title: Neu5Acalpha3Gal is part of the Helicobacter pylori binding epitope in polyglycosylceramides of human erythrocytes.
abstract: The sialic acid dependent binding by the human pathogen Helicobacter pylori to polyglycosylceramides of human erythrocytes was investigated. Polyglycosylceramides, complex glycosphingolipids with a branched N-acetyllactosamine core, were isolated from human erythrocytes, blood group O, and subfractionated after peracetylation by anion-exchange chromatography. Three subfractions were deacetylated, analysed by matrix-assisted laser desorption ionization-time of flight MS and 2D 1H NMR spectroscopy. The observed mass ranges were m/z = 3093-7622, 3968-7255 and 3459-7987 in the mass spectra of the first, second and third fractions, respectively. The observed ions agreed with the general formula Hex(x+2)HexNAcxFucyNeu5AczCer. Two-dimensional 1H total correlation spectra of the mixtures showed that the first fraction contained 3-linked sialic acid and the second and third fractions contained both 3-linked and 6-linked sialic acid. Thin-layer chromatogram binding assays using the lectins from Maackia amurensis, specific for Neu5Acalpha3Galbeta4GlcNAc, and Sambucus nigra, specific for Neu5Acalpha6Gal/GalNAc, were used to confirm this distribution. H. pylori recognized all three fractions in the binding assay, indicating that the 3-linked, rather than 6-linked, sialic acid is essential for binding.
authors.affiliation: Institute of Medical Biochemistry, Göteborg University, Sweden.
authors.forename: L
authors.initials: L
authors.lastname: Johansson
authors.forename: P
authors.initials: P
authors.lastname: Johansson
authors.forename: H
authors.initials: H
authors.lastname: Miller-Podraza
mesh_terms: D002518:Ceramides / Q000737:chemistry / Q000378:metabolism; D002852:Chromatography, Ion Exchange; D002855:Chromatography, Thin Layer; D004187:Disaccharides / Q000737:chemistry*; D000939:Epitopes; D004912:Erythrocytes / Q000382:microbiology*; D005915:Globosides / Q000737:chemistry; D016480:Helicobacter pylori / Q000378:metabolism*; D006601:Hexoses / Q000737:chemistry; D006801:Humans; D037102:Lectins / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D019158:N-Acetylneuraminic Acid / Q000737:chemistry; D011485:Protein Binding; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D002518:Ceramides; D004187:Disaccharides; D000939:Epitopes; D005915:Globosides; D006601:Hexoses; D037102:Lectins; D019158:N-Acetylneuraminic Acid