[Cloning, expression and identification of membrane protein Tetraspanin 2-A of Schistosoma japonicum].

OBJECTIVE: To clone and express a membrane protein (Tetraspanin 2) gene of Schistosoma japonicum (SjTsp2). METHODS: A pair of primers was designed to amplify the SjTsp2 gene which was subcloned into prokaryotic plasmid pET28a(+). The recombinant plasmid was transformed into E. coli BL21(D3) and followed by expression of the protein induced by IPTG. The protein was purified by affinity chromatography and used to immunize BALB/c mice. Dilution of antibody against SjTsp2 was determined by ELISA. The protein was also identified by Western blotting. RESULTS: Big loop of SjTsp2-A, 228 bp, was amplified in vitro by PCR. Its deduced amino sequence shared 52% similarity with SmTsp2. The soluble recombinant SjTsp2-A was expressed in the experiment and high dilution antibody against the recombinant (1:32,000 in maximum) was produced in immunized mice. SjTsp2-A reacted positively with sera of acute and chronic schistosomiasis patients but not with sera from healthy persons by Western blotting. CONCLUSION: SjTsp2 has been expressed and shows certain antigenicity.