Zheng Da-li, Huang Qing-ling, Zhang Tao, Lin Jian-yin
Department of Biochemistry and Molecular Biology, Fujian Medical University, Fuzhou 350004.
Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi. 2003;21(4):230-3.
To obtain protein of the major surface antigen P30 of Toxoplasma gondii by molecular cloning.
The gene of P30 (containing the whole P30 gene sequence, without the gene encoding signal peptide) was obtained by polymerase chain reaction (PCR) using the primer designed according to the DNA sequence of P30. The recombinant plasmid was constructed using EcoR I, Xho I and was then transformed into E. coli Top10. The positive clones were identified by restriction enzymes and DNA sequence analysis. The fusion protein was induced by IPTG and purified by affinity chromatography using ProBond Resin (a kind of nickel-charged sepharose resin) and was identified by SDS-PAGE and Western blotting.
The products of PCR, cleavage and link reaction were same as expected and the sequence of inserted fragment in the recombinant plasmid was same as reported except one synonymy mutation. A 58 kDa fusion protein was induced by IPTG and was purified by chromatography.
Fusion protein containing Toxoplasma gondii P30 was achieved and was provided as experiment material for further research.
通过分子克隆获得弓形虫主要表面抗原P30的蛋白。
根据P30的DNA序列设计引物,通过聚合酶链反应(PCR)获得P30基因(包含完整的P30基因序列,不含编码信号肽的基因)。使用EcoR I、Xho I构建重组质粒,然后转化至大肠杆菌Top10。通过限制性内切酶和DNA序列分析鉴定阳性克隆。用异丙基-β-D-硫代半乳糖苷(IPTG)诱导融合蛋白表达,并用ProBond树脂(一种镍负载的琼脂糖树脂)通过亲和层析法进行纯化,通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)和蛋白质免疫印迹法(Western blotting)进行鉴定。
PCR、酶切和连接反应产物与预期一致,重组质粒中插入片段的序列与报道的一致,但有一个同义突变。IPTG诱导出一个58 kDa的融合蛋白,并通过层析法进行了纯化。
获得了含弓形虫P30的融合蛋白,为进一步研究提供了实验材料。