日本血吸虫中国大陆株TPI基因的克隆及其表达产物特性

磷酸丙糖异构酶（ＴＰＩ）是血吸虫病疫苗重要的候选抗原基因之一。参考日本血吸虫已发表的ＴＰＩｃＤＮＡ序列，以日本血吸虫中国大陆株成虫ｍＲＮＡ为模板，用ＲＴ－ＰＣＲ法快速克隆出一大小约８００ｂｐ的ＤＮＡ片段。ＤＮＡ序列分析证实，所扩增到的ＤＮＡ片段即为日本血吸虫中国大陆株磷酸丙糖异构酶（ＳｊＴＰＩｃ）基因。将该基因重组到表达型质粒ｐＧＥＸ－４Ｔ中，表达的ＧＳＴ融合蛋白分子量约５４ｋＤ。用谷胱甘肽琼脂糖凝胶亲和层析柱纯化的重组蛋白不仅纯度好，而且得率高，纯化产量可达３０ｍｇ／Ｌ培养物。免疫试验结果表明该重组蛋白具有良好的抗原性，是一种较为理想的抗原分子。

Cloning of Schistosoma japonicum Chinese Strain TPI Gene and Characterization of Its Expression Product in Escherichia coli

Triose phosphate isomerase is an important candidate for schistosoma antigens. A 800 bp DNA fragment was amplified by RT PCR from adult Schistosoma japonicum mRNA. Sequence analysis revealed that this fragment contained S. japonicum (Chinese strain) triose phosphate isomerase gene. Then this gene was cloned into the expression vector pGEX 4T and subsequently expressed in Escherichia coli. The recombinant GST fusion protein was purified by glutathione agarose affinity chromatography. Its molecular weight was determined to be 54 kD. The yield of expression was around 30 mg/L E.coli culture. Western blotting showed that the recombinant protein had good antigenicity which could be helpful for the making of anti Schistosoma japonicum multi valent recombinant vaccine.