Taxonomic group: fungi / Ascomycota
(Phylum: Ascomycota)
Associated disease: respiratory diseases [ICD11:
12 
];
aspergillosis [ICD11:
1F20 
, ICD11:
XN0WC 
];
infection due to Aspergillus fumigatus [ICD11:
XN5Z7 
]
The structure was elucidated in this paperNCBI PubMed ID: 12851285Publication DOI: 10.1093/glycob/cwg089Journal NLM ID: 9104124Publisher: IRL Press at Oxford University Press
Correspondence: eliana.bergter

micro.ufrj.br
Institutions: Instituto de Microbiologia Professor Paulo de Góes, CCS Universidade Federal do Rio de Janeiro (UFRJ), 21944-970, Rio de Janeiro, RJ, Brasil, Instituto Biomedico, Universidade do Rio de Janeiro, 20211-040, Rio de Janeiro, RJ, Brasil, Centro Nacional de Ressonância Magnética Nuclear, Departamento de Bioquímica, ICB/UFRJ, 21941-590, Rio de Janeiro, RJ, Brasil, Institute for Medical Physics and Biophysics, University of Münster, Robert-Koch Str 31, D-48149, Münster, Germany, University of Bielefeld, Bielefeld, Germany, Departamento de Bioquímica, Universidade Federal do Paraná (UFPR), D-33501, 81531-990, Curitiba, Paraná, Brazil
O-linked oligosaccharide groups ranging from di- to hexasaccharide were beta-eliminated by mild alkaline treatment under reducting conditions from the peptidogalactomannan of Aspergillus fumigatus mycelial cell wall. The resulting reduced oligosaccharides, which were the minor components of the peptidogalactomannan fraction, were fractionated to homogeneity by successive gel filtration and high-performance liquid chromatography. Their primary structures were determined based on a combination of techniques including gas chromatography, ESI-QTOF-MS, H-1 COSY and TOCSY, and H1-C13 HMQC NMR spectroscopy and methylation analysis, to be: α-Glcp-(1→6)-Man-ol, β-Galf-(1→6)-α-Manp-(1→6)-Man-ol, β-Galf-(1→5)-β-Galf-(1→6)-α-Manp-(1→6)-Man-ol and β-Galf-(1→5)-[β-Galf-(1→5)](3)-β-Galf-(1→6)-Man-ol. The β-Galf containing oligosaccharides have not been previously described as fungal O-linked oligosaccharides. The peptidogalactomannan is antigenic and was recognized by human sera of patients with aspergillosis when probed by ELISA, but de-O-glycosylation rendered a 50% decrease in its reactivity. Furthermore, when tested in a hapten inhibition test, the isolated oligosaccharide alditols were able to block, on a dose-response basis, recognition between human sera and the intact peptidogalactomannan. The immunodominant epitopes were present in the tetra- and hexasaccharide, which contain a β-Galf-(1→5)-β-Galf terminal group. These results suggest that the O-glycosidically linked oligosaccharide chains, despite being the less abundant carbohydrate component of the A. fumigatus peptidogalactomannan, may account for a significant part of its antigenicity, other than the known activity associated with the galactomannan component.
NMR, ELISA, Aspergillus fumigatus, ESI-QTOF-MS, O-linked α-Glcp and α-Galf-oligosaccharides
Structure type: oligomer
Location inside paper: abstract, p.687, table VII, fraction OA1
Trivial name: O-linked oligosaccharide
Compound class: cell wall polysaccharide
Contained glycoepitopes: IEDB_114705,IEDB_130701,IEDB_136095,IEDB_137472,IEDB_144983,IEDB_152206,IEDB_190606,IEDB_885812,IEDB_983930,SB_44,SB_67,SB_72
Methods: 13C NMR, 1H NMR, methylation, NMR-2D, GC-MS, sugar analysis, ELISA, acid hydrolysis, HPLC, immunochemical methods, extraction, HPTLC, ESI-QTOF-MS, mild alkaline treatment, beta-elimination
Biological activity: Inhibitor, according to haptene inhibition test.
Comments, role: Peptidogalactomannan after mild alkaline treatment under reducing conditions.
Related record ID(s): 41356, 41357, 41359, 41360
NCBI Taxonomy refs (TaxIDs): 746128Reference(s) to other database(s): GTC:G59541HN
Show glycosyltransferases
NMR conditions: in D2O at 313 K
[as TSV]
13C NMR data:
Linkage Residue C1 C2 C3 C4 C5 C6
6,6,5 bDGalf 108.7 83.0 78.3 84.6 ? 64.6
6,6 bDGalf 109.7 83.0 78.3 83.9 77.4 62.8
6 aDManp 103.1 72.0 ? ? ? 68.6
xDMan-ol 64.5 ? ? ? ? 72.0
1H NMR data:
Linkage Residue H1 H2 H3 H4 H5 H6
6,6,5 bDGalf 5.19 4.12 4.04 4.04 ? 3.66
6,6 bDGalf 4.99 4.12 4.04 4.07 3.93 3.77
6 aDManp 4.96 3.95 ? ? ? 3.64
xDMan-ol 3.83 ? ? ? ? ?
1H/13C HSQC data:
Linkage Residue C1/H1 C2/H2 C3/H3 C4/H4 C5/H5 C6/H6
6,6,5 bDGalf 108.7/5.19 83.0/4.12 78.3/4.04 84.6/4.04 ?/? 64.6/3.66
6,6 bDGalf 109.7/4.99 83.0/4.12 78.3/4.04 83.9/4.07 77.4/3.93 62.8/3.77
6 aDManp 103.1/4.96 72.0/3.95 ?/? ?/? ?/? 68.6/3.64
xDMan-ol 64.5/3.83 ?/? ?/? ?/? ?/? 72.0/?
1H NMR data:
| Linkage | Residue | H1 | H2 | H3 | H4 | H5 | H6 |
| 6,6,5 | bDGalf | 5.19 | 4.12 | 4.04 | 4.04 | ? | 3.66 |
| 6,6 | bDGalf | 4.99 | 4.12 | 4.04 | 4.07 | 3.93 | 3.77 |
| 6 | aDManp | 4.96 | 3.95 | ? | ? | ? | 3.64 |
| | xDMan-ol | 3.83 | ? | ? | ? | ? | ? |
|
13C NMR data:
| Linkage | Residue | C1 | C2 | C3 | C4 | C5 | C6 |
| 6,6,5 | bDGalf | 108.7 | 83.0 | 78.3 | 84.6 | ? | 64.6 |
| 6,6 | bDGalf | 109.7 | 83.0 | 78.3 | 83.9 | 77.4 | 62.8 |
| 6 | aDManp | 103.1 | 72.0 | ? | ? | ? | 68.6 |
| | xDMan-ol | 64.5 | ? | ? | ? | ? | 72.0 |
|
 The spectrum also has 8 signals at unknown positions (not plotted). |
There is only one chemically distinct structure: