Deuterium NMR studies of cerebroside-phospholipid bilayers

2H-NMR was used to probe the interaction of non-hydroxy fatty acid cerebroside and 2-hydroxy fatty acid cerebroside with the polar head group and with the acyl chains of dipalmitoylphosphatidylcholine in unsonicated bilayers. It is shown that the interior of the bilayer exhibits uniformly increasing orientational order as the concentration of both types of cerebroside increases, whereas the surface of the bilayer, as reflected by the head group motion, becomes disordered. The extent of the disorder at the surface is dependent upon the type and concentration of the cerebroside. These results are discussed in terms of hydrogen-bonding interactions.