Glycosylinositolphosphoceramides in Aspergillus fumigatus

Fungal glycosylinositolphosphoceramides (GIPCs) are involved in cell growth and fungal-host interactions. In this study, six GIPCs from the mycelium of the human pathogen Aspergillus fumigatus were purified and characterized using Q-TOF mass spectrometry and H-1, C-13, and P-31 NMR. All structures have the same inositolphosphoceramide moiety with the presence of a C-18:0-phytosphingosine conjugated to a 2-hydroxylated saturated fatty acid (2-hydroxy-lignoceric acid). The carbohydrate moiety defines two types of GIPC. The first, a mannosylated zwitterionic glycosphingolipid contains a glucosamine residue linked in alpha 1-2 to an inositol ring that has been described in only two other fungal pathogens. The second type of GIPC presents an alpha-Manp-(1 -> 3)-alpha-Manp-(1 -> 2)-IPC common core. A galactofuranose residue is found in four GIPC structures, mainly at the terminal position via a beta 1-2 linkage. Interestingly, this galactofuranose residue could be substituted by a choline-phosphate group, as observed only in the GIPC of Acremonium sp., a plant pathogen.