title: Molecular dynamics of sugars bound to wheat germ agglutinin, as studied by deuterium nuclear magnetic resonance.
abstract: Deuterium nuclear magnetic resonance is used to delineate the molecular dynamics of sugars bound to a lectin. 2H spin-spin relaxation times (from linewidth measurements) and reorientational correlation times are determined for N-acetylglucosamine specifically-labeled with 2H in the N-acetyl group and at carbon-3 of the pyranoside ring, in the presence and absence of wheat germ agglutinin. The correlation time for the 2H-label of N-acetylglucosamine-3-2H in the bound state is the same as that of the protein (3 X 10(-8)S), indicating that the six-membered ring has negligible motional freedom relative to the protein. The correlation time for the C2H3 group of N-acetyl-2H3-glucosamine (1.7 X 10(-9)S) shows that the N-acetyl side chain is also immobilized in the binding site, the only motion available being rotation of the C2H3 group about its threefold axis.
mesh_terms: D000117:Acetylglucosamine; D002236:Carbohydrate Conformation; D055598:Chemical Phenomena; D002621:Chemistry; D003903:Deuterium; D005944:Glucosamine / Q000031:analogs & derivatives; D007700:Kinetics; D037102:Lectins; D009682:Magnetic Resonance Spectroscopy; D011485:Protein Binding; D011487:Protein Conformation; D014909:Wheat Germ Agglutinins
chemical_list: D037102:Lectins; D014909:Wheat Germ Agglutinins; D003903:Deuterium; D005944:Glucosamine; D000117:Acetylglucosamine