The impact of palmitoyl glycyl-histidyl-lysine on phospholipid model membranes

Abstract

BackgroundPalmitoyl glycyl-histidyl-lysine (Pal-GHK), a peptide amphiphile derived from the GHK tripeptide, has gained attention for its diverse bioactive properties and applications in skincare formulations. This study delves into the interactions and effects of Pal-GHK on phospholipid model membranes. Using a thin film hydration-sonication method, Pal-GHK and hydrogenated soy phosphatidylcholine (HSPC) were combined to create lipid vesicles. MethodsVarious analytical techniques, including dynamic light scattering (DLS), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), fluorescence polarization (FP), and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), were employed to comprehensively assess the impact of Pal-GHK on the lipid bilayer domain. Significant FindingsThe results reveal insights into the size, zeta potential, storage stability, morphology, thermotropic phase behavior, molecular arrangement, and lipid ordering within the HSPC membranes in the presence of Pal-GHK. The introduction of Pal-GHK increased vesicle size, surface charge density, and storage stability in HSPC-rich vesicles. The addition of Pal-GHK dominated the endothermic phase behavior of the lipid vesicles and increased the proportion of gauche conformation in the acyl chains of HSPC, inducing molecular fluidity in the hydrophobic region of the lipid membrane in its gel state. These findings contribute to our understanding of the interactions between Pal-GHK and lipid model membranes, holding significance for various scientific disciplines and potential applications.