FIGURE 5.

Binding isotherms obtained with POPE/POPG (80:20) vesicles for CM15 analogs spin-labeled at (Δ) C4, (•) C8, (×) C10, and (○) C12. X_b is the molar ratio of bound peptide/accessible lipid, where accessible lipid is one-half the total lipid concentration and C_f is the concentration of peptide remaining free in solution. Straight lines indicate regions of maximum slope used for calculation of K_p. All experiments were done at room temperature in the presence of 20 mM MOPS and 100 mM KCl at pH 7.