Abstract: The study was aimed at cloning, expressing the gene of outer membrance protein 2b (Omp2b) and analyzing the bioinformatics of Omp2b, according to the nucleotide sequence of Omp2b gene of Brucella melitensis M5-90, a pair of primers was designed, and Omp2b gene fragment was amplified from Brucella genome by PCR.The fragment was identified and cloned into prokaryotic expression vector pMD20-T. After sequencing, Omp2b fragment was ligated into pET28a to construct the recombinant expression plasmid pET28a-Omp2b, and then transformed into the E.coli BL21 (DE3) strains. IPTG was used to induce expression of Omp2b protein,and the protein was detected by SDS-PAGE and Western blotting. DNAMAN and BioEdit softwares were used to analyze the sequence of amino acids encoded by Omp2b gene. The results showed that Omp2b gene was cloned successfully; the ORF was 1041 bp, which encoded 347 amino acids; the expression vector pET28a-Omp2b was constructed; the molecular weight of the expression protein was about 38 ku; Omp2b protein secondary structure of alpha helix, extended strand, β turn and random coil were accounted for 20.17%, 26.22%, 5.76% and 47.84%, respectively.

Key words: Brucella; Omp2b; cloning; prokaryotic expression; bioinformatics analysis