title: Isolation and characterization of a novel Forssman active acidic glycosphingolipid with branched isoglobo-, ganglio-, and neolacto-series hybrid sugar chains.
abstract: Equine kidney and spleen contain a Forssman active glycosphingolipid, and the structure of this glycolipid has been reported to be that of a globopentaosylceramide (GalNAcalpha-1,3GalNAcbeta-1,3Galalpha-1, 4Galbeta-1,4Glcbeta-1,1'Ceramide). We found that equine kidney contains several other anti-Forssman antibody-reactive glycosphingolipids. One of these acidic Forssman active glycosphingolipids was isolated and characterized by means of NMR, mass spectrometry, permethylation studies, and TLC-immunostaining. This glycolipid contains three moles of galactose, one mole of glucose, three moles of N-acetylgalactosamine, one mole of N-acetylglucosamine, and one mole of N-acetylneuraminic acid, and is stained on TLC with anti-Forssman antibodies and anti-GM2 ganglioside antibodies. HOHAHA and ROESY experiments and permethylation studies showed this glycolipid oligosaccharide to be branched at the innermost galactose; one chain has an isoglobo structure with a terminal Forssman disaccharide and the other chain is branched through the linkage of N-acetylglucosaminebeta-1,6 to the inner galactose. The nonreducing end of the GM2 trisaccharide is linked to this glucosamine. The structure of the oligosaccharide of the glycolipid presented here is a novel type, having branched isoglobo-, ganglio-, and neolacto-series oligosaccharides. Mass spectrometric analyses indicated the ceramide moiety of the glycolipid to be composed predominantly of hydroxy fatty acids (C20:0, C22:0, C23:0, C24:0, and C25:0) and hydroxysphinganine. GalNAcalpha-1,3GalNAcbeta-1,3Galalpha-1,3[GalNAcbet a-1, 4(NeuAcalpha-2,3)Galbeta-1,4GlcNAcbeta-1,6]Galbeta+ ++-1,4Glcbeta-1, 1'Ceramide
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Yamamoto
authors.forename: N
authors.initials: N
authors.lastname: Iida-Tanaka
authors.forename: T
authors.initials: T
authors.lastname: Kasama
authors.forename: I
authors.initials: I
authors.lastname: Ishizuka
authors.forename: Y
authors.initials: Y
authors.lastname: Kushi
authors.forename: S
authors.initials: S
authors.lastname: Handa
mesh_terms: D000818:Animals; D002240:Carbohydrate Sequence; D002852:Chromatography, Ion Exchange; D002855:Chromatography, Thin Layer; D005915:Globosides / Q000737:chemistry*; D006736:Horses; D007668:Kidney / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008969:Molecular Sequence Data; D019158:N-Acetylneuraminic Acid / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D005915:Globosides; C010163:Forssman glycolipid; D019158:N-Acetylneuraminic Acid