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.