中国寄生虫学与寄生虫病杂志

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刚地弓形虫自噬相关蛋白3基因的克隆表达与多抗制备

华倩倩1,李相志2,万玉静2,陈弟3,赵徐寒晖3,蒋凯3,胡昕4,潘长旺2,谭峰2 *   

  1. 1 东阳市人民医院检验科,金华 322100;2 温州医科大学基础医学院,温州 325035;3 温州医科大学第一临床医学院,温州325035;4 温州医科大学生命科学学院、检验医学院,温州 325035
  • 出版日期:2014-12-30 发布日期:2015-02-12

Cloning and Expression of Toxoplasma gondii Autophagy-related Protein 3 Gene and Preparation of Its Polyclonal Antibody

HUA Qian-qian1,LI Xiang-zhi2,WAN Yu-jing2,CHEN Di3,ZHAO Xu-han-hui3,JIANG Kai3,HU Xin4,PAN Chang-wang2,TAN Feng2 *   

  1. 1 Clinical Laboratory,Dongyang People’s Hospital,Jinhua 322100,China;2 School of Basic Medical Sciences,Wenzhou Medical University,Wenzhou 325035,China;3 The First Clinical Medical College,Wenzhou Medical University,Wenzhou 325035,China;4 School of Medical Laboratory Science and School of Life Science,Wenzhou Medical University,Wenzhou 325035,China
  • Online:2014-12-30 Published:2015-02-12

摘要:

目的  克隆、表达刚地弓形虫(Toxoplasma gondii)自噬相关蛋白3(TgAtg3)基因,并制备能特异性识别该蛋白的多克隆抗体。  方法  以弓形虫RH株cDNA为模板,构建pET28a-TgAtg3重组质粒,转化入大肠埃希菌(E. coli)Rosetta感受态细胞,经自诱导培养基诱导表达,用镍柱亲和层析法纯化诱导表达产物,以小鼠抗His标签单克隆抗体作为一抗,蛋白质印迹(Western blotting)进行鉴定。以纯化的TgAtg3蛋白作为抗原皮下多点注射免疫日本大耳白兔,125 μg/(只·次),免疫4次后心脏取血,制备血清,获得特异性抗TgAtg3多克隆抗体。对制备的多克隆抗体进行Western blotting与间接免疫荧光法(IFA)鉴定。  结果  双酶切、PCR扩增及测序结果证实目的片段序列正确,原核表达质粒pET28a-TgAtg3构建成功。SDS-PAGE和Western blotting结果表明,重组E. coli中可见相对分子质量(Mr)约44 000的可溶性TgAtg3蛋白的高效表达。抗体检测Western blotting结果显示,制备的多克隆抗体能特异性识别弓形虫RH株的TgAtg3蛋白。IFA结果显示,该多克隆抗体可与虫体胞浆内TgAtg3结合。  结论  获得重组可溶性TgAtg3蛋白,制备的多克隆抗体能特异性识别弓形虫RH株的天然Atg3蛋白。

关键词: 刚地弓形虫, 自噬相关蛋白3, 克隆, 表达, 多克隆抗体

Abstract:

Objective  To clone and express autophagy-related protein 3 (TgAtg3) gene of Toxoplasma gondii, and obtain the specific polyclonal antibody against TgAtg3.  Methods  TgAtg3 cDNA was inserted into prokaryotic expression vector pET28a. After identification, the constructed plasmid pET28a-TgAtg3 was transformed into E. coli Rosetta cells, and induced by special induction medium for expression of the protein. The recombinant protein was purified via Ni-NTA affinity chromatography. Western blotting assay was performed with anti-His tag mouse monoclonal antibody as the primary antibody. Rabbits were immunized with 125 μg purified TgAtg recombinant protein. Each rabbit received 4 immunizations at 2-week intervals with the same dose of antigen. The specific anti-TgAtg3 polyclonal antibody was obtained, and analyzed by Western blotting and indirect immunofluorescence assay (IFA).  Results  pET28a-TgAtg3 plasmid was identified by restriction enzyme digestion, PCR amplification and sequencing. SDS-PAGE and Western blotting analysis showed that the recombinant TgAtg3 protein (about Mr 44 000) was expressed in E. coli Rosetta cells. TgAtg3 protein from tachyzoite lysates was recognized by the specific anti-TgAtg3 polyclonal antibody. IFA assay determined that the specific polyclonal antibody bound to TgAtg3 protein from the cytoplasm of tachyzoites.  Conclusion  The obtained soluble polyclonal antibody against TgAtg3 can specifically react to the endogenous TgAtg3 protein.

Key words: Toxoplasma gondii, Autophagy-related protein 3, Clone, Expression, Polyclonal antibody