FIGURE 1.
P454 membrane partition followed by fluorescence. A, ratio of fluorescence intensity at 340 and 380 nm as a function of lipid concentration. The negatively charged small unilamellar vesicles (squares) or large unilamellar vesicles (circles) were made of DOPC/DOPE/DOPG/Chol (4:3:2:1). The P454 fluorescence intensity ratio values were fitted as described under “Materials and Methods,” providing partition coefficient KX and the Hill number (KX = 2.9 × 105, nH = 1.35 for SUVs; KX = 3.9 × 104, nH = 1.04 for LUVs). B, partition coefficient KX as a function of peptide/lipid ratio. Thermodynamic parameters are reported in supplemental Table S1. Error bars correspond to S.D.