title: Glycoinositol-phospholipid profiles of four serotypically distinct Old World Leishmania strains.
abstract: Glycoinositol-phospholipids (GIPLs) are the major glycolipid class and prominant surface antigens of leishmanial parasites. The GIPLs from four serologically distinct Old World strains of Leishmania were characterized to determine inter- and intra-specific differences in these glycolipids. These studies showed that: (1) the major GIPLs of Leishmania topica (LRC-L36) and Leishmania aethiopica (LRC-L495) belong to the alpha-mannose-terminating GIPL series (iM2, iM3 and iM4) that are structurally related to the glycosyl-phosphatidylinositol anchors of both the surface proteins and the abundant lipophosphoglycan (LPG). In contrast, the GIPLs from two Leishmania major strains (LRC-L456 and LRC-L580) belong to the alpha-galactose-terminating GIPL series (GIPL-1, -2 and -3) that are more structurally related to the LPG anchor; (2) the GIPL profiles of the L. major strains differed in that a significant proportion of the GIPL-2 and -3 species (approximately 40% and 80%, respectively) in LRC-L580 are substituted with a glucose-1-PO4 residue, while this type of substitution was not detected in LRC-L456; and (3) all the GIPLs contained either an alkylacyl- or a lysoalkyl-phosphatidylinositol lipid moiety. However, the alkyl chain compositions of different GIPLs within the same strain was variable. In L. major, the major GIPL species contained alkylacylglycerols with predominantly C18:0 and C24:0 alkyl chains, whereas the glucose-1-PO4-substituted GIPLs contained exclusively lysoalkylglycerols with C24:0 alkyl chains. In L. tropica, the major GIPL, iM2, contained predominantly C24:0 alkyl chains whereas the structurally related iM3 and iM4 GIPLs in this strain contained predominantly C18:0 alkyl chains. In L. aethiopica all the GIPLs (iM2, iM3, iM4) contained C18:0 alkyl chains. These data suggest that the synthesis of the GIPLs may occur in more than one subcellular compartment. The possibility that species-specific differences in the predominantly surface glycan structures may modulate the interaction of the parasite with the insect and mammalian hosts is discussed.
authors.affiliation: Department of Biochemistry, University of Dundee, U.K.
authors.forename: P
authors.initials: P
authors.lastname: Schneider
authors.forename: L F
authors.initials: LF
authors.lastname: Schnur
authors.forename: C L
authors.initials: CL
authors.lastname: Jaffe
authors.forename: M A
authors.initials: MA
authors.lastname: Ferguson
authors.forename: M J
authors.initials: MJ
authors.lastname: McConville
mesh_terms: D000818:Animals; D001894:Borohydrides; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D005690:Galactose / Q000032:analysis; D006017:Glycolipids / Q000032:analysis* / Q000737:chemistry; D006023:Glycoproteins / Q000737:chemistry; D017261:Glycosylphosphatidylinositols / Q000737:chemistry; D007891:Leishmania / Q000737:chemistry*; D018320:Leishmania major / Q000737:chemistry*; D007895:Leishmania tropica / Q000737:chemistry*; D008358:Mannose / Q000032:analysis; D008969:Molecular Sequence Data; D010743:Phospholipids / Q000032:analysis* / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry
chemical_list: D001894:Borohydrides; D006017:Glycolipids; D006023:Glycoproteins; D017261:Glycosylphosphatidylinositols; D010743:Phospholipids; D011134:Polysaccharides; C025364:sodium borohydride; D008358:Mannose; D005690:Galactose