Researches on cloning and expression of the gene encoding Schistosoma japonicum tetraspanins extracellular loop 2 and its immunogenicity

Objective To clone and express the gene(Sj-tsp-2) encoding extracellular loop 2(EC-2) of tetraspanins(TSPs) of Schistosoma japonicum(Chinese strain),and then to study the antigenicity and immunogenicity of this protein.Methods Synthesized Sj-tsp-2 gene was cloned into prokaryotic expression vector pET32a to generate pET32a-Sj-tsp-2 recombinant plasmid,and transformed into competent E.coli BL21(DE3).After inducing with IPTG,the expressed fusion protein was purified under nondenaturing conditions.Results The recombinant was confirmed by sequence analysis.The size of fusion protein and interest peptide was accords with the theoretical value by SDS-PAGE analysis.Additionally,the results of Western Blotting and ELISA demonstrated that the expressed protein had good immunogenicity.More importantly,we confirmed that TSP-2 is mainly located on the surface of S.japonicum.Conclusion The successful expression and purification of recombinant protein Trx-Sj-TSP-2 will be very helpful for the further study of its protection role in animals.