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; O-serogroup; lipopolysaccharide
Eur. J. Biochem., 2002, v.269, pp.358-363
DOI: 10.1046/j.0014-2956.2001.02660.x (free full text)
O-specific polysaccharides (O-antigens) of Proteus penneri strains 1 and 4 were studied using sugar analysis, 1H and 13C NMR spectroscopy, including two-dimensional COSY, H-detected 1H,13C heteronuclear multiple-quantum coherence (HMQC), and rotating-frame NOE spectroscopy (ROESY). The following structures of their tetrasaccharide (strain 1) and pentasaccharide (strain 4) repeating units were established:
bDGalpNAc |3 -4)aDGalp(1-6)bDGlcpNAc(1-3)bDGalpNAc(1- aDGlcp bDGalpNAc |6 |3 -6)bDGlcp(1-3)bDGalpNAc-(1-4)aDGalp(1-
In the polysaccharide of P. penneri strain 4, glycosylation with the lateral Glc residue (75%) and O-acetylation of the lateral GalNAc residue (55%) are nonstoichiometric. This polysaccharide contains also other, minor O-acetyl groups, whose positions were not determined. The structural similarity of the O-specific polysaccharides was consistent with the close serological relatedness of the LPS, which was demonstrated by immunochemical studies with O-antisera against P. penneri 1 and 4. Based on these data, it was proposed to classify P. penneri strains 1 and 4 into a new Proteus serogroup, O72, as two subgroups, O72a and O72b, respectively. Serological cross-reactivity of P. penneri 1 O-antiserum with the LPS of P. penneri 40 and 41 was substantiated by the presence of an epitope(s) on the LPS core region shared by all P. penneri strains studied.