Structural analysis of novel rhamnose-branched oligosaccharides from the glycophosphosphingolipids of Leptomonas samueli.
Mild alkaline hydrolysis of the glycophosphosphingolipids of the protozoan Leptomonas samueli liberated several phosphoinositol-containing oligosaccharides (PI-oligosaccharides), which were purified by high performance anion exchange chromatography. The oligosaccharides in the resulting four fractions were characterized by methylation analysis, fast atom bombardment mass spectrometry and two-dimensional nuclear magnetic resonance spectroscopy. The oligosaccharides contain the core structure Man alpha (1-4)GlcN alpha (1-6)-myo-inositol-1-OPO3, and are substituted with 2 mol of 2-aminoethylphosphonate per mol of oligosaccharide. The nonreducing ends of the oligosaccharides were terminated by rhamnose branched neutral and acidic xylose-containing penta-, hexa-, hepta- and octasaccharides, of which the three most abundant were shown to have the structures: [formula: see text] More tentative structures are also proposed for three minor oligosaccharides.
Previato
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Departamento de Microbiologia Geral, Universidade Federal do Rio de Janeiro, Brasil.
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Jones
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D000818:Animals; D002240:Carbohydrate Sequence; D006028:Glycosphingolipids / Q000737:chemistry*; D017261:Glycosylphosphatidylinositols / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry*; D012210:Rhamnose / Q000032:analysis; D017421:Sequence Analysis; D016339:Spectrometry, Mass, Fast Atom Bombardment; D014351:Trypanosomatina / Q000737:chemistry*
D006028:Glycosphingolipids; D017261:Glycosylphosphatidylinositols; D009844:Oligosaccharides; D012210:Rhamnose