Sphingolipids of the mycopathogen Sporothrix schenckii: identification of a glycosylinositol phosphorylceramide with novel core GlcNH(2)alpha1-->2Ins motif.
Acidic glycosphingolipid components were extracted from the yeast form of the dimorphic mycopathogen Sporothrix schenckii. Two minor and the major fraction from the yeast form (Ss-Y1, -Y2, and -Y6, respectively) have been isolated. By a combination of 1- and 2-D 1H-nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization mass spectrometry (ESI-MS), and gas chromatography/mass spectrometry (GC/MS), Ss-Y6 was determined to be triglycosylinositol phosphorylceramide with a novel glycan structure, Manalpha1-->3Manalpha1-->6GlcNH(2)alpha1-->2Ins1-P-1Cer (where Ins=myo-inositol, P=phosphodiester). While the GlcNH(2)alpha1-->6Ins1-P- motif is found widely distributed in eukaryotic GPI anchors, the linkage GlcNH(2)alpha1-->2Ins1-P- has not been previously observed in any glycolipid. Ss-Y1 and Ss-Y2 were both found to have the known glycan structure Manalpha1-->3Manalpha1-->2Ins1-P-1Cer. Together with the results of a prior study [Toledo et al. (2001) Biochem. Biophys. Res. Commun. 280, 19-24] which showed that the mycelium form expresses GIPCs with the structures Manalpha1-->6Ins1-P-1Cer and Manalpha1-->3Manalpha1-->6Ins1-P-1Cer, these results demonstrate that S. schenckii can synthesize glycosylinositol phosphorylceramides with at least three different core linkages.
Department of Biochemistry, Universidade Federal de São Paulo/Escola Paulista de Medicina, SP, Brazil.
M S
MS
Toledo
S B
SB
Levery
A H
AH
Straus
H K
HK
Takahashi
D020816:Amino Acid Motifs; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D008401:Gas Chromatography-Mass Spectrometry; D006028:Glycosphingolipids / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008969:Molecular Sequence Data; D011487:Protein Conformation; D021241:Spectrometry, Mass, Electrospray Ionization; D013107:Sphingolipids / Q000737:chemistry*; D013175:Sporothrix / Q000737:chemistry*; D013997:Time Factors
D006028:Glycosphingolipids; D013107:Sphingolipids; C025524:inositolphosphoceramides