New Structures of the O-Specific Polysaccharides of Bacteria of the Genus Proteus. 1. Phosphate-Containing Polysaccharides

F. V. Toukach¹, A. N. Kondakova¹, N. P. Arbatsky¹, S. N. Senchenkova¹, A. S. Shashkov¹, Y. A. Knirel^1*, K. Zych², A. Rozalski², and Z. Sidorczyk²

¹Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninskii pr. 47, Moscow, 119991 Russia; fax: (095) 135-5328; E-mail: knirel@ioc.ac.ru

²Institute of Microbiology and Immunology, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland; fax: (48-42) 678-4932; E-mail: zsidor@biol.uni.lodz.pl

^* To whom correspondence should be addressed.

Received March 23, 2001

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The O-specific polysaccharide chains (O-antigens) of the lipopolysaccharides of five Proteus strains, P. vulgaris O17, P. mirabilis O16 and O33, and P. penneri 31and 103, were found to contain phosphate groups that link the non sugar components, e.g., ethanolamine and ribitol. The polysaccharides of P. mirabilis O16 and P. penneri 103 include ribitol phosphate in the main chain and thus resemble ribitol teichoic acids of Gram-positive bacteria. The structures of the polysaccharides were elucidated using NMR spectroscopy, including two-dimensional ¹H,¹H correlation spectroscopy (COSY and TOCSY), nuclear Overhauser effect spectroscopy (NOESY or ROESY), and H-detected ¹H,¹³C and ¹H,³¹P heteronuclear multiple-quantum coherence spectroscopy (HMQC), along with chemical methods. The structures determined are unique among the bacterial polysaccharides and, together with the data obtained earlier, represent the chemical basic for classification of Proteus strains. Based on structural similarities of the O-specific polysaccharides and serological relationships between the O-antigens, we propose to extend Proteus serogroups O17 and O19 by including P. penneri strains 16 and 31,respectively.

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KEY WORDS: lipopolysaccharide, O-specific polysaccharide, O-antigen, bacterial polysaccharide structure, ethanolamine phosphate, ribitol phosphate, Proteus, NMR spectroscopy

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