【摘要】 以重组质粒pSj26为模板，PCR扩增出编码26kDa谷胱甘肽S-转移酶（Sj26GST）的cDNA，双酶切后克隆到pBV220DNA，构建pBV220-Sj26温控表达载体，CaCl2法转化大肠杆菌DH5α，氨苄青霉素筛选转化子，酶切图谱分析及PCR鉴定阳性克隆。阳性克隆菌在30℃培养，42℃温控表达Sj26。测定表达产物GST活性，并用rSj26抗原免疫的鼠血清及日本血吸虫感染鼠血清进行Dot－ELISA和Westernblot检测其抗原性。实验结果表明PBV220－Sj26温控表达产物具有GST酶活性。SDS－PAGE经考马斯亮蓝染色可见染色较深的26kDa条带，该条带占菌体总蛋白的33．83％。抗rSj26的免疫鼠血清及日本血吸虫感染鼠血清均可识别26kDa条带。实验结果表明日本血吸虫26kDa条带能在大肠杆菌温控高效表达。更多还原

【Abstract】 The cDNA encoding 26 kDa GST of Chinese strain S. japonicum was ligated with effi cient temperature-dependent pBV220 vector to construct pBV220-Sj26 expression vector,and then introduced into E. coli DH,. by CaCl, method. Trans formants were selected byampicillin and recombinant clones were identified by restriction mapping and PCR. The tem perature-dependent expression-cultured at 3OC and expressed at 42C, was per formed bypositive clone carrying pBV220-Sj26 DNA. The GST expression ability was investigated byenzymic activity assay and SDS-PAGE, and antigenicity by Dot-ELISA and Western blot.The results showed that the cultures posseseed GST activity. A higher level of GST activitywas expressed at six hours after the temperature increased to 42℃. The more heavily stained26 kDa protein band, which posseseed 33. 83% of the total bacteria protein, was displayedby SDS-PAGE and recognized by antibodies in sera of mice immunized with rSj26 and infected with S. japonicum. It suggested that 26 kDa GST of S. japonicum could be expressed bythe temperature-dependent method with high efficiency更多还原