Conformational features of lipids and proteins in myelin membranes using Raman and infrared spectroscopy

Myelin membrane and its proteolipid protein (PLP) have been examined by infrared and Raman spectroscopy to provide information about the secondary structure of proteins and conformation of lipid chains. Splitting of the amide I modes in the vibrational spectra and locations of amide A, I, II, III and V bands indicate that the polypeptide arrangement in both membrane systems is mainly helical. The β-form is also present, its amount being higher in PLP. Raman spectra in the CC and CH stretching regions show significant differences concerning intra- and inter-chain lipid order, which is greater in PLP.