aInstitute of Microbiology and Immunology, University of Lodz,
bN. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
KEYWORDS: Proteus penneri; O-antigen; O-specific polysaccharide; lipopolysaccharide; structure; ribitol phosphate, ethanolamine phosphate
Carbohydr. Res., 2002, v.337, pp.1535-1540
The O-specific polysaccharide the lipopolysaccharide of Proteus penneri strain 103 was studied using 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, NOESY, H-detected 1H,13C HMQC, H-detected 1H,31P HMQC and HMBC experiments. It was found that the polysaccharide is built up of oligosaccharide-ribitol phosphate repeating units and resembles thus ribitol teichoic acids of Gram-positive bacteria. The following structure of the polysaccharide was established:
PEtN |6 -3)bDGalpNAc(1-2)Rib-ol(1-P-4)bDGlcp(1-3)bDGalp(1-
where EtN and Rib-ol are ethanolamine and ribitol, respectively. This structure is unique among the known structures of Proteus O-antigens and, therefore, it was proposed to classify the strain studied into a new Proteus serogroup, O73. The molecular basis for cross-reactivity between O-antiserum against P. penneri 103 and O-antigens of P. mirabilis O33 and D52 is discussed.