV E1 protein.