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志贺氏杆菌分泌蛋白Dnak的表达纯化与多克隆抗体的制备及应用OA北大核心CSTPCD

Expression and purification of Shigella secreted protein Dnak,preparation and application of polyclonal antibody

中文摘要英文摘要

目的 表达轮状病毒感染的乳鼠体内志贺氏杆菌分泌蛋白Dnak(Hsp70),并制备Dnak多克隆抗体.方法 以提取的志贺氏杆菌基因组为模板PCR扩增Dnak片段,与pET-24a(+)和PCDNA3.1分别连接构建原核表达质粒pET24a(+)-Dnak和真核表达质粒PCDNA3.1-Dnak;pET24a(+)-Dnak原核表达质粒转化至E.coli BL21(DE3)感受态细胞,IPTG诱导表达,经镍柱纯化Dnak蛋白.以纯化后的重组蛋白为免疫原免疫C57BL/6小鼠制备多克隆抗体,采用间接ELISA检测效价,Western Blot法检测灵敏度和特异性.利用制备的多克隆抗体在GST Pull-down实验中检测Dnak与轮状病毒非结构蛋白Nsp2的相互作用.真核表达质粒PCDNA3.1-Dnak转染至HEK293T细胞,以制备的DnaK多克隆抗体为一抗,Western blot法检测Dnak在细胞中的表达.利用MEGA11及Genedoc软件分析此志贺氏杆菌与志贺菌属其他细菌Dnak氨基酸序列同源性.结果 重组质粒pET24a(+)-Dnak与PCDNA3.1-Dnak经测序比对包含与此志贺氏杆菌(Shigella:PRJNA804371)序列一致的基因,证明质粒构建成功.诱导表达的重组Dnak蛋白主要以可溶性形式存在,相对分子质量约为75 kDa,浓度可达0.62 mg/mL;Dnak鼠多克隆抗体可与重组Dnak蛋白发生特异性反应,效价为1:32 000,至少可以在1:6 000稀释度下检测到Dnak蛋白.GST Pull-down实验可以检测到Dnak与轮状病毒非结构蛋白Nsp2发生相互作用.转染PCDN A3.1-Dnak重组质粒的HEK293T细胞可以表达Dnak蛋白.经 MEGA11和Genedoc软件比对PRJNA804371株与宋内志贺菌(Shigella sonnei)、痢疾志贺菌(Shigella dysenteriae)、鲍氏志贺菌(Shigella boydii)、福氏志贺菌(Shigella flexne-ri)Dnak氨基酸序列同源性较高.结论 成功表达志贺氏杆菌Dnak蛋白,具有良好反应性与免疫原性;制备的鼠多克隆抗体效价及灵敏度较高可满足后续实验需要.

The purpose of this study was to express the secreted Shigella protein Dnak(Hsp70)in rotavirus-infected suck-ling mice,and to prepare Dnak polyclonal antibodies.The extracted Shigella genome was used as a template to amplify the Dnak fragment by PCR.The prokaryotic expression plasmid pET24a(+)-Dnak and eukaryotic expression plasmid PCDNA3.1-Dnak were ligated with pET-24a(+)and PCDNA3.1,respectively,and the pET24a(+)-Dnak prokaryotic expression plasmid was transformed into E.coli BL21(DE3)competent cells.After IPTG-induced expression,Dnak protein was purified with a nickel column.Polyclonal antibodies were prepared from the purified recombinant protein for immunogenic C57BL/6 mice,and the antibody titer was detected by indirect ELISA.Antibody sensitivity and specificity were detected by western blotting.The interaction between Dnak and rotavirus non-structural protein Nsp2 was detected by GST pull-down assay.The eu-karyotic expression plasmid PCDNA3.1-Dnak was transfected into HEK293T cells,and the prepared Dnak polyclonal anti-bodies were used to detect the expression of Dnak in cells by western blotting.MEGA11 and Genedoc software were used to an-alyze the amino acid sequence homology between Shigella and other bacteria of the genus Shigella.The recombinant plasmids pET24a(+)-Dnak and PCDNA3.1-Dnak were sequenced and found to contain genes consistent with the sequence of Shigella:PRJNA804371,thus demonstrating successful plasmid construction.The induced expression of recombinant Dnak protein re-sulted primarily in soluble forms with a relative molecular weight of approximately 75 kDa;a concentration of 0.62 mg/ml;and good reactivity and immunogenicity.Dnak mouse polyclonal antibodies reacted specifically with recombinant Dnak protein at a titer of 1:32 000,and the limit of Dnak protein detection was a dilution of 1:6 000,thus indicating high titer and sensitivity to meet experimental needs.GST Pull-down assay can detect the interaction of Dnak with the rotavirus non-structural protein Nsp2.HEK293T cells transfected with PCDNA3.1-Dnak recombinant plasmid expressed Dnak protein.The PRJNA804371 strains were compared with MEGA11 and Genedoc software,and the amino acid sequence homology between the strains and Shigella sonnei,Shigella dysenteriae,Shigella boydii and Shigella flexneri was high.

贾雪娇;赵微;刘梦琦;刘洋;刘长城;李小凤;胡屹硕;李香雨;李润林;李永刚

锦州医科大学基础医学院病原生物学实验室,锦州 121001

基础医学

志贺氏杆菌Dnak蛋白表达与纯化多克隆抗体轮状病毒

ShigellaDnakprotein expression and purificationpolyclonal antibodiesrotavirus

《中国人兽共患病学报》 2024 (003)

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辽宁省科技厅自然科学基金面上项目(No.2021-MS-334);辽宁省教育厅面上项目基金(No.LJKMZ20221243) Supported by the Liaoning Provincial Department of Science and Technology Natural Science Foundation General Project(2021-MS-334)and the Liaoning Provincial Department of Education General Project Fund(No.LJKMZ20221243)

10.3969/j.issn.1002-2694.2024.00.039

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