title: Galactoxylomannans of Cryptococcus neoformans.
abstract: Galactoxylomannans (GalXMs) from single isolates of Cryptococcus neoformans serotypes A, B, and D were isolated from culture supernatants and then purified by affinity, ion-exchange, and gel-filtration chromatography. GalXMs are a group of closely related complex polysaccharides. GalXMs from serotypes A (9759 A) and C (3183 C) and an acapsular mutant of serotype D (Cap67 D) have similar galactose, xylose, and mannose molar ratios, but each has some unique structural features. GalXM9759 A and GalXM 3183 C were associated with a starchlike glucan that was removed during purification. Only a trace of glucose was detected in the Cap67 D GalXM. Gas-liquid chromatography-mass spectroscopy of per-O-methylated polysaccharides and 13C nuclear magnetic resonance spectroscopy showed that GalXM is a complex branched polysaccharide. The main chain consists of mannose or galactose or alternating mannose and galactose residues. Xylose is present only as nonreducing termini. Galactofuranose occurs only in 3183 C and Cap67 D, and it is always present as nonreducing termini.
authors.affiliation: Department of Chemistry, Georgia State University, Atlanta 30303.
authors.forename: P G
authors.initials: PG
authors.lastname: James
authors.forename: R
authors.initials: R
authors.lastname: Cherniak
mesh_terms: D002241:Carbohydrates / Q000032:analysis; D002846:Chromatography, Affinity; D003455:Cryptococcus neoformans / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D011134:Polysaccharides; D011135:Polysaccharides, Bacterial / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D002241:Carbohydrates; D011134:Polysaccharides; D011135:Polysaccharides, Bacterial; C043689:galactoxylomannan