Structure and dynamics of the sialic acid moiety of GM3-ganglioside at the surface of a magnetically oriented membrane.
13C-NMR techniques in oriented bilayer systems composed of DMPC and CHAPSO have been used to measure dipolar interactions between 13C-13C and 13C-1H pairs located in the sialic acid moiety of ganglioside GM3. These interactions are reduced to a structural and motional model for the headgroup of this glycolipid using an order matrix approach. The analysis shows an average structure possessing a high degree of order and is most consistent with structures that are well extended from the membrane surface. Saturation of the ganglioside environment with high concentrations of Ca2+ (0.28 M) produces a small perturbation of the headgroup. GM3 dissolved in a DMPC/CHAPSO system can also be demonstrated to bind wheat germ agglutinin (WGA). The minimal perturbation of structure-dependent parameters suggests that the dominant structure of the sialic acid moiety in the isolated membrane system is favored for binding by the protein.
Aubin
Y
Y
Department of Chemistry, Yale University, New Haven, Connecticut 06511.
Ito
Y
Y
Paulson
J C
JC
Prestegard
J H
JH
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002793:Cholic Acids; D003902:Detergents; D004134:Dimyristoylphosphatidylcholine; D005679:G(M3) Ganglioside / Q000737:chemistry* / Q000378:metabolism; D008051:Lipid Bilayers / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D015394:Molecular Structure; D019158:N-Acetylneuraminic Acid; D012794:Sialic Acids / Q000737:chemistry* / Q000378:metabolism; D014909:Wheat Germ Agglutinins / Q000378:metabolism
D002793:Cholic Acids; D003902:Detergents; D005679:G(M3) Ganglioside; D008051:Lipid Bilayers; D012794:Sialic Acids; D014909:Wheat Germ Agglutinins; C048531:chapso; D019158:N-Acetylneuraminic Acid; D004134:Dimyristoylphosphatidylcholine