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1.
Braz. j. med. biol. res ; 27(2): 239-42, Feb. 1994. ilus
Article Dans Anglais | LILACS | ID: lil-140258

Résumé

Two glycoinositol phospholipids (GIPL A and GIPL B) have been purified from epimastigotes of Trypanosoma cruzi at the logarithmic phase of growth (2 days). The GIPLs differ mainly in the lipid moiety and are similar to the lipopeptidophosphoglycan (LPPG) previously isolated from epimastigotes at the stationary phase (4-5 days). [3H]-palmitic acid was incorporated into 1-O-hexadecyl-2-O-palmitoylglycerol in GIPL A and into a sphinganine ceramide with palmitic acid and lignoceric acid as the fatty acids in GIPL B. The lipids could be released by incubation with phosphatidylinositol-specific phospholipase C (PI-PLC) or glycosylphosphatidylinositol phospholipase D (GPI-PLD) from rat serum. The oligosaccharides share the common core structure of the glycosylphosphatidilinositol (GPI) membrane anchors. Microheterogeneity was demonstrated, as well as substitution by galactose, which is mainly in the furanose configuration as was previously described for the LPPG. However, methylation analysis indicated that 20 percent of the galactose is present as terminal pyranose units. In infective trypomastigotes, [3H]-palmitic acid was incorporated into the anchor of the Tc-85 glycoprotein. The lipid cleaved by phospholipase C digestion was identified as 1-O-hexadecylglycerol and the main oligosaccharide has the structure of the conserved core of all GPI anchors. [3H]-palmitic acid-labelled Tc-85 released into the culture medium as membrane vesicles showed 80 percent resistance to the action of PI-PLC. However, after mild alkaline hydrolysis, part of the radioactivity was released by the enzyme


Sujets)
Animaux , Rats , Glycosphingolipides/composition chimique , Oligosaccharides/composition chimique , Trypanosoma cruzi/composition chimique , Séquence glucidique , Acides gras , Glycosphingolipides/isolement et purification , Données de séquences moléculaires , Oligosaccharides/analyse , Oligosaccharides/isolement et purification , Acides palmitiques , Peptidoglycane/composition chimique , Peptidoglycane/isolement et purification , Phospholipides/composition chimique , Phospholipides/isolement et purification , Type C Phospholipases
2.
Ciênc. cult. (Säo Paulo) ; 43(1): 69-72, Jan.-Feb. 1991. tab, ilus
Article Dans Anglais | LILACS | ID: lil-113452

Résumé

The lipopeptidophosphoglycan (LPPG) component isolated from epimastigote forms of Trypanosoma cruzi has antigenic properties. Using a rabbit antiserum aginst LPPG, specific for ß-D-galactofuranosyl residues (1-3)-linked to alfa-Dmannopyranose, we identified, by indirect immunofluorescence, the presence of epitopes containing ß-D-galactofuranosyl structures on the cell membrane of epimastigote, amastigote and trypomastigote forms of the parasite. The results demonstrade that all developmental stages of T. cruzi contain similar antigenic determinants on their cell body and flagellar membrane


Sujets)
Animaux , Lapins , Glycoconjugués/isolement et purification , Peptidoglycane/isolement et purification , Phospholipides/isolement et purification , Trypanosoma cruzi/croissance et développement , Antigènes de protozoaire/isolement et purification , Antigènes de surface/isolement et purification , Épitopes , Technique d'immunofluorescence , Glycoconjugués/composition chimique , Peptidoglycane/composition chimique , Phospholipides/composition chimique , Trypanosoma cruzi/immunologie
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