The effects of cerebrosides on model membrane shape.

Model membranes composed of phosphatidylcholine, various cerebrosides, and cholesterol have been studied by electron microscopy, deuterium NMR, and phosphorus-31 NMR. Large variations in phosphatidylcholine membrane morphology are observed when cerebrosides are present in phosphatidylcholine bilayers. Large spherical liposomes, small spherical liposomes, and long tubular liposomes are formed, depending on the relative acyl chain lengths of the phosphatidylcholine and cerebroside. In some cases, cholesterol can reverse the morphological effects of cerebrosides. These results suggest that cerebrosides, which are found in high concentrations in certain highly specialized membranes, can affect membrane shape and may be involved in the mechanism of formation of membranes with unusual morphology, e.g. neural myelin and the brush border membrane of the intestinal epithelium.