Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1390482 | Carbohydrate Research | 2011 | 4 Pages |
Abstract
The structure of the O-antigen polysaccharide (PS) from Escherichia coli O177 has been determined. Component analysis together with 1H and 13C NMR spectroscopy experiments was used to determine the structure. Inter-residue correlations were determined by 1H,13C-heteronuclear multiple-bond correlation and 1H,1H-NOESY experiments. PS is composed of tetrasaccharide repeating units with the following structure:â2)-α-l-Rhap-(1â3)-α-l-FucpNAc-(1â3)-α-l-FucpNAc-(1â3)-β-d-GlcpNAc-(1âAn α-l-Rhap residue is suggested to be present at the terminal part of the polysaccharide, which on average is composed of â¼20 repeating units, since the 1H and 13C chemical shifts of an α-linked rhamnopyranosyl group could be assigned by a combination of 2D NMR spectra. Consequently, the biological repeating unit has a 3-substituted N-acetyl-d-glucosamine residue at its reducing end. The repeating unit of the E. coli O177 O-antigen shares the â3)-α-l-FucpNAc-(1â3)-β-d-GlcpNAc-(1â structural element with the O-antigen from E. coli O15 and this identity may then explain the reported cross-reactivity between the strains.
Related Topics
Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
Mona V. Svensson, Andrej Weintraub, Göran Widmalm,