Raman and infrared spectroscopic study of myelin membranes

Abstract Raman and infared spectroscopy have been applied to the study of myelin membranes and their proteolipid (PLP) and delipidated proteolipid apoprotein (PLA). Peak hight intensity parameters of Raman spectra in the CC and CH stretching regions indicate that inter and intrachain order is greater in PLP than in myelin. It is concluded that the polypeptide arrangement in myelin, PLP and PLA is mainly helical, but the half-width of the νNH infrared bands suggests that some distortion of the helix occurs. In all samples β-form is also present, the amount of this structure being higher in PLA.