Structure of the lipid moiety of the Leishmania donovani lipophosphoglycan.
The lipid moiety of the lipophosphoglycan of Leishmania donovani had been isolated and characterized as a novel lyso-alkylphosphatidylinositol. Treatment of lipophosphoglycan with either 10% NH4OH or a phosphatidylinositol-specific phospholipase C from Staphylococcus aureus liberated a monoalkylglycerol substituent. Structural characterization of the monoalkylglycerol by gas-liquid chromatography-mass spectrometry indicated the presence of two saturated, unbranched hydrocarbons: a C24 alkyl chain comprising 78% of the lipid with the remaining 22% as a C26 alkyl chain. Periodate sensitivity demonstrated that the alkyl side chain is linked to the C-1 position of the glycerol backbone. Treatment of lipophosphoglycan with nitrous acid released 1-O-alkylglycerophosphorylinositol due to an unacetylated glucosamine residue linked to the inositol of the lyso-alkylphosphatidylinositol. Quantitative analysis of the organic solvent-soluble product of nitrous acid deamination of lipophosphoglycan confirmed the expected ratio of inositol:phosphate:1-O-alkylglycerol as 1:1:1. These results suggest that L. donovani anchors its lipophosphoglycan with a unique lipid component.
D000818:Animals; D002855:Chromatography, Thin Layer; D008401:Gas Chromatography-Mass Spectrometry; D006028:Glycosphingolipids / Q000032:analysis*; D007294:Inositol / Q000378:metabolism; D007893:Leishmania donovani / Q000032:analysis*; D008055:Lipids / Q000032:analysis; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism
D006028:Glycosphingolipids; D008055:Lipids; D010169:Palmitic Acids; C008290:lipophosphonoglycan; D019308:Palmitic Acid; D007294:Inositol