Antimicrobial properties of a lipid interactive α-helical peptide VP1 against Staphylococcus aureus bacteria

Theoretical analysis indicates that peptide VP1 forms a membrane interactive amphiphilic α-helix with antibacterial properties. Fourier transform infra-red based analyses showed VP1 to be α-helical (45%) in the presence of vesicle mimics of membranes from Staphylococcus aureus and to induce increases in the fluidity of these vesicles, as indicated by a rise in wavenumber of circa 0.5 to 1.0 cm− 1. The peptide induced surface pressure increases of 5 mN m− 1 in monolayer mimics of S. aureus membranes confirm the formation of a membrane interactive α-helix. These interactions appeared to involve significant hydrophobic and electrostatic contributions as VP1 induced comparable surface pressure changes in anionic (5.5 mN m− 1) and zwitterionic (4 mN m− 1) lipid monolayers. It is suggested that whilst efficacy requires further sequence specific information, the peptides generic structure provides the basis for its broad antimicrobial activity.