TY - JOUR
T1 - Comparison of the 13C-n.m.r. spectra of gangliosides GM1 with those of GM1-oligosaccharide and asialo-GM1
AU - Sillerud, Laurel O.
AU - Yu, Robert K.
N1 - Funding Information:
*This work was supported by Grant NS 11853 from the National Institutes of Health and by grant RG1289-A-2 from the Multiple Sclerosis Foundation. tTo whom reprint requests should be addressed at The Department of Neurology, Yale University, New Haven, Connecticut 06510. ZThe following ganglioside nomenclature used in this report was recommended by the IUPAC-IUB commission on Biochemical Nomenclature: G&II, I13NeuAc-GgOseKer (1); GMIOS, I13NeuAc-GgOse4 (2); asialo-G&n (ASG&, GgOseKer (3); Gmb, IV3NeuAc-GgOse&er (7); GYP, 13-NeuAc-GalCer (8); GYP, IIsNeuAc-LacCer (9); GMZ,I 13NeuAc-GgOseKer (10); Gma, IV3NeuAc,I13NeuAc-GgOse&er (4); GD~B, IIs(NeuAc)s-GgOseKer (5); and Gw, IV3NeuAc,I13(NeuAc)s-GgOseKer (6).
PY - 1983/3/1
Y1 - 1983/3/1
N2 - The 13C-n.m.r. spectra of asialo-GM1 and GM1-oligosaccharide are completely assigned and compared to those previously found for intact GM1 and for the series GM4, GM3, GM2, GM1, GD1a, GD1b, and GT1b. Removal of the ceramide residue from GM1 liberated a free, reducing aldehyde group, which was reflected in a doubling of the 13C-n.m.r. signals assignable to the d-glucose residue because of α,β equilibrium. The spectrum of asialo-GM1 lacks the resonances from the sialic acid residue, as expected; in addition, several resonances from the neutral gangliotetraglycosyl residue shifted to different field positions after removal of sialic acid from GM1. These resonances include that of C-4 of the inner β-d-galactosyl residue, and C-1 of the 2-acetamido-2-deoxy-d-galactosyl residue that is near the site of attachment of the sialosyl residue. The differences between the chemical shifts of the carbon resonances of oligomeric and monomeric saccharides, termed linkage shifts, provide a quantitative assignment aid. They are ∼ 1 3 of those for residues linked to sialic acid than those for residues linked to the neutral hexose chain. Correlations among linkage shifts for pairs of glycosidically-linked carbon atoms for asialo-GM1 and GM1-oligosaccharide were compared with those for the series of gangliosides GM4 to GT1b, and differences are noted for resonances for carbon atoms near the sialic acid residue. The spectrum of ganglioside GM1b, a positional isomer of GM1 whose 13C-n.m.r. spectrum has not yet been observed, is predicted.
AB - The 13C-n.m.r. spectra of asialo-GM1 and GM1-oligosaccharide are completely assigned and compared to those previously found for intact GM1 and for the series GM4, GM3, GM2, GM1, GD1a, GD1b, and GT1b. Removal of the ceramide residue from GM1 liberated a free, reducing aldehyde group, which was reflected in a doubling of the 13C-n.m.r. signals assignable to the d-glucose residue because of α,β equilibrium. The spectrum of asialo-GM1 lacks the resonances from the sialic acid residue, as expected; in addition, several resonances from the neutral gangliotetraglycosyl residue shifted to different field positions after removal of sialic acid from GM1. These resonances include that of C-4 of the inner β-d-galactosyl residue, and C-1 of the 2-acetamido-2-deoxy-d-galactosyl residue that is near the site of attachment of the sialosyl residue. The differences between the chemical shifts of the carbon resonances of oligomeric and monomeric saccharides, termed linkage shifts, provide a quantitative assignment aid. They are ∼ 1 3 of those for residues linked to sialic acid than those for residues linked to the neutral hexose chain. Correlations among linkage shifts for pairs of glycosidically-linked carbon atoms for asialo-GM1 and GM1-oligosaccharide were compared with those for the series of gangliosides GM4 to GT1b, and differences are noted for resonances for carbon atoms near the sialic acid residue. The spectrum of ganglioside GM1b, a positional isomer of GM1 whose 13C-n.m.r. spectrum has not yet been observed, is predicted.
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U2 - 10.1016/0008-6215(83)88234-2
DO - 10.1016/0008-6215(83)88234-2
M3 - Article
C2 - 6839313
AN - SCOPUS:0020730180
SN - 0008-6215
VL - 113
SP - 173
EP - 188
JO - Carbohydrate Research
JF - Carbohydrate Research
IS - 2
ER -