Expression and identification of outer membrane protein 2b(OMP2b) of Brucella abortus strain A19

According to the gene sequence of Brucella abortus available in GenBank,a pair of primers was designed and used for PCR amplification of the complete OMP2b gene from B.abortus strain A19.The PCR product was cloned into pMD18-T vector and subsequently sequenced.In result,the OMP2b gene was 1 128 bp in length,encoding 376 amino acids.The gene was then cloned into the expression vector pCold TF to construct recombinant plasmid pCold TF-OMP2b.The fused protein His-OMP2b was expressed in Esc-herichia coli BL21(DE3) by IPTG induction and identified to be 93 ku in size by SDS-PAGE,and reacted with rabbit antiserum against B.abortus by Western-blot,indicating that the fusion protein His-OMP2b had immunogenicity.