title: Environment-dependent conformation and antimicrobial activity of a gramicidin S analog containing leucine and lysine residues.
abstract: An analog of gramicidin S, cyclo(-L-Leu-L-Lys-L-Leu-D-Leu-L-Leu-)2, in which four out of five amino acid components of gramicidin S were substituted, has been synthesized. This analog assumes a conformation similar to that of gramicidin S in acidic liposomes and a random conformation in neutral liposomes. The antimicrobial activity of this analog corresponded to one-fourth of that of gramicidin S. A possible mechanism for conformational changes in acidic liposomes is discussed.
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents; D002942:Circular Dichroism; D006096:Gramicidin / Q000138:chemical synthesis* / Q000494:pharmacology; D008051:Lipid Bilayers; D009682:Magnetic Resonance Spectroscopy; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D013696:Temperature
chemical_list: D000900:Anti-Bacterial Agents; D008051:Lipid Bilayers; D006096:Gramicidin