Abstract
Glycosylphosphatidylinositol (GPI)-anchored proteins have been identified in all eukaryotes. In fungi, structural and biosynthetic studies of GPIs have been restricted to the yeast Saccharomyces cerevisiae. In this article, four GPI-anchored proteins were purified from a membrane preparation of the human filamentous fungal pathogen Aspergillus fumigatus. Using new methodology applied to western blot protein bands, the GPI structures were characterized by ES-MS, fluorescence labeling, HPLC, and specific enzymatic digestions. The phosphatidylinositol moiety of the A. fumigatus GPI membrane anchors was shown to be an inositol-phosphoceramide containing mainly phytosphingosine and monohydroxylated C-24:0 fatty acid. In constrast to yeast, only ceramide was found in the GPI anchor structures of A. fumigatus, even for Gel1p, a homolog of Gas1p in S. cerevisiae that contains diacylglycerol. The A. fumigatus GPI glycan moiety is mainly a linear pentomannose structure linked to a glucosamine residue: Manalpha1-3Manalpha1-2Manalpha1-2Manalpha1-6Manalpha1-4GlcN.
Original language | English |
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Pages (from-to) | 169-177 |
Number of pages | 9 |
Journal | Glycobiology |
Volume | 13 |
Issue number | 3 |
DOIs | |
Publication status | Published - Mar 2003 |