High prevalence of 2-mono- and 2,6-di-substituted manol-terminating sequences among O-glycans released from brain glycopeptides by reductive alkaline hydrolysis

Eur J Biochem. 1999 Aug;263(3):879-88. doi: 10.1046/j.1432-1327.1999.00572.x.


Di- to heptasaccharides isolated from total nondialyzable brain glycopeptides after release by alkaline borohydride treatment have been subjected to mass spectrometric and nuclear magnetic resonance spectroscopic analyses supplemented by TLC-MS analyses of derived neoglycolipids. A family of Manol-terminating oligosaccharides has been revealed which includes novel sequences with a 2, 6-disubstituted Manol: In contrast to the Manol-terminating HNK-1 antigen-positive chains described previously that occur as a minor population [Yuen, C.-T., Chai, W., Loveless, R.W., Lawson, A.M., Margolis, R.U. & Feizi, T. (1997) J. Biol. Chem. 272, 8924-8931], the above oligosaccharides are abundant. The ratio of these compounds to the classical N-acetylgalactosaminitol-terminating oligosaccharides is about 1 : 3. Thus, there appears to be in higher eukaryotes a major alternative pathway related to the yeast-type protein O-mannosylation, the enzymatic basis and functional importance of which now require investigation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Brain Chemistry*
  • Carbohydrate Conformation
  • Carbohydrate Sequence
  • Chromatography, Ion Exchange
  • Chromatography, Thin Layer
  • Glycopeptides / chemistry*
  • Glycopeptides / isolation & purification
  • Indicators and Reagents
  • Mannitol / analysis*
  • Mass Spectrometry
  • Methylation
  • Molecular Sequence Data
  • Oligosaccharides / chemistry*
  • Oligosaccharides / isolation & purification
  • Rabbits


  • Glycopeptides
  • Indicators and Reagents
  • Oligosaccharides
  • Mannitol