Expression, purification and characterization of P35 recombinant antigen of Toxoplasma gondii.

Objective Expression,purification and characterization of P35 recombinant antigen of Toxoplasma gondii in E.coli JM109. Methods The gene encoding P35 surface antigen was amplified by RT-PCR,from a Toxoplasma gondii cDNA libray,and cloned into plasmid pGEX-2TK to construct a recombinant plasmid P35/pGEX,Then transformed it into E.coli JM109.The positive recombinant clone was induced by IPTG to express target fusion protein GST-p35 which was easy to be purified with GSTrap TM column and Trombin Protease.The purified product was analyzed by SDS-PAGE and Western-blot. Results The fusion GST-P35 protein was about 54 kDa and P35 recombinant antigen protein about 28 kDa respectively.The purified GST-P35 protein can be recognized by anti-GST antibody and the serums of infected rabbits by Western-blot. Conclusion The recombinant plasmid P35/pGEX was constructed and expressed in E.coli JM109,and the purified fusion protein GST-P35a and P35 recombinant protein have good antigenicity.