The structure of the O-specific chain of Legionella pneumophila serogroup 1 lipopolysaccharide.

The O-polysaccharide chain of Legionella pneumophila Philadelphia strain 1 (serogroup 1) lipopolysaccharide was investigated by means of 1H- and 13C-NMR spectroscopy, and chemical analysis. It was found to consist of an alpha-(2-->4) interlinked homopolymer of a 5-acetamidino-7-acetamido-8-O-acetyl-3,5,7,9-tetradeoxy-nonulos onic acid possessing most likely the D-glycero-L-galacto configuration, representing the first example of an acidic homopolymer of a higher sugar of this class. The ladder-like banding pattern exhibiting small distances between individual bands in the SDS/PAGE is compatible with a monosaccharide repeating unit.