Ceramides/Cholesterol Mixtures as Characterized by FT Raman Spectroscopy

Ceramides IV, hydrated ceramides IV and ceramides/cholesterol mixtures were studied by FT Raman spectroscopy and differential scanning calorimetry (DSC). The temperature-dependence of the conformationally sensitive bands in the CH2 stretching region was used to estimate the degree of order of hydrocarbon chains in terms of the relative population of trans and gauche conformers. The temperature and width of the phase transition, derived from Raman data, are similar to those from the DSC studies. The addition of both cholesterol and water lowers the phase transition temperature and broadens the transition range.