1H and 13C nuclear magnetic resonance spectra of the lipids in normal and SV 40 virus-transformed hamster embryo fibroblast membranes

Well resolved ¹H and ¹³C NMR spectra were obtained with normal and SV 40-transformed cell membranes. Estimation of the ratio of ¹³CT₂ values of the normal to transformed cell membranes showed an increased intermolecular motion in the transformed cell membranes. The temperature dependence of the (CH₂)_n line in the ¹H spectra in the temperature range 298–343 °K shows an activation energy for the lateral diffusion of the fluid phospholipid regions in the normal cell membranes while the transformed ones show practically no temperature dependence in this temperature range. The fluidity of the phospholipid region in the transformed cell membrane seems to be significantly higher than that observed in the normal cell material. These data support and extend the findings concerning the mobility of the concanavalin A binding/agglutinating sites on the surface of normal and virus-transformed cells and suggest further approaches to the study of the membrane alterations in tumor cells.