Synthetic peptides form ion channels in artificial lipid bilayer membranes

Ion permeability of cell membranes is considered to be mediated by ion channels. The synthesis and testing of four peptides having the sequence (Leu-Ser-Leu-Gly)n and expected to form beta126,6-helical ion channels in lipid bilayer membranes is reported. The two peptides capable of forming helices four turns in length have been demonstrated to form ion channels in an artificial lipid bilayer membrane system. The ion selectivity of the channels is consistent with the predicted beta12-helical model in which ions traversing the channel are coordinated by serine hydroxyl groups arrayed in the interior of the channel.