Molecular Screening of Azurin-Like Anticancer Bacteriocins from Human Gut Microflora Using Bioinformatics

摘要

There has been renewed interest in the development of new cancer therapeutic drugs based on the use of live bacteria and their purified products. Bacteriocins are antimicrobial peptides produced by bacteria to inhibit the growth of closely related bacterial strains, and sometimes against a wide spectrum of species. As one of few known anticancer bacteriocins, Azurin can specifically penetrate human cancer cells and exerts cytostatic and apoptotic effects. We hypothesized that pathogenic and commensal bacteria with long term residence in human body can produce Azurin-like bacteriocins as a weapon against the invasion of cancers. Putative bacteriocins were screened from complete genomes of 66 dominant bacteria species in human gut microbiota using Bagel database and subsequently characterized by subjecting them as functional annotation algorithms using Prot fun2.2, Kihara Bioinformatics and BaCelLo with Azurin as control. The prediction of functional characterization including cell envelope activity, enzymatic activity, immune response, the number of protein phosphorylation sites and localization within the cell revealed that 14 bacteriocins possessed functional properties very similar to those of Azurin. This is first study on genomic-scale screening of anticancer bacteriocins from all dominant bacteria species in human gut microbiota.