Design and Synthesis of Amphiphilic Basic Peptides with Antibacterial Activity and Their Interaction with Model Membrane

Abstract

Abstract Twelve peptides having 4 to 6 basic amino acid residues in the hydrophobic amino acid sequence were designed and synthesized by the solution method to find peptides with potential activity against Gram-positive and -negative bacteria. CD study of the peptides demonstrated that they formed α-helical structures in the presence of phospholipid liposomes consequently to have amphiphilic property along the axis of helix. The peptides also induced the leakage of the dye carboxyfluorescein from phospholipid vesicles, indicating that the peptides possess the ability to perturb the membrane structure. These peptides showed antibacterial activity against Gram-positive bacteria, and some of them were also active against Gram-negative bacteria. Relationships between the structure and antibacterial activity of the synthetic peptides were discussed.