Membrane channel formation by antimicrobial protegrins.

Protegrins are small, arginine- and cysteine-rich, beta-sheet peptides with potent activity against bacteria, fungi, and certain enveloped viruses. We report that protegrins form weakly anion-selective channels in planar phospholipid bilayers, induce potassium leakage from liposomes and form moderately cation-selective channels in planar lipid membranes that contain bacterial lipopolysaccharide. The disruption of microbial membranes may be a central attribute related to the host defense properties of protegrins.