Raman scattering in bilayers of saturated phosphatidylcholines. Experiment and theory

Abstract

Raman spectroscopy was applied to a model biomembrane structure to obtain information about phospholipid hydrocarbon chain ordering. The intensity of the 1130-cm-1 Raman line obtained from a dipalmitoylphosphatidylcholine (DPPC) coarse aqueous dispersion was measured as a function of temperature. The intensities of this line and a reference line were taken as peak areas. The main phase transition together with pretransition was observed. A theory of chain conformations as a function of temperature and rules for the assignment of Raman scattering intensities for this line were constructed. Good agreement with the DPPC experimental data was obtained. Predictions for the intensity of this line as a function of temperature from dimyristoyl- and distearoylphosphatidylcholine dispersions were also made.