To help determine how amino acid sequence can influence ionic conduction properties in α- helical structures, we have synthesized and studied three closely related, channel-forming peptides. The sequences are based on a 21-residue amphiphilic Leu-Ser-Ser-Leu-Leu-Ser- Leu heptad repeat motif and differ in having either neutral, negatively, or positively charged N-termini. The channels formed by the neutral peptide are modestly cation selective and ...
