Structure of the O-Specific Polysaccharide of the Bacterium Proteus vulgaris O23

A. V. Perepelov¹, A. S. Shashkov¹, D. Babichka², S. N. Senchenkova¹, B. Bartodziejska², A. Rozalski², and Y. A. Knirel^1*

¹Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky pr. 47, Moscow, 117913 Russia; fax: (095) 135-5328; E-mail: knirel@ioc.ac.ru

²Department of Immunobiology of Bacteria, Institute of Microbiology and Immunology, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland

^* To whom correspondence should be addressed.

Received January 11, 2000

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An acidic O-specific polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of the bacterium Proteus vulgaris O23 (strain PrK 44/57) and found to contain 2-acetamido-2-deoxy-D-galactose, 2-acetamido-2-deoxy-D-glucose, and D-galacturonic acid. Based on ¹H- and ¹³C-NMR spectroscopic studies, including two-dimensional correlation spectroscopy (COSY), total correlation spectroscopy (TOCSY), nuclear Overhauser effect spectroscopy (NOESY), and ¹H,¹³C heteronuclear multiple-quantum coherence (HMQC) experiments, the following structure of the branched tetrasaccharide repeating unit of the polysaccharide was established: [figure], where the degree of O-acetylation of the terminal GalA residue at position 4 is about 80%. A structural similarity of the O-specific polysaccharides of P. vulgaris O23 and P. mirabilis O23 is discussed.

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KEY WORDS: O-antigen, lipopolysaccharide, bacterial polysaccharide, structure, Proteus vulgaris

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