Objective: To construct a recombinant plasmid containing surface antigen 2(SAG2) gene of Toxoplasma gondii and express it in Escherichia coli.
Methods: The truncated SAG2 gene was amplified from the genomic DNA of T. gondii RH strain and cloned into plasmid pGEX-4T. Then the recombinant pGEX-4T-SAG2 was induced by IPTG and expressed in E. richia col BL21. The expressed proteins were analyzed by SDS-PAGE and purified, and the immunogenicity of the product was analyzed by Western blotting.
Results: The amplified SAG2 gene was about 561 bp, which was accorded to the expectation. The recombinant plasmid was constructed successfully by digested with double restriction enzyme and confirmed with DNA sequencing. SDS-PAGE and Western blotting showed the molecular weight of SAG2 fusion protein was about 47 ku, and the protein could be identified by GST-tag antibody.
Conclusion: The truncated SAG2 gene of T. gondii has been successfully cloned and expressed in E. coli BL21 cells, and the recombinant protein has immunogenicity.