Cloning and expression of Toxoplasma gondii tachyzoite P22 protein

Delay in diagnosis of Toxoplasma gondii infection in pregnant women who have been infected during the first trimester of gestation can lead to death of her fetus. Serological tests based on recombinant proteins are the main diagnosis methods for the detection of anti Toxoplasma antibody in serum samples. The aim of this study was to clone and express a gene encoding a P22 protein of T. gondii tachyzoite as using antigen for ELISA serology method. DNA was extracted from T. gondii (RH-strain) tachyzoites and PCR reaction was done using corresponding primers. The PCR product was purified, ligated to PTZ57R plasmid via T/A cloning method and subcloned into Sad and BamHI digested pET32a expression vector. Recombinant plasmid was transformed in E. coli (BI21 DE3) and induced by 1 mM IPTG and analyzed by 12% SDS-PAGE. Expressd protein was purified by affinity chromatography and confirmed by western blot analysis. We successfully cloned and expressed T. gondii P22 protein.