aInstitute of Microbiology and Immunology, University of Lodz,
bN. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
KEYWORDS: Proteus mirabilis; O-polysaccharide; lipopolysaccharide; Na-(D-galacturonoyl)-L-lysine; serogroup
Eur. J. Biochem., 2002, v.269, pp.1406-1412
DOI: 10.1046/j.1432-1033.2002.02782.x (free full text)
The O-chain polysaccharide of the lipopolysaccharide (LPS) of a previously nonclassified strain of Proteus mirabilis termed G1 was studied by sugar analysis and 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, rotating-frame NOE (ROESY), H-detected 1H,13C heteronuclear multiple-quantum coherence (HMQC) and heteronuclear multiple-bond correlation (HMBC) experiments. The following structure of the polysaccharide was established:
where D-GalA6(L-Lys) stands for Na-(D-galacturonoyl)-L-lysine. The structure of the O-polysaccharide of P. mirabilis G1 is similar but not identical to that of P. mirabilis S1959 and OXK belonging to serogroup O3. Immunochemical studies with P. mirabilis G1 and S1959 anti-(O-polysaccharide) sera revealed close LPS-based serological relatedness of P. mirabilis G1 and S1959, and therefore it was suggested to classify P. mirabilis G1 in serogroup O3 as a subgroup. P. mirabilis G1 and S1959 anti-(O-polysaccharide) sera also cross-reacted with LPS of P. mirabilis strains from two other serogroups contain- ing D-GalA6(L-Lys) in the O-polysaccharide or in the core region.