Structure of Leishmania lipophosphoglycan: inter- and intra-specific polymorphism in Old World species.

Détails

ID Serval
serval:BIB_94DAE932F577
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Structure of Leishmania lipophosphoglycan: inter- and intra-specific polymorphism in Old World species.
Périodique
Biochemical Journal
Auteur(s)
McConville M.J., Schnur L.F., Jaffe C., Schneider P.
ISSN
0264-6021 (Print)
ISSN-L
0264-6021
Statut éditorial
Publié
Date de publication
1995
Volume
310 ( Pt 3)
Numéro
3
Pages
807-818
Langue
anglais
Notes
Publication types: Comparative Study ; Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Résumé
The most abundant surface macromolecule on the promastigote stage of leishmanial parasites is a polymorphic lipophosphoglycan (LPG). We have elucidated the structures of two new LPGs, from Leishmania tropica (LRC-L36) and L. aethiopica (LRC-L495), and investigated the nature of intra-specific polymorphism in the previously characterized LPG of L. major (LRC-L456 and -L580). These molecules contain a phosphoglycan chain, made up of repeating PO4-6Gal beta 1-4Man units and a conserved hexaglycosyl-phosphatidylinositol membrane anchor. Extensive polymorphism occurs in the extent to which the LPG repeat units are substituted with different glycan side chains. The L. tropica LPG is the most complex LPG characterized to date, as most of the repeat units are substituted with more than 19 different glycan side chains. All of these side chains, including the novel major glycans, Arap beta 1-3Glc beta 1- and +/- Arap beta 1-2Glc beta 1-4[+/- Arap beta 1-2]Glc beta 1-, are linked to the C-3 position of the backbone disaccharide galactose. In contrast, the L. aethiopica LPG repeat units are partially substituted (35%) with single alpha-mannose residues that are linked, unusually, to the C-2 position of the mannose in the backbone disaccharide. Polymorphism is also evident in the spectrum of alpha-mannose-containing oligosaccharides that cap the non-reducing terminus of the phosphoglycan chains of these LPGs. Finally, analysis of the L. major LPGs showed that, while some strains contain LPGs which are highly substituted with side chains of beta Gal, Gal beta 1-3Gal beta 1- and Arap beta 1-2Gal beta 1-3Gal beta 1-, the LPGs of other strains (i.e L. major LRC-L456) are essentially unsubstituted. Recent studies have shown that the LPG side chains and cap structures can mediate promastigote attachment to a number of different receptors along the midgut of the sandfly vector. The possible significance of LPG polymorphism on the ability of these parasites to infect a number of different sandfly vectors is discussed.
Mots-clé
Animals, Carbohydrate Conformation, Carbohydrate Sequence, Geography, Gerbillinae, Glycosphingolipids/chemistry, Glycosphingolipids/genetics, Glycosylphosphatidylinositols/chemistry, Glycosylphosphatidylinositols/isolation & purification, Humans, Leishmania/classification, Leishmania/genetics, Leishmania major/genetics, Leishmania tropica/genetics, Leishmaniasis, Cutaneous/parasitology, Molecular Conformation, Molecular Sequence Data, Oligosaccharides/chemistry, Oligosaccharides/isolation & purification, Polymorphism, Genetic, Skin/parasitology, Species Specificity, Spleen/parasitology
Pubmed
Web of science
Création de la notice
19/01/2008 18:30
Dernière modification de la notice
03/03/2018 19:38
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