Structural determination of the O-antigenic polysaccharide of enteropathogenic Escherichia coli O103:H2

The structure of the antigenic O-polysaccharide isolated from the lipopolysaccharide produced by enterohemorrhagic Escherichia coli O103:H2 was determined and shown to be composed of D-glucose (1 part), 2-acetamido-2-deoxy-Dglucose (2 parts), 2-acetamido-2-deoxy-D-galactose (1 part), and 3-deoxy-3-(R)-3-hydroxybutyramido-D-fucose (1 part). From the results of methylation analysis, Smith-type periodate oxidation degradation studies, and the use of one- and twodimensional 1H and 13C NMR spectroscopy, the O-polysaccharide antigen was found to be an unbranched polymer of a repeating pentasaccharide unit having the following structure: ->2)-b-D-Glcp-(1->2)-b-D-Fucp3NBu-(1->6)-a-D-GlcpNAc- (1->4)-a-D-GalpNAc-(1->3)-b-D-GlcpNAc-(1->, where Bu is (R)-3-hydroxybutyramido.La structure du polysaccharide d\u2019antig\ue8ne O isol\ue9 du lipopolysaccharide produit par Escherichia coli O103:H2 ent\ue9ro-h\ue9morragique a \ue9t\ue9 d\ue9termin\ue9e et s\u2019est av\ue9r\ue9e compos\ue9e de D-glucose (1 partie), de 2-ac\ue9tamido-2-d\ue9oxy-D-glucose (2 parties), de 2-ac\ue9tamido-2-d\ue9oxy-D-galactose (1 partie) et de 3-d\ue9oxy-3-(R)-3-hydroxybutyramido-D-fucose (1 partie). Selon les r\ue9sultats d\u2019analyses de m\ue9thylation, d\u2019\ue9tudes de d\ue9gradation par l\u2019oxydation au periodate de Smith et de l\u2019utilisation de la spectroscopie 1H et 13C unidimensionnel et bidimensionnel, le polysaccharide O est apparu comme un polym\ue8re non branch\ue9 d\u2019unit\ue9s pentasaccharides r\ue9p\ue9t\ue9es poss\ue9dant la structure suivante: ->2)-b-D-Glcp-(1->2)-b-DFucp3NBu-( 1->6)-a-D-GlcpNAc-(1->4)-a-D-GalpNAc-(1->3)-b-D-GlcpNAc-(1->, o\uf9 Bu est le (R)-3-hydroxybutyramido.Peer reviewed: YesNRC publication: Ye