Structural studies of a cell wall polysaccharide of Trichosporon asahii containing antigen II

Abstract

The structure of a cell-wall polysaccharide containing antigen II from Trichosporon asahii was investigated. A purified glucuronoxylomannan (GXM) antigen was found to contain O-acetyl groups that contribute to the serological reactivity. The structure of GXM was analyzed by partial acid hydrolysis, methylation analysis, controlled Smith degradation, NMR studies, and fluorophore-assisted carbohydrate electrophoresis. GXM has an a- (

Structural and functional properties of the Trichosporon asahii glucuronoxylomannan

“…Structural and serological analyses have shown similarities and differences between the polysaccharides from Cryptococcus and Trichosporon (Ichikawa et al, 2001; Melcher et al, 1991). Depending on the species and related serotype, the building motifs of the cryptococcal GXM vary in complexity (Cherniak et al, 1998).…”

“…Depending on the species and related serotype, the building motifs of the cryptococcal GXM vary in complexity (Cherniak et al, 1998). The repeating motif of the Trichosporon GXM appears to be even more complex (Ichikawa et al, 2001). A comparison with the Cryptococcus motifs reveals that the Trichosporon polysaccharide manifested more variability in its structural features.…”

“…Glucuronoxylomannan (GXM) is a cell wall-associated and secreted polysaccharide produced by species of the genus Trichosporon (Ichikawa et al, 2001; Karashima et al, 2002) and Cryptococcus (reviewed in Bose et al (2003)). In T. asahii ,GXM building blocks consist of an α1,3- d -mannan-like hexasaccharide substituted with one β1,2-glucopyranosyluronic acid residue and six β- d -xylopyranosyl units (Fig.…”

“…In T. asahii ,GXM building blocks consist of an α1,3- d -mannan-like hexasaccharide substituted with one β1,2-glucopyranosyluronic acid residue and six β- d -xylopyranosyl units (Fig. 1 and Ichikawa et al, 2001). Xylosylation includes O -2, O -4 and O -6 substitutions of the mannose residues.…”

“…Although several structural aspects of T. asahii GXM have been described (Ichikawa et al, 2001), the functions of this polysaccharide for physiology and pathogenesis of Trichosporon spp. are virtually unknown.…”