Carbohydrate recognition by enterohemorrhagic Escherichia coli: characterization of a novel glycosphingolipid from cat small intestine

Research output: Contribution to journalArticle

Abstract

A key virulence trait of pathogenic bacteria is the ability to bind to receptors on mucosal cells. Here the potential glycosphingolipid receptors of enterohemorrhagic Escherichia coli were examined by binding of S-35-labeled bacteria to glycosphingolipids on thin-layer chromatograms. Thereby a selective interaction with two nonacid glycosphingolipids of cat small intestinal epithelium was found. The binding-active glycosphingolipids were isolated and, on the basis of mass spectrometry, proton NMR spectroscopy, and degradation studies, identified as Galalpha3Galbeta4Glcbeta1Cer (isoglobotriaosylceramide) and Galalpha3Galalpha3Galbeta4Glcbeta1Cer. The latter glycosphingolipid has not been described before. The interaction was not based on terminal Galalpha3 because the bacteria did not recognize the structurally related glycosphingolipids Galalpha3Galalpha4Galbeta4Glcbeta1Cer and Galalpha3Galbeta4GlcNAcbeta3Galbeta4Glcbeta1Cer (B5 glycosphingolipid). However, further binding assays using reference glycosphingolipids showed that the enterohemorrhagic E. coli also bound to lactosylceramide with phytosphingosine and/or hydroxy fatty acids, suggesting that the minimal structural element recognized is a correctly presented lactosyl unit. Further binding of neolactotetraosylceramide, lactotetraosylceramide, the Le(a)-5 glycosphingolipid, as well as a weak binding to gangliotriaosylceramide and gangliotetraosylceramide, was found in analogy with binding patterns that previously have been described for other bacteria classified as lactosylceramide-binding.

Details

Authors
  • S Teneberg
  • J Angstrom
  • Åsa Ljungh
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Biochemistry and Molecular Biology

Keywords

  • enterohemorrhagic E. coli, carbohydrate binding, glycosphingolipids, mass spectrometry, microbial adhesion
Original languageEnglish
Pages (from-to)187-196
JournalGlycobiology
Volume14
Issue number2
Publication statusPublished - 2004
Publication categoryResearch
Peer-reviewedYes