[Expression and identification of recombinant 22.6 kDa fusion protein of Schistosoma japonicum].

AIM: To obtain a large amount of purified 22.6 kDa antigen of Schistosoma japonicum (Sj22.6) in large quantity. METHODS: The sequence of the gene fragment encoding Sj22.6 was reformed by PCR and subcloned into plasmid vector pGEX-1 lambda T that coded for the 26 kDa GST antigen of Schistosoma japonicum (Sj26 GST). The recombinant plasmid was transformed into E. coli TG2 and then the positive recombinant clone was expressed by induction with IPTG. RESULTS: The recombinant Sj22.6/Sj26 GST fusion protein was expressed in 5.1% of total bacterial protein and was easy to be purified with glutathione sepharose 4B. Moreover, the purified recombinant Sj22.6 antigen could be cut off easily from the fusion protein with thrombin and had high immunogenicity. CONCLUSION: The purified recombinant Sj22.6 protein and Sj22.6/Sj26 GST fusion protein had the same immunological activity as the native Sj22.6 kDa protein.