Antimicrobial peptides from marine organisms

Abstract

Antimicrobial peptides (AMP), also known as host defense peptides or alarmins, are among the first lines of defense against infection in many organisms. Marine organisms have proved to be a rich source of AMPs, and several uniquely structured marine AMPs have been isolated using biochemical, in silico and genetic approaches. Hemolymph is the main source of AMPs in marine invertebrates, although other tissues may also contain these peptides. Based on their three-dimensional structure, AMPs may be classified into peptides with ?-helix structures, peptides with ?-sheets and cysteine residues, peptides enriched for modified and rare amino acids, and peptides with ring structure amino acids. This chapter describes AMPs of each structure, in terms of their antibacterial, antiviral, antifungal, insecticidal, nematicidal, and immunomodulatory functions. It is hoped that the diversity of marine AMPs may facilitate the identification of effective substitutes to existing antibiotics, thereby helping to minimize the development of antibiotic-resistant pathogen strains in response to the continuous application of a single antibiotic therapy.