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Carbohydrate epitopes in glycoprotein from the opportunistic fungal pathogen Scedosporium apiospermum

Barreto-Bergter, E., Sassaki, G.L., Souza, L.M., Rollin, R.R., Wagner, R., Bittencourt, V.C.B., Lopes, L.C.L., Simas-Tosin, F.F., Noseda, M.D., Gorin, P.A.J.
Carbohydrate polymers 2011 v.85 no.2 pp. 349-355
Pseudallescheria boydii, Scedosporium, electrospray ionization mass spectrometry, epitopes, fungi, glycoproteins, methylation, mycelium, nuclear magnetic resonance spectroscopy, pathogens, peptidoglycans, polymers, trisaccharides
Hot aqueous extraction of Scedosporium apiospermum mycelium provided glycoprotein (HET-PR-Sa) containing 37% protein and Rha, Rib, Ara, Man, Gal, Glc, and GlcNH₂ in a 26:14:17:22:10:5:6 molar ratio. HPSEC showed a mixture. HET-PR-Sa, on reductive, alkaline β-elimination at 25°C, gave nonreducing oligosaccharide epitopes (OLIGO-Sa) from O-linked protein and a polymer (HET-PR-Sa-de-O), which was then β-eliminated at 100°C to give polysaccharide (HET-Sa). The structure of each fraction (methylation, NMR, and ESI-MS analysis) differed from those of a peptidoglycan (PRM-Pb) from mycelium of related, opportunistic pathogen, Pseudallescheria boydii. The predominant nonreducing oligosaccharide formed on β-elimination of PRM-Pb was hexasaccharide 3, whereas those (OLIGO-Sa) from HET-PR-Sa were tetra- 2 and mixed pentasaccharides. Trisaccharide 1 was also identified and is a conserved structure in both fungi. Structural differences confirmed that S. apiospermum is not an anamorph of a P. boydii teleomorph.