HYDROPHOBICITY, HYDROPHOBIC MOMENT AND ANGLE SUBTENDED BY CHARGED RESIDUES MODULATE ANTIBACTERIAL AND HEMOLYTIC-ACTIVITY OF AMPHIPATHIC HELICAL PEPTIDES

The hydrophobicity (H), hydrophobic moment (mu) and the angle subtende d by the positively charged helix face (Phi) of a set of model and mag ainin 2 amide peptides with conserved charge and helix propensity have been shown to be effective modulators of antibacterial and haemolytic activity. Except peptides of low hydrophobicity which are inactive, c hanging the parameters has little influence on the activity against Gr am-negative bacteria, thus revealing the dominance of electrostatic in teractions for the effect. However, the increase of H, mu and Phi subs tantially enhances haemolytic and Gram-positive antibacterial activity and is related to a reduction of peptide specificity for Gram-negativ e bacteria. (C) Federation of European Biochemical Societies.