A preliminary Study: Expression of Rhoptry Protein 1 (ROP1) Toxoplasma gondii in Prokaryote System

Background: Toxoplasma gondii is an obligatory intracellular protozoan parasite, which infects human beings. Since the current antigens used for diagnosis or vaccination are contaminated with non parasitic material in which the parasite is grown, it is tried to produce recombinant antigens to design vaccines against toxoplasmosis, or make diagnostic kits. Choosing the type of antigen to produce recombinant vaccine or diagnostic kits is considerably important. The rhoptry protein 1 is one of the excretory-secretary antigens of Toxoplasma which seems to be an appropriate candidate in production of recombinant vaccines and diagnostic kits. Objectives: The current study aimed to produce rhoptry protein 1 from Iranian strains of Toxoplasma for further investigations. Materials and Methods: Genomic DNA was isolated from tachyzoite of parasite by phenol chloroform method and gene fragment was amplified by polymerase chain reaction. The polymerase chain reaction products were ligated into restriction enzymes sites of pTZ57R/T cloning vector. The product was sub-cloned into a prokaryotic expression plasmid (pET32a). The recombinant expression vector containing rhoptry protein 1 sequence was transformed into Escherichia coli BL21 pLysS and was induced by isopropyl β-D-1-thiogalactopyranoside. The sodium dodecyl sulfate polyacrylamide gel electrophoresis and western blotting methods were used to confirm the production of protein. Results: The result showed that the desired molecular weight protein is produced. Recombinant protein was confirmed by western blot using Ni-NTA- conjugate. Conclusions: The result of this study showed that recombinant ROP1 Toxoplasma was produced successfully. In the present study, unlike other studies, the goal was to express full length of ROP1. Also this protein was produced alone not fused with other proteins.