| Abstract: | This study was aimed to further investigate the structure and function of Brucella outer membrane protein 19 (OMP19),obtain the recombinant protein of OMP19 with reactivity,and establish the new method for diagnosing brucellosis based on indirect ELISA.The amino acid sequence of OMP19 protein was analyzed by bioinformatics software,Omp19 gene was amplified by PCR,and the recombinant expression vector pET-32a-Omp19 was constructed by seamless cloning method,it was transformed into E.coli BL21 (DE3) competent cells,induced and purified OMP19 protein.The immunogenicity of OMP19 protein was detected by Western blotting and ELISA,respectively,to establish an indirect ELISA method based on the protein.The results showed that there were 19 signal peptide sequences in the N terminal of OMP19 protein,and the secondary structure was random coil,and OMP19 protein contained dominant antigenic epitopes.The prokaryotic expression vector pET-32a-Omp19 was successfully constructed by PCR and seamless cloning method,the OMP19 fusion protein was successfully induced,expressed and purified,the size of protein was about 35 ku,which was consistent with the expect size.The reactivity of OMP19 was identified by Western blotting and ELISA,the results showed that the fusion protein had good reactivity,and the coating concentration was 10 μg/mL.The dilution ratio of the first antibody was 1：50 and the second antibody dilution ratio was 1：8 000,the P/N value reach the highest at 2.80.The results laid a foundation for the establishment of rapid diagnosis of brucellosis and the development of new vaccine. |
