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 α-(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 α-D-man- (1→3)-α-D-man-(1→4)- β-D-Gal-substituted with zero to three terminal β-Xyl residues as shown in the following structure: [formula: see text].
structural, characterization, polysaccharide, polysaccharide structure, 2D NMR spectroscopy, Cryptococcus, Cryptococcus neoformans, galactoxylomannan (GalXM)
NCBI PubMed ID: 9691456Publication DOI: 10.1016/S0008-6215(97)10058-1Journal NLM ID: 0043535Publisher: Elsevier
Correspondence: cherniak@gsu.edu.
Institutions: Complex Carbohydrate Research Center, University of Georgia, 220 Riverbend Road, Athens, GA 30602, USA, Department of Chemistry (LBCS), Georgia State University, Atlanta, GA 30303-3083, USA, Department of Chemistry LBCS , Georgia State University, Atlanta, GA 30303-3083, USA, Complex Carbohydrate Research Center, UniOersity of Georgia, 220 Riverbend Road, Athens, GA 30602, USA, Department of Chemistry LBCS, Georgia State University, Atlanta, GA 30303-3083, USA
Methods: 13C NMR, 1H NMR, methylation, GLC-MS, gel filtration, NMR-2D, NMR, ESI-MS, GLC, HPAEC, Smith degradation, ion-exchange chromatography, gel chromatography, acetolysis, TOCSY, methylation analysis, reduction, DQF-COSY, NOESY, ion exchange chromatography, GHSQC, GHMBC
Found