Structural analysis of inositol phospholipids from Trypanosoma cruzi epimastigote forms.
Inositol phospholipids (IPL) from epimastigote forms of Trypanosoma cruzi have been investigated by metabolic labelling with [3H]palmitic acid and by GLC-MS analysis of the lipids obtained from non-labelled parasites. The IPL fraction was separated into phosphatidylinositol (PI) and inositol-phosphoceramide subfractions, the latter accounting for 80-85% of the total IPL. The neutral lipids released from the IPLs by PI-specific phospholipase C (PI-PLC) from Bacillus thuringiensis were analysed by silica-gel and reverse-phase TLC for the radioactive lipids and by GLC-MS for the non-radioactive samples. Ceramides containing dihydrosphingosine and sphingosine with C16:0 and C18:0 fatty acids were identified. The main component in the [3H]palmitic acid-labelled ceramides was palmitoyldihydrospingosine, while in the non-labelled sample the ceramides contained mainly sphingosine. This could reflect partial uptake of phospholipid from the medium. The PI contain both alkylacyl- and diacyl-glycerol lipids, with the ether lipid being more abundant. The latter was identified as 1-O-hexadecylglycerol esterified by C18:2 and C18:1 fatty acids. Interestingly, the same lipid had been identified in the anchor of the 1G7 glycoprotein of T. cruzi metacyclic forms.
Bertello
L E
LE
Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina.
Gonçalvez
M F
MF
Colli
W
W
de Lederkremer
R M
RM
D000818:Animals; D001413:Bacillus thuringiensis / Q000201:enzymology; D002240:Carbohydrate Sequence; D002855:Chromatography, Thin Layer; D008401:Gas Chromatography-Mass Spectrometry; D008969:Molecular Sequence Data; D015394:Molecular Structure; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D010716:Phosphatidylinositols / Q000737:chemistry* / Q000302:isolation & purification; D054801:Phosphoinositide Phospholipase C; D010727:Phosphoric Diester Hydrolases / Q000737:chemistry; D014349:Trypanosoma cruzi / Q000737:chemistry*
D010716:Phosphatidylinositols; D010727:Phosphoric Diester Hydrolases; D054801:Phosphoinositide Phospholipase C; D043265:Phosphatidylinositol Diacylglycerol-Lyase