Structures of the O-antigens of Escherichia coli O13, O129, and O135 related to the O-antigens of Shigella flexneri

• Published in: Carbohydrate research 2010-07, Vol.345 (11), p.1594-1599
• Main Authors: Perepelov, Andrei V., Shevelev, Sergei D., Liu, Bin, Senchenkova, Sof’ya N., Shashkov, Alexander S., Feng, Lu, Knirel, Yuriy A., Wang, Lei
• Format: Article
• Language: English
• Subjects: Acetylation; Bacterial polysaccharide structure; Carbohydrate Sequence; Escherichia coli; Escherichia coli - chemistry; Escherichia coli - classification; Glucosylation site; Magnetic Resonance Spectroscopy; Molecular Sequence Data; O Antigens - chemistry; O-Acetylation; O-Antigen; Oxygen - chemistry; Shigella flexneri; Shigella flexneri - chemistry
• ISSN: 0008-6215; 1873-426X
• DOI: 10.1016/j.carres.2010.04.023

O-Polysaccharides (O-antigens) were isolated from Escherichia coli O13, O129, and O135 and studied by chemical analyses along with 2D 1H and 13C NMR spectroscopy. They were found to possess a common →2)- l-Rha-(α1→2)- l-Rha-(α1→3)- l-Rha-(α1→3)- d-GlcNAc-(β1→ backbone, which is a characteristic structural motif of the O-polysaccharides of Shigella flexneri types 1–5. In both the bacterial species, the backbone is decorated with lateral glucose residues or/and O-acetyl groups. In E. coli O13, a new site of glycosylation on 3-substituted Rha was revealed and the following O-polysaccharide structure was established: ▪ The structure of the E. coli O129 antigen was found to be identical to the O-antigen structure of S. flexneri type 5a specified in this work and that of E. coli O135 to S. flexneri type 4b reported earlier.