The Design, Synthesis, Cloning And Expression In Pichia.pastoris Of A New Antibacterial Peptide-Cecropin B Gene

Anti-bacterial peptide (abbrevitated form-ABP) is a kind of small size molecule peptides that are encoded by a special gene, still are important molecular protective screen of that the host defend pathogenic bacteria invaders, these peptides are produced in large quantities at sites of infection and inflammation for organism,antibacterial peptides not only kill Gram-positive and Gram-negative bacteria in broad spectrum and high efficiency,but also kill some virus,fungi and protozoan, furthermore these peptides have selective capability to kill some cancer cells,but they are nontoxic for normal mammalian and insect cells.In the paper, by analyzing the primary structure and the secondary structure of antibacterial peptides, according to the codons preferred by plants we design a new antibacterial peptide on the base of Cecropin B gene sequence, the new Cecropin B gene artificially synthesized through gene splicing by overlap extension (gene SOEing) method,and then insert the new Cecropin B gene into a highly effective expression vector-pPIC9K in Pichia.pastoris,the new antibacterial peptide are expressed and secreted extracellularly and get the ABP.testing the antibacterial activity of the new antibacterial peptide-Cecropin B.the final object is transforming the new active anti-bacterial peptide into crops and getting the transgenic crops that resist both E.carotovora and Pseudomonas solanacearum pv tabaci that are epidemic disease for crops in our country.