aN. D. Zelinsky Institute of Organic Chemistry, Russian Academy
of Sciences, Moscow, Russia,
bInstitute of Microbiology and Immunology, University of Lodz, Poland
KEYWORDS: Proteus penneri, O-antigen, O-serogroup, 2-aminoethyl phosphate, lipopolysaccharide, structure
Eur. J. Biochem., 2000, v. 267, pp.601-605
DOI: 10.1046/j.1432-1327.2000.01041.x (free full text)
The lipopolysaccharide of Proteus penneri strain 63 was degraded by mild acid to give a high-molecular-mass O-specific polysaccharide isolated by gel-permeation chromatography. Sugar and methylation analyses and NMR spectroscopic studies, including 2D 1H, 1H COSY, TOCSY, rotating-frame NOE spectroscopy (ROESY), H-detected 1H,13C and 1H,31P heteronuclear multiple-quantum coherence (HMQC), and 1H,13C HMQC-TOCSY experiments, demonstrated the following structure of the polysaccharide:
bDGlcp PEtN |4 |6 -6)aDGlcpNAc(1-3)aLFucpNAc(1-3)bDGlcpNAc(1-2)bDGlcp(1-
where FucNAc is 2-acetamido-2,6-dideoxygalactose and PEtN is 2-aminoethyl phosphate.
The polysaccharide studied shares some structural features, such as the presence of bDGlcNAc6PEtn and aLFucNAc(1-3)bDGlcNAc fragments, with other Proteus O-specific polysaccharides. A marked cross-reactivity of P. penneri 63 O-antiserum with Proteus vulgaris O12 was observed and substantiated by a structural similarity of the O-specific polysaccharides of two strains. In spite of this, the P. penneri 63 polysaccharide has the unique structure among Proteus O-antigens, and, therefore, a new, separate serogroup O68 is proposed for this strain.