Construction and identification of prokaryotic expression system for omp22ª²hpaA fusion gene from Helicobacter pylori

    HUANG Xueª²Yong, DUAN Guangª²Cai, FAN Qingª²Tang, XI Yuanª²Lin, HUANG Zhiª²Gang, SONG Chunª²Hua

    Department of Epidemiology, College of Public Health, Zhengzhou University, Henan Key Open Laboratory of Molecular Medicine, Zhengzhou 450052£¬China

    ¡¾Abstract¡¿ AIM£º To construct a prokaryotic high expression system which expresses fusion gene of outer membrane protein (omp22) gene and adhesion gene hpaA from Helicobacter pylori. METHODS£º The omp22ª²hpaA fusion gene with an adapter of 3 glycine residues was amplified by PCR, and cloned to the expression vector pMALª²c2X. The constructed recombinant plasmid was transformed in E.coli TB1 host bacterial strain and was induced by IPTG. The expression products were analyzed by SDSª²PAGE and Western Blot. RESULTS£º Sequencing results showed that the omp22ª²hpaA fusion gene consisted of 1326 bp and encoded the polypeptides of 440 amino acids and that the sequence (GGTGGAGGC) encoding 3 glycine residues was inserted into omp22ª²hpaA fusion gene as an adapter. The relative molecular weight of the expression product of omp22ª²hpaA fusion gene was about 53 ku. The amount of the recombinant gene expression products accounted for 20% of the total proteins of the host bacteria. CONCLUSION£º The omp22ª²hpaA fusion gene has been cloned and a prokaryotic high expression system for omp22ª²hpaA fusion gene been successfully constructed. ......