Abstract:

 Objective  To clone and express the gene encoding Schistosoma japonicum myophilin-
like protein (SjcMLP) and to study the antigenicity of the recombinant protein. Methods  The
SjcMLP gene was amplified by PCR. The PCR product was cloned into T vector, and then sub-
cloned into expression vector pQE30. The recombinant plasmid of pQE30-SjcMLP was transformed
into E. coli M15, and induced with IPTG for expression.  The bacteriallysis was conducted by ultra-
sonication and the supernatant was analysed by SDS-PAGE. The recombinant protein (reSjcMLP)
was purified with the Ni-NTA resin, and analysed with SDS-PAGE and Western blot. The titers of
sera from C57BL/6 mice immunized subcutaneously with reSjcMLP were detected by ELISA. Re-
suIts  The results of SDS-PAGE and Western blot showed that the molecular weight of expressed
fusion protein was around 24. 8 kDa and was recognized by the sera from the mice infected with
Schistosoma japonicum. The purified protein of reSjcMLP was coated for ELISA test and the IgG
titers in the sera from the mice immunized with reSjcMLP were as high as l : 12 800 reacted with.
However, no significant difference was found in worm reduction rates between the immunized mice
and control mice. Conclusions  The fused recombinant protein of reSjcMLP is successfully ex-

摘要：

目的克隆和表达日本血吸虫嗜肌素样蛋白(SjcMLP)编码基因，并研究其重组抗原的免疫原性。方法PCR扩增SjcMLP编码基因，并亚克隆人表达载体pQE30。将重组表达质粒pQE 30-SjcMLP转入宿主菌E. coli M15，异丙基-βD-硫代半乳糖苷(IPTG)诱导表达，用金属Ni螯合物亲和层析柱(Ni-NTA)纯化SjcMLP重组蛋白(reSjcMLP)。纯化的reSjcMLP采用十二烷基磺酸钠一聚丙烯酰胺凝胶电泳(SDS-PAGE)和免疫印迹试验(Western blot)作进一步分析。采用酶联免疫吸附试验(ELISA)测定用reSjcMLP免疫C57BL/6小鼠血清中的抗体水平。结果  SDS-PAGE分析表明获得的重组抗原的大小约24.8 kDa，与预的融合蛋白大小相符。Western blot昱示该重组抗原能被日本血吸虫尾蚴感染兔血清识别。用该重组抗原包被进行ELISA检测，免疫血清滴度高达1：12 800。但动物免疫试验结果减虫效果不明显。结论SjcMLP编码基因以可溶性融合蛋白的形 式得到表达，动物免疫试验未诱导出明显的保护力

关键词:  日本血吸虫；嗜肌素样蛋白；克隆；表达；免疫