人α—干扰素与乙型肝炎病毒前S2嵌合蛋白的表达？…

目的 重组表达人α－干扰素与乙型肝炎病毒前Ｓ２融合蛋白（ＩＦＮ－Ｐｒｅ Ｓ２），探索治疗ＨＢＶ感染的特异性免疫药物。方法 采用聚合酶链反应（ＰＣＲ０技术扩增出人ＩＦＮ－α２ｂ和ＨＢＶ Ｐｒｅ Ｓ２基因片段，分步克隆获取融合基因，构建ｐＢＶ－ＩＦＮ－Ｐｒｅ Ｓ２重组表达载体，转化Ｅ．ｃｏｌｉ后诱导表达ＩＦＮ－Ｐｒｅ Ｓ２融合蛋白。结果 在Ｅ．ｃｏｌｉ中表达了相对分子质量为２７０００的目标蛋白，后者以

Expression, purificationand identification of human IFN-

OBJECTIVE: To express a fusion protein of human interferon-a2b and HBV Pre S2 in E.coli for the purpose of investigating anti-HBV immunomodulatory protein. METHODS: Human interferon-a2b and HBV Pre S2 encoding genes were amplified from plasmid templates through PCR, then fused and cloned into plasmid pBV220 through engineering technique to generate expression plasmid pBV-IFN-Pre S2. The plasmid was transfected into E. coli to produce fusion protein. RP-HPLC and ion-exchange chromatography were employed to purify fusion protein. RESULTS: 27 kDa fusion protein was expressed up to 15% of total bacterial protein in E. coli. After purification, the purity of fusion protein reached 95% of total protein. Anti-viral assay showed that IFN-Pre S2 protein induced a VSV-resistant activity of 1.25 x 10(8) lU/mg protein in Wish cell line, similar to the bioactivity of original recombinant human IFN-alpha 2b. ELISA data showed that IFN-Pre S2 protein had antigenicities of both human IFN-alpha 2b and HBV Pre S2. In addition, fusion protein showed the feature of binding to polymeric human serum albumin (PHSA). CONCLUSIONS: The bifunctional fusion protein was efficiently expressed in E. coli. The work provided initial evidence for studying PHSA-receptor-targeting IFN-alpha 2b,which might have potential application for the treatment of HBV infection.