title: 1H-n.m.r. analysis of type-2 chain lacto-gangliosides. Confirmation of structure of a novel cancer-associated fucoganglioside, alpha-NeuAc-(2----6)- beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----3)-beta-D-Galp-(1----4)-[alp ha-L- Fucp-(1----3)]-beta-D-GlcpNAc-(1----3)-beta-D-Galp-(1----4)-beta -D-Glc p- (1----1)-Cer (VI6NeuAcIII3FucnLc6Cer).
abstract: Neolacto-glycosphingolipids, substituted with alpha-NeuAc-(2----3)- and -(2----6)-linked D-Galp residues were analyzed by one- and two-dimensional 1H-n.m.r. spectroscopy at 500 MHz in 49:1 (v/v) di(2H3)methyl sulfoxide-deuterium oxide solution. For the simplest structures analyzed, nLc4Cer, IV3NeuAcnLc4Cer, and IV6NeuAcnLc4Cer, sialosylation-induced changes in shifts of terminal and subterminal core residues were interpretable in terms of existing conformational models. Chemical shifts for H-3e and H-3a of NeuAc characteristic for the type of linkage, were also determined. In addition, regularly reproducible shifts were seen for H-1 and other resonances of terminal and subterminal core residues of all structures tested. Chemical-shift correlations proved to be useful in elucidating the structure of a unique ganglioside bearing an internal beta-D-Galp-(1----4)-[alpha-L-Fucp-(1----3)]-beta-D-GlcpNAc-(1---- 3) residue ("X-trisaccharide") with an alpha-NeuAc-(2----6)-substituted terminal group.
authors.affiliation: Program of Biochemical Oncology/Membrane Research, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: S B
authors.initials: SB
authors.lastname: Levery
authors.forename: E
authors.initials: E
authors.lastname: Nudelman
authors.forename: R
authors.initials: R
authors.lastname: Kannagi
authors.forename: F W
authors.initials: FW
authors.lastname: Symington
authors.forename: N H
authors.initials: NH
authors.lastname: Andersen
authors.forename: H
authors.initials: H
authors.lastname: Clausen
authors.forename: M
authors.initials: M
authors.lastname: Baldwin
authors.forename: S
authors.initials: S
authors.lastname: Hakomori
mesh_terms: D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D005732:Gangliosides; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data
chemical_list: D005732:Gangliosides; C031153:fucogangliosides