Figure 3. Principal component analysis of the model fitted main phase transitions of LUVs added with peptides at 4 mol% highlight similarities on membranes thermal behaviors.

A matrix describing the effect of peptides on the transition temperature (Tm), enthalpy (ΔH) and cooperativity (ΔH_VH) of the broad and sharp components of DMPC and 2∶1 DMPC:DMPG LUV thermal transitions was assembled and standardized (Table S2) and a PCA was applied to the resulting data. Additionally, the coordinates of peptides in the first three principal components were submitted to a mixture modeling clustering algorithm, resulting in an optimal of three peptide clusters, shown here in different colors (Fig. S3). Thermograms demonstrating the effect of selected peptides on the main phase transition of membranes are shown as representative examples: HSP-4 on (a) 2∶1 DMPC:DMPG and (b) DMPC LUVs represents cluster 3, in black, the IAP Q8RW88(70–95) on (c) 2∶1 DMPC:DMPG and (d) DMPC LUVs represents cluster 1, in green, and penetratin added to (e) DMPC and (f) 2∶1 DMPC:DMPG LUVs represents cluster 2, in grey. Group borders are illustrational.