Expression, purification and identification of recombinant Omp~2 of Chlamydia trachomatis / 中华检验医学杂志

ABSTRACT

Objective To express outer membrane protein 2(Omp2) of Chlamydia trachomatis, purify expressed products and study its immunity.Methods The target gene encoding Omp2 167—434 amino acid residues was amplified by PCR from C. trachomatis template DNA. The targeted DNA fragment was cloned into expression vector pET28b(+) and introduced into competent E. coli BL21(DE3) cell. Recombinant Omp2aa_ 167 ～aa_ 434 was expressed after induction by IPTG and analyzed by SDS-PAGE and Western blot, purified with Ni-NTA-His affinity chromatography. The rOmp2aa_ 167 ～aa_ 434 was used to immune rabbits for immunogenicity assessment.Results Restriction enzymes cleavage analysis and DNA sequencing confirmed that the plasmid pET28b(+)/Omp2aa_ 167 ～aa_ 434 was correctly constructed. The 35.0?103 molecular weight pure protein, which specifically reacted with serum from C. trachomatis infected patient by Western blot, was obtained by optimizing the conditions for both expression and purification. The titer of serum antibodies was above 1∶1 280 as detected by ELISA.Conclusion The expressed product showed good immunity.