中国寄生虫学与寄生虫病杂志 ›› 2004, Vol. 22 ›› Issue (2): 8-97.

• 论著 • 上一篇    下一篇

恶性疟原虫谷氨酸脱氢酶在大肠埃希菌中的可溶性表达、纯化和鉴定

李妍,宁云山,董文其,李明   

  1. 第一军医大学热带医学研究所,广州510515
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2004-04-30 发布日期:2004-04-30

Soluble Expression of Plasmodium falciparum Glutamate Dehydrogenase in Escherichia coli, and its Purification and Identification

LI Yan;NING Yun-shan;DONG Wen-qi;LI Ming   

  1. Institute of Tropical Medicine,First Military Medical University,Guangzhou 510515,China
  • Received:1900-01-01 Revised:1900-01-01 Online:2004-04-30 Published:2004-04-30

摘要: 目的 在大肠埃希菌 (E .coli)中尝试非融合蛋白技术可溶性表达恶性疟原虫谷氨酸脱氢酶 (GDH) ,以获得具有相对完整空间表位的重组非融合GDH。 方法 将恶性疟原虫GDH基因克隆到pET-23 (a)表达载体中 ,转化E .coli BL21菌株 ,异丙基-β-D-硫代半乳糖苷诱导表达 ,菌体反复冻融后 ,通过十二烷基硫酸钠 聚丙烯酰胺凝胶电泳 (SDS-PAGE)分析表达产物的存在形式 ,可溶性表达产物经Source-Q及Source-S层析纯化并用SDS PAGE分析纯度。通过蛋白质印迹试验鉴定表达和纯化产物的免疫学活性。 结果 可溶性重组GDH分子占宿主蛋白 15 %左右 ,相对分子质量为 5 2 0 0 0。经过阴离子和阳离子交换层析纯化后 ,GDH纯度达 90 %以上。该蛋白质具有良好的抗原性。 结论 通过E .coli表达系统和柱层析分离技术可获得高纯度、具有相对完整空间表位的重组GDH分子。

关键词: 恶性疟原虫, 谷氨酸脱氢酶, 基因表达, 蛋白质印迹试验

Abstract:

Objective To make soluble expression of Plasmodium falciparum (FCC1/HN) glutamate dehydrogenase(GDH) in Escherichia coli, purification and immunocompetence identification of the recombinant non-fusion GDH. Methods The GDH gene was cloned into prokaryotic expression vector pET23(a) to form recombinant expression vector pET23(a)/GDH. pET23(a)/GDH was transformed into E.coli BL21(DE3). Induced by IPTG(isopropyl-beta D-thiogalactoside), GDH was highly expressed in the supernatant after sonication. The soluble recombinant GDH was purified by Source-Q and Source-S chromatography. Enzyme-linked immunosorbent assay and Western blotting were carried out to identify the immunocompetence of the purified product. Results SDS-PAGE analysis showed that the soluble GDH protein accounted for approximately 15% of the total bacterial protein. By two-step ion-exchange chromatography, the purity of GDH reached more than 90% and the GDH possessed high antigenicity. Conclusion The soluble expression of GDH results in an integral three-dimensional structure epitope with high biological activity.

Key words: Plasmodium falciparum, glutamate dehydrogenase, gene expression, Western blotting