中国寄生虫学与寄生虫病杂志 ›› 2010, Vol. 28 ›› Issue (4): 5-265.

• 论著 • 上一篇    下一篇

细粒棘球绦虫FABP与Eg95融合基因的表达与抗原性鉴定

王玲1, 胡慧霞2, 曾素祥3, 武伟华3, 甘文佳3, 胡黎平1, 胡旭初3 *   

  1. 1 中山大学基础医学实验教学中心,广州 510080;2 广州金域医学检验中心有限公司,广州 510330;3 中山大学中山医学院寄生虫学教研室,广州 510080
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2010-08-30 发布日期:2010-08-30

Expression and Characterization of the FABP and Eg95Fusion Gene from Echinococcus granulosus

WANG Ling1, HU Hui-xia2, ZENG Su-xiang3, WU Wei-hua3,
GAN Wen-jia3, HU Li-ping1, HU Xu-chu3 *
  

  1. 1 Experimental Center for Basic Medical Teaching,Sun Yatsen University,Guangzhou 510080,China;2 Guangzhou Kingmed Diagnostics Center Co. Ltd.,Guangzhou 510330,China;3 Department of Parasitology,Zhongshan Medical School,Sun Yatsen University,Guangzhou 510080,China
  • Received:1900-01-01 Revised:1900-01-01 Online:2010-08-30 Published:2010-08-30

摘要: 目的 构建细粒棘球绦虫脂肪酸结合蛋白(FABP)和Eg95两个保护性抗原基因的融合基因,并研究其重组蛋白的免疫学特性。 方法 以细粒棘球绦虫青海绵羊株保护基因FABP和Eg95的cDNA为模板,通过编码4个甘氨酸残基的连接序列,用非对称聚合酶链反应扩增融合基因FABP·Eg95,克隆至表达载体pET28a(+)中, 在大肠埃希菌BL21(DB3)中用异丙基-β-D-硫代半乳糖苷(IPTG)诱导表达,表达产物以十二烷基硫酸钠?鄄聚丙烯酰胺凝胶电泳(SDS-PAGE)进行鉴定。通过Ni?鄄IDA亲和层析获得高纯度目的蛋白,利用蛋白质印迹(Western blotting)分析重组蛋白的免疫反应性。 结果 获得的融合基因FABP·Eg95长约795 bp,双酶切和测序鉴定结果均显示pET-28a(+)-FABP-Eg95重组质粒构建成功。SDS-PAGE结果表明,重组质粒pET-28a(+)-FABP-Eg95在大肠埃希菌BL21(DB3)中获得高效表达,表达相对分子质量(Mr)约为31 000的重组蛋白,主要以包涵体形式存在,经亲和层析获得目的蛋白。Western blotting分析结果显示,重组蛋白与细粒棘球蚴病患者血清有良好的免疫反应性,而不与健康人血清和血吸虫病患者血清反应。 结论 FABP·Eg95融合基因构建成功,纯化的重组蛋白具有一定的抗原性。

关键词: 细粒棘球绦虫, Eg95, 脂肪酸结合蛋白, 蛋白质印迹

Abstract: Objective To construct and express a fusion gene of fatty acid binding protein (FABP) with Eg95 which are protective antigen genes of Echinococcus granulosus, and investigate the immunological characteristics of the recombinant protein. Method Using cDNA fragments encoding FABP and Eg95 genes from E. granulosus Qinghai sheep strain as templates, a fusion gene FABP·Eg95 was amplified by asymmetric polymerase chain reaction through a linking sequence encoding four glycine residues. The PCR products of fusion gene were subcloned into the pET28a (+) vector. The recombinant plasmid was transformed into Escherichia coli BL21(DE3) cells and induced with IPTG. The recombinant protein was detected by SDS-PAGE and purified by Ni-IDA affinity chromatography, and its immunogenicity was analyzed by Western blotting. Results The fusion gene length was about 795 bp. Double enzyme digestion analysis and DNA sequencing confirmed that the fusioin gene was cloned into pET-28a (+). The recombinant protein (Mr 31 000) was expressed in inclusion body in E. coli expression system, and was purified by Ni-IDA affinity chromatography. Western blotting analysis testified that the recombinant protein could be recognized by sera of cystic echinococcosis patients, but not by sera of healthy persons and schistosomiasis patients. Conclusion The FABP·Eg95 fusion gene has been constructed, and the purified recombinant protein has been confirmed with immunogenicity.

Key words: Echinococcus granulosus, Eg95, Fatty acid bindding protein, Western blotting