Structure and function of membrane-lytic peptides

This article reviews the membrane interactions of a variety of peptides including alamethicin, melittin, cecropins, magainins, and defensins. The biological activities of the peptides are discussed and correlated to results from biophysical and structural studies. A picture emerges that allows one to understand the mechanisms of lysis and the regulation of the peptides' activities. Specific peptide-lipid interactions are particularly important in the case of antibiotic peptides, which affect the functionality of bacterial membranes, fungal membranes, or both but leave the bilayers of higher organisms, including those of the host cells, intact. Several models are presented and discussed in view of the ensemble of experimental data. These include the barrel stave, the wormhole, the carpet, and the detergent-like model.