Change search
ReferencesLink to record
Permanent link

Direct link
Structural Elucidation of the O-Antigen Polysaccharide from Escherichia coli O181
Stockholm University, Faculty of Science, Department of Organic Chemistry.
Stockholm University, Faculty of Science, Department of Organic Chemistry.
2015 (English)In: ChemistryOpen, ISSN 2191-1363, Vol. 4, no 1, 47-55 p.Article in journal (Refereed) Published
Abstract [en]

Shiga-toxin-producing Escherichia coli (STEC) is an important pathogen associated to food-borne infection in humans; strains of E.coli O181, isolated from human cases of diarrhea, have been classified as belonging to this pathotype. Herein, the structure of the O-antigen polysaccharide (PS) from E.coli O181 has been investigated. The sugar analysis showed quinovosamine (QuiN), glucosamine (GlcN), galactosamine (GalN), and glucose (Glc) as major components. Analysis of the high-resolution mass spectrum of the oligosaccharide (OS), obtained by dephosphorylation of the O-deacetylated PS with aqueous 48% hydrofluoric acid, revealed a pentasaccharide composed of two QuiNAc, one GlcNAc, one GalNAc, and one Glc residue. The H-1 and (CNMR)-C-13 chemical shift assignments of the OS were carried out using 1D and 2D NMR experiments, and the OS was sequenced using a combination of tandem mass spectrometry (MS/MS) data and NMR (CNMR)-C-13 glycosylation shifts. The structure of the native PS was determined using NMR spectroscopy, and it consists of branched pentasaccharide repeating units joined by phosphodiester linkages: -> 4)[alpha-L-QuipNAc-(1 -> 3)]-alpha-D-GalpNAc6Ac-(1 -> 6)-alpha-D-Glcp-(1 -> P-4)-alpha-L-QuipNAc-(1 -> 3)-beta-D-GlcpNAc-(1 ->; the O-acetyl groups represent 0.4 equivalents per repeating unit. Both the OS and PSs exhibit rare conformational behavior since two of the five anomeric proton resonances could only be observed at an elevated temperature.

Place, publisher, year, edition, pages
2015. Vol. 4, no 1, 47-55 p.
Keyword [en]
Escherichia coli, NMR spectroscopy, O-antigen, polysaccharides, structure elucidation
National Category
Chemical Sciences
URN: urn:nbn:se:su:diva-116021DOI: 10.1002/open.201402068ISI: 000349953300007OAI: diva2:801781


Available from: 2015-04-10 Created: 2015-04-09 Last updated: 2015-12-04Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Widmalm, Göran
By organisation
Department of Organic Chemistry
In the same journal
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 15 hits
ReferencesLink to record
Permanent link

Direct link