Fig. 2.

Melittin helices and lipid bilayers in fully hydrated multilayers of peptide–lipid (DOPC/DOPG at a 7:3 ratio) mixtures in the P/L. (A) Membrane thickness, PtP, as a function of the P/L measured by lamellar diffraction. The PtP linearly decreases with the P/L until P/L*∼1:45 is attained. (B) Same samples were measured by the method of OCD to determine the fraction of melittin helices oriented normal to the plane of bilayers (the remaining fraction was parallel to the plane). The fraction is linear when plotted against 1/(P/L) (31) for a P/L above a transition point, P/L*∼1:45. The error bars are the ranges of reproducibility using two to three independently prepared samples.