Discrimination of neolacto-series gangliosides with alpha2-3- and alpha2-6-linked N-acetylneuraminic acid by nanoelectrospray ionization low-energy collision-induced dissociation tandem quadrupole TOF MS

Anal Chem. 2003 Nov 1;75(21):5719-25. doi: 10.1021/ac0347617.


A combined strategy of thin-layer chromatography immunostaining and negative ion nanoelectrospray low-energy CID mass spectrometry was established for the differentiation of isomeric alpha2-3 and alpha2-6 sialylated neolacto-series monosialogangliosides from human granulocytes. The gangliosides investigated differed in the ceramide moiety by substitution with C16:0 or C24:1 fatty acid and in their oligosaccharide chains due to nLc4 and nLc6 core structures. With respect to the type of sialylation, the homogeneity of the HPLC-purified ganglioside fractions was verified by use of specific anti-Neu5Acalpha2-3Galbeta1-4GlcNAc-R and anti-Neu5Acalpha2-6Galbeta1-4GlcNAc-R antibodies. A clear-cut series of fragment ions for both types of isomeric gangliosides, carrying alpha2-3- and alpha2-6-linked neuraminic acid, respectively, was obtained by low-energy CID. Additionally, a characteristic ring cleavage was detected exclusively in all species with Neu5Acalpha2-6Galbeta1-4GlcNAc terminus, regardless of ceramide fatty acid and oligosaccharide chain lengths. The diagnostic (0,2)X(4/6) ions, generated by ring cleavage of an alpha2-6-linked neuraminic acid are accompanied by a simultaneous decrease of the corresponding Y(4)/Y(6) ions. These results suggest the unequivocal discrimination of individual alpha2-3- and alpha2-6-sialylated neolacto-series monosialogangliosides by distinct fragmentation patterns in low-energy CID tandem MS.

MeSH terms

  • Carbohydrate Conformation
  • Carbohydrate Sequence
  • Chromatography, High Pressure Liquid
  • Chromatography, Thin Layer
  • Disaccharides / analysis*
  • Disaccharides / chemistry
  • Disaccharides / immunology
  • Gangliosides / analysis*
  • Gangliosides / chemistry
  • Gangliosides / immunology
  • Granulocytes / chemistry
  • Humans
  • Immunoenzyme Techniques
  • Ions / chemistry
  • Isomerism
  • Molecular Sequence Data
  • Molecular Structure
  • Molecular Weight
  • Oligosaccharides / chemistry
  • Spectrometry, Mass, Electrospray Ionization* / methods*


  • Disaccharides
  • Gangliosides
  • Ions
  • Oligosaccharides
  • sialogangliosides
  • N-acetylneuraminyl-(2-6)-galactose
  • N-acetylneuraminyl-(2-3)-galactose