Separation And Purification And Antitumor Activity Reseach Of Peptide Pbn11-8 From Antarctic Marine Bacillus

Tumor is one of the most heavy diseases in the world. Antitumor drugs has a huge market demand, so antitumor lead compounds are playing an important role. Polar region not only is a potential and important bank of microorganisms, but also is a potential provenance for microbes, which create a new biologically active substance and lead compounds. In this study, microorganisms were isolated from surface water samples at different sites of the Antarctic. The fermented products of these microbes were carried out antitumor activity selection by the MTT activity tracking method according to a model of BEL-7402 human hepatoma cells. Results showed that the inhibition rate of fermented products of the strain N11-8 was 68.1%. Through the analysis of physiological and biochemical characteristics and the 16S rRNA analysis, the strain N11-8 was identified as Bacillus. By the methods of MTT activity tracking and SDS Polyacrylamide gel electrophoresis, and combined with ultrafiltration, ammonium sulfite precipation, anion exchange liquid chromatography and High Performance Liquid Chromatography (HPLC), the polypeptide, PBN11-8, which possesses antitumor activity, was separated and purified from fermentation broth of Bacillus sp. N11-8. The molecule weight of PBN11-8 was measured as 19kDa by Electronic Spray Ion (ESI) mass spectrometry. The PBN11-8 showed modest cytotoxicity towards a panel of cultured cells, which gave IC50 of 1.56,1.80,1.81, and 2.31μg/mL against BEL-7402,786-0, NIH:OVCAR-3 and NCI-H460, respectively. However, it displayed lower cytotoxicity to L-02 human normal cells. By phase contrast microscope, BEL-7402 cells were become spherical, shrinkage, fewer intercellular links, most cell shedding, the number of cells reduction by PBN11-8. And it will be enhanced as time increasing. The scratch test and Transwell experiment proved that PBN11-8can inhibit the migration and invasion of BEL-7402 cells. Overall, all the microbes in our work provided a new Antarctic microorganisms resource for activity componds of drug candidates; PBN11-8 is expected to become a novel anti-cancer lead compound, and has good prospects for application.