title: Structure of the core part of the lipopolysaccharides from Proteus penneri strains 7, 8, 14, 15, and 21.
abstract: The core-lipid A region of the lipopolysaccharides from Proteus penneri strains 7, 8, 14, 15, and 21 was studied using NMR spectroscopy, ESI MS, and chemical analysis after alkaline deacylation, deamination, and mild-acid hydrolysis of the lipopolysaccharides. The following general structure of the major core oligosaccharides is proposed: [abstract: see text] where all sugars are in the pyranose form and have the D configuration unless otherwise stated, Hep and DDHep=L-glycero- and D-glycero-D-manno-heptose, respectively, K=H, and Q=H in strain 8 or alpha-Glc in strains 7, 14, 15, and 21. In addition, several minor structural variants are present, including those lacking Ara4N in strains 7 and 15 and having the alpha-GlcN residue N-acylated to a various degree with glycine in strains 7, 8, 14, and 21. In strain 14, there are also core oligosaccharides with K=amide of beta-D-GalpA with putrescine, spermidine, or 4-azaheptane-1,7-diamine; remarkably, these structural variants lack either the PEtN group or the alpha-Hep-(1-->2)-alpha-DDHep disaccharide fragment at alpha-D-GalpA. While structural features of the inner core part are shared by Proteus strains studied earlier, the outermost Q-(1-->4)-alpha-GalNAc-(1-->2)-alpha-DDHep-(1-->6)-alpha-GlcN oligosaccharide unit has not been hitherto reported.
authors.affiliation: Institute for Biological Sciences, National Research Council, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada. evguenii.vinogradov@nrc.ca
authors.forename: Evgeny
authors.initials: E
authors.lastname: Vinogradov
authors.forename: Zygmunt
authors.initials: Z
authors.lastname: Sidorczyk
authors.forename: Yuriy A
authors.initials: YA
authors.lastname: Knirel
mesh_terms: D002236:Carbohydrate Conformation; D008070:Lipopolysaccharides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D009844:Oligosaccharides / Q000737:chemistry*; D011511:Proteus / Q000737:chemistry*; D011700:Putrescine / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D013095:Spermidine / Q000737:chemistry
chemical_list: D008070:Lipopolysaccharides; D009844:Oligosaccharides; C430212:lipopolysaccharide, Proteus; D013095:Spermidine; D011700:Putrescine