The E.coli DH5α cells harboring the pGXmTSST gene was induced by adding isopropyl-β-D-thiogalactoside（IPTG）,the bacteria were collected by centrifugation and were disrupted by sonication.The notoxic and mutant GST-mTSST-1 fusion protein of Staphylococcus aureus were isolated and purified by glutathione S-transferase agarose resin affinity chromatography column.The expression product and purity of GST-mTSST-1 fution protein were analyzed by sodium dodecylsulfate polyacrylanide gels（SDS-PAGE） electrophoresis,and the immune activity were tested by agar-gel double immunodiffussion essay.The results showed that the high purity and soluble GST-mTSST-1 fution protein were obtained by GS4B affinity chromatography and SDS-PAGE,its relative molecular mass was 47000.The polyclonal rabbit antiserum reacted readily with purified GST-mTSST-1 fution protein and rTSST-1,and the precipitation lines between GST-mTSST-1 and rTSST-1 were united each other.These results indicated that GST-mTSST-1 retained the same antibody-binding epitopes as wild-type rTSST-1and had well immunogenicity.%将DH5α/pGXmTSST基因工程菌用IPTG诱导表达,经超声波破碎、离心、收集上清再用谷胱甘肽琼脂糖凝胶柱（GS4B）亲和层析纯化金黄色葡萄球菌无毒诱变GST-mTSST-1融合蛋白.以SDS-PAGE分析该融合蛋白的表达量和纯度,经双向免疫琼脂扩散试验鉴定GST-mTSST-1融合蛋白的免疫活性.结果表明,GST-mTSST-1融合蛋白在重组菌中可溶性表达,通过GS4B胶亲和层析纯化,SDS-PAGE电泳分析得到纯度较高的目的蛋白,其相对分子质量约为47 000,与理论值一致.兔抗GST-mTSST-1抗血清可特异识别天然rTSST-1蛋白中与GST-mTSST-1融合蛋白相对应的抗原组份,证实GST-mTSST-1融合蛋白具有与野生型rTSST-1相同的表面抗原决定簇,具有较好的免疫原性.
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