Soluble expression and characterization of the immunoreactive multiepitope antigen of Toxoplasma gondii in E.coli

Abstract

Abstract: Objective To obtain soluble expression product of immunoreactive recombinant multiepitope antigen of Toxoplasma gondii from E.coli.Methods The gene encoding the multiple epitopes (MEG) of Toxoplasma gondii was amplified by PCR from the original plasmid containing MEG gene and cloned into the prokaryotic soluble expression vector pET32a. After identification by enzyme digestion and sequencing, the positive recombinant plasmid pET32a-MEG was transformed into BL21(DE3), which was induced with IPTG for expression of the target antigen. The relative molecular mass, solubility and antigenicity of the expression products were analyzed by SDS-PAGE and Western blotting.Results The recombinant expression plasmid pET32a-MEG was successfully constructed and the highly efficient expression of the antigen was achieved after IPTG induction of E.coli. Improvement of the induction condition increased the expression product which accounted for about 28% of the total bacterial protein. The target protein, with good solubility and a relative molecular mass of about 31 000, was purified by immobilized metal affinity chromatography (Ni-NTA resin) and could be well recognized by mouse and rabbit antisera derived by infection of the animals with Toxoplasma gondii B36 and RH, respectively.Conclusion The recombinant multiepitope antigen has good antigenicity and potential value in diagnosis and vaccine development of toxoplasmosis.

CLC Number:

Q785
R382.5

YANG Pei-liang¹, CHEN Xiao-guang², WANG Yuan-zhan¹, LI Hua², ZHOU Xiao-hong², WU Kun², YAN Hui². Soluble expression and characterization of the immunoreactive multiepitope antigen of Toxoplasma gondii in E.coli[J]. Journal of Southern Medical University, 2005, 25(05): 528-530,544.

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