Structural characterization of the galactoxylomannan of Cryptococcus neoformans Cap67

Carbohydr Res. 1998 Jan;306(1-2):315-30. doi: 10.1016/s0008-6215(97)10058-1.


The galactoxylomannan (GalXM) obtained from the culture supernatant of an acapsular mutant of Cryptococcus neoformans Cap67 was purified by Concanavalin A affinity, ion-exchange, and gel-filtration chromatographies. The structure of GalXM was determined by methylation analysis and by 1D and 2D NMR spectroscopic studies of the intact polysaccharide and of the oligosaccharide fragments generated by Smith degradation and by acetolysis. GalXM is a complex polysaccharide with an alpha-(1-->6) -galactan backbone. The polysaccharide is branched at c-3 of alternate Gal units of the backbone. C-3 is the point of attachment of the oligosaccharide side chains comprised of alpha-D-Man- (1-->3)-alpha-D-Man-(1-->4)- beta-D-Gal-substituted with zero to three terminal beta-Xyl residues as shown in the following structure: [formula: see text].

Publication types

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

MeSH terms

  • Carbohydrate Sequence
  • Cell Wall / chemistry
  • Chromatography, Affinity
  • Chromatography, Gel
  • Chromatography, Ion Exchange
  • Cryptococcus neoformans / chemistry*
  • Cryptococcus neoformans / genetics
  • Gas Chromatography-Mass Spectrometry
  • Magnetic Resonance Spectroscopy
  • Methylation
  • Molecular Sequence Data
  • Polysaccharides
  • Polysaccharides, Bacterial / chemistry*
  • Polysaccharides, Bacterial / isolation & purification


  • Polysaccharides
  • Polysaccharides, Bacterial
  • galactoxylomannan