Glycosylphosphatidylinositol-anchored fungal polysaccharide in Aspergillus fumigatus.
Galactomannan is a characteristic polysaccharide of the human filamentous fungal pathogen Aspergillus fumigatus that can be used to diagnose invasive aspergillosis. In this study, we report the isolation of a galactomannan fraction associated to membrane preparations from A. fumigatus mycelium by a lipid anchor. Specific chemical and enzymatic degradations and mass spectrometry analysis showed that the lipid anchor is a glycosylphosphatidylinositol (GPI). The lipid part is an inositol phosphoceramide containing mainly C18-phytosphingosine and monohydroxylated lignoceric acid (2OH-C(24:0) fatty acid). GPI glycan is a tetramannose structure linked to a glucosamine residue: Manalpha1-2Manalpha1-2Manalpha1-6Manalpha1-4GlcN. The galactomannan polymer is linked to the GPI structure through the mannan chain. The GPI structure is a type 1, closely related to the one previously described for the GPI-anchored proteins of A. fumigatus. This is the first time that a fungal polysaccharide is shown to be GPI-anchored.
Costachel
Corina
C
Unité des Aspergillus, Institut Pasteur, 75724 Paris cedex 15, France.
Coddeville
Bernadette
B
Latgé
Jean-Paul
JP
Fontaine
Thierry
T
D001232:Aspergillus fumigatus / Q000378:metabolism*; D002241:Carbohydrates / Q000737:chemistry; D002849:Chromatography, Gas; D002850:Chromatography, Gel; D007887:Fabaceae / Q000378:metabolism; D005227:Fatty Acids / Q000737:chemistry; D005690:Galactose / Q000031:analogs & derivatives; D005944:Glucosamine / Q000737:chemistry; D017261:Glycosylphosphatidylinositols / Q000737:chemistry*; D006868:Hydrolysis; D007294:Inositol / Q000737:chemistry; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry; D008351:Mannans / Q000737:chemistry; D008358:Mannose / Q000737:chemistry; D013058:Mass Spectrometry; D009608:Nitrous Acid / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry*; D013997:Time Factors; D010738:Type C Phospholipases / Q000737:chemistry; D043323:alpha-Mannosidase / Q000378:metabolism
D002241:Carbohydrates; D005227:Fatty Acids; D017261:Glycosylphosphatidylinositols; D008055:Lipids; D008351:Mannans; D011108:Polymers; D011134:Polysaccharides; C012990:galactomannan; D007294:Inositol; D010738:Type C Phospholipases; D043323:alpha-Mannosidase; D005944:Glucosamine; D008358:Mannose; C010210:lignoceric acid; D009608:Nitrous Acid; D005690:Galactose