Defense proteins with antiproliferative and antimicrobial activities from fungi and bacteria

Abstract

Defensins are a group of proteins characterized by a conservedcysteine-stabilized alpha-helix and beta-sheet structural motif. They are widely distributed among vertebrates and invertebrates. In addition to the presence of defensins in mammals and submammalian vertebrates enumerated in Chap. 23, fungi and bacteria also produce a variety of defensins with antiproliferative activity toward tumor cells and anticancer activity in tumor bearing mice. The fungal proteins include ribonucleases, antifungal proteins, antibacterial proteins, ubiquitin-like peptides, ribosome inactivating proteins, hemolysins, hemagglutinins/lectins, laccases, and proteases. The bacterial proteins comprise ribonucleases and antifungal proteins. Some of the aforementioned proteins also display antimicrobial activities toward pathogenic microbes.