The characterization of the O-antigen of Escherichia coli 064:K99 lipopolysaccharide.

The structure of the O-polysaccharide of the smooth lipopolysaccharide (LPS) produced by Escherichia coli O64:K99 was investigated by SDS-PAGE, composition, periodate oxidation, methylation, partial hydrolysis, and 1D and 2D nuclear magnetic resonance analyses, made on the native o-chain and its reduction and periodate degradation products. The E. coli O64 antigenic O-chain was found to be a high molecular weight glycan composed of D-galactose, D-glucuronic acid, 2-acetamido-2-deoxy-D-glucose, and 2-acetamido-2-deoxy-D-mannose (2:1:1:1) and was a polymer of branched pentasaccharide repeating units having the structure: [formula: see text]