NMR studies of membranes composed of glycolipids and phospholipids

Lipid membranes composed of monogalactosyldiacylglycerol (MGDG) and dimyristoylphosphatidylcholine (DMPC) were studied by means of NMR spectroscopy. The macroscopic phase behaviour was investigated by 31P NMR under stationary conditions, whereas microscopic properties such as segmental ordering were probed by two-dimensional 1H–13C separated local field experiments under magic-angle spinning conditions. Our results clearly show that ordering/disordering effects occur for the headgroups as well as for the acyl chains when the sample composition is varied. In particular, the 1H–13C dipolar couplings within the galactose headgroup of MGDG exhibited significant concentration dependence.