Interaction of antimicrobial peptides with biological and model membranes:structural and charge requirements for activity

Species right across the evolutionary scale from insects to mammals use pep tides as part of their host-defense system to counter microbial infection. The primary structures of a large number of these host-defense peptides hav e been determined. While there is no primary structure homology, the peptid es are characterized by a preponderance of cationic and hydrophobic amino a cids. The secondary structures of many of the host-defense peptides have be en determined by a variety of techniques. The acyclic peptides tend to adop t helical conformation, especially in media of low dielectric constant, whe reas peptides with more than one disulfide bridge adopt beta-structures. De tailed investigations have indicated that a majority of these host-defense peptides exert their action by permeabilizing microbial membranes. In this review, we discuss structural and charge requirements for the interaction o f endogenous antimicrobial peptides and short peptides that have been deriv ed from them, with membranes. (C) 1999 Elsevier Science B.V. All rights res erved.