The opportunistic fungal pathogen Scedosporium prolificans: carbohydrate epitopes of its glycoproteins.
Isolated from the mycelium of Scedosporium prolificans were complex glycoproteins (RMP-Sp), with three structurally related components (HPSEC). RMP-Sp contained 35% protein and 62% carbohydrate with Rha, Ara, Man, Gal, Glc, and GlcNH(2) in a 18:1:24:8:6:5 molar ratio. Methylation analysis showed mainly nonreducing end- of Galp (13%), nonreducing end- (9%), 2-O- (13%), and 3-O-subst. Rhap (7%), nonreducing end- (11%), 2-O- (10%), 3-O- (14%), and 2,6-di-O-subst. Manp units (13%). Mild reductive beta-elimination of RMP-Sp gave alpha-l-Rhap-(1-->2)-alpha-l-Rhap-(1-->3)-alpha-l-Rhap-(1-->3)-alpha-d-Manp-(1-->2)-d-Man-ol, with Man-ol substituted at O-6 with beta-d-Galp units, a related pentasaccharide lacking beta-d-Galp units, and beta-d-Galp-(1-->6)-[alpha-d-Manp-(1-->2)]-d-Man-ol in a 16:3:1w/w ratio. Traces of Man-ol and Rha-ol were detected. ESI-MS showed HexHex-ol and Hex(3-6)Hex-ol components. Three rhamnosyl units were peeled off successively from the penta- and hexasaccharide by ESI-MS-MS. The carbohydrate epitopes of RMP-Sp differ from those of the glycoprotein of Pseudallescheria boydii, a related opportunistic pathogen.
Barreto-Bergter
E
E
Instituto de Microbiologia, C.C.S., Universidade Federal do Rio de Janeiro, 21944-590 Rio de Janeiro, RJ, Brazil.
Sassaki
G L
GL
Wagner
R
R
Souza
L M
LM
Souza
M V A R
MV
Pinto
M R
MR
da Silva
M I D
MI
Gorin
P A J
PA
D002240:Carbohydrate Sequence; D000939:Epitopes / Q000737:chemistry* / Q000276:immunology*; D006023:Glycoproteins / Q000737:chemistry* / Q000276:immunology*; D009682:Magnetic Resonance Spectroscopy; D009844:Oligosaccharides / Q000737:chemistry; D021681:Scedosporium / Q000737:chemistry / Q000276:immunology* / Q000472:pathogenicity*; D021241:Spectrometry, Mass, Electrospray Ionization
D000939:Epitopes; D006023:Glycoproteins; D009844:Oligosaccharides