Deuterium Nuclear Magnetic Resonance Studies of N-Palmitoylglucosylceramide (Cerebroside) Head Group Structure?

ABSTRACT: Deuterium Fourier-transform nuclear magnetic resonance spectra of N-palmitoyl[2,3,4,6,6-2H,]glucosyl-ceramide, N-palmitoyl [ 1-2H]glucosylceramide, N-palmitoyl-[ 5,6,6-2H,]glucosylceramide, and N-palmit0yl[6,6-~H,]-glucosylceramide have been obtained at 55.3 MHz (corre-sponding to a magnetic field strength of 8.5 T) for lipids as multilamellar dispersions in excess water at 90 "C, above the gel to liquid-crystal phase transition temperature (T, = 82 "C). Spectra were also obtained for these same lipids dispersed with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, 1,2-di-palmitoyl-sn-glycero-3-phosphoethanolamine, and cholesterol, all in excess water at 90 OC. The results are analyzed in terms of a model in which the lipid undergoes fast axial diffusion, together with a "wobbling " of the polar head group, by mathematical methods similar to those used previously for the choline and ethanolamine head groups in phosphatidylcholines Knowledge of the structure and dynamics of cell surface glycosphingolipids may be of considerable importance for understanding functional differences between normal an