RIBOSOMALLY SYNTHESIZED ANTIMICROBIAL PEPTIDES - THEIR FUNCTION, STRUCTURE, BIOGENESIS, AND MECHANISM OF ACTION

Ribosomally synthesized peptides with antimicrobial activity are produ ced by prokaryotes, plants, and a wide variety of animals, both verteb rates and invertebrates. These peptides represent an important defense against mi cro-organisms. Although the peptides differ greatly in pri mary structures, they are nearly all cationic and very often amphiphil ic, which reflects the fact that many of these peptides kill their tar get cells by permeabilizing the cell membrane. Moreover, many of these peptides may roughly be placed into one of three groups: (1) those th at have a high content of one (or two) amino acid(s), often proline, ( 2) those that contain intramolecular disulfide bonds, often stabilizin g a predominantly beta-sheet structure, and (3) those with amphiphilic regions if they assume an alpha-hell cal structure. Most known riboso mally synthesized antimicrobial peptides have been identified and char acterized during the past 15 years. As a result of these studies, insi ght has been gained into fundamental aspects of biology and biochemist ry such as innate immunity, membrane-protein interactions, and protein modification and secretion. Moreover, it has become evident that thes e peptides may be developed into useful antimicrobial additives and dr ugs. This review presents a broad overview of the main types of riboso mally synthesized antimicrobial peptides produced by eukaryotes and pr okaryotes.