Interactions of the antimicrobial β-peptide β-17 with phospholipid vesicles differ from membrane interactions of magainins


R. M. Epand, Department of Biochemistry, 1200 Main Street West, McMaster University Health Sciences Centre, Hamilton, ON, L8N 3Z5 Canada. Fax: 905 521 1397, Tel.: 905 525 9140, E-mail:


We have studied the interaction of β-17, a potent synthetic antimicrobial β-peptide, with phospholipids. We find that unlike other antimicrobial peptides such as magainin II, β-17 facilitates the formation of nonbilayer phases, indicating that the peptide promotes negative curvature. Studies of liposomal leakage also indicate a different mode of membrane interaction relative to magainin II, but both leakage and membrane binding show that β-17, like magainin II, has strong affinity for membranes containing anionic lipids. This is likely to be an important factor contributing to the antimicrobial specificity of the β-peptide.