Elzbieta Romanowska

Structural studies of the O-specific side-chains of the shigella sonnei phase I lipopolysaccharide

Abstract The structure of the O-specific side-chains of the Shigella sonnei phase I lipopolysaccharide has been investigated. The side chains are composed of disaccharide repeating-units containing two uncommon sugar components, one of witch, 2-amino-2-deoxy- L -altruronic acid, has been identified previously. The other has now been identified as 2-acetamido-4-amino-2,4,6-trideoxy- D -galactose. The uronic acid, as N-acetylated α-pyranosyl residues, is linked through O-4, and the diamino sugar, as β-pyranosyl residues, is linked through O-3. The pyranosyluronic acid residue assumes the 4C1 conformation in the polymer, with the carboxyl group in the axial position.

Basic structure of the oligosaccharide repeating-unit of the Shigella flexneri O-antigens

Abstract The Shigella flexneri O-antigens are composed of residues of l -rhamnose and 2-acetamido-2-deoxy- d -glucose (3:1), and their basic structure has been investigated. The O-antigen from Sh. flexneri variant Y was chosen for this study. Methylation analysis, n.m.r. spectroscopy, and analysis of the product of N -deacetylation-deamination were the principle methods used. These studies demonstrate that the O-antigen is composed of repeating units having the following structure: →3)-β- d -GlcNA cp -(1→2)-α- l -Rha p -(1→2)-α- l -Rha p -(1→3)-α- l -Rha p -(1→

Identification of a trisaccharide repeating-unit in the enterobacterial common-antigen

Abstract In addition to the previously reported 2-acetamido-2-deoxy- d -glucose and 2-acetamido-2-deoxy- d -mannuronic acid, 4-acetamido-4,6-dideoxy- d -galactose ( d -Fuc4NAc) is a major component of the enterobacterial common-antigen. The trisaccharide repeating-unit →4)-β- d -Man p NAcA-(1→4)-α- d -Glc p NAc-(1→3)- d -Fuc p 4NAc-(1→ constitutes 70% or more of this antigen.

The enterobacterial common-antigen, a cyclic polysaccharide.

Structural studies of the enterobacterial common-antigen, using chemical methods and fast-atom-bombardment mass spectrometry, indicate that it is a cyclic polysaccharide, composed of four, five, and, to a smaller extent, six trisaccharide repeating-units. In the structure of the antigen, given below, D-Fuc4NAc stands for 4-acetamido-4,6-dideoxy-D-galactose.

The structure of the sialic acid-containing Escherichia coli O104 O-specific polysaccharide and its linkage to the core region in lipopolysaccharide

Mild acid hydrolysis of Escherichia coli O104 lipopolysaccharide released an O-specific polysaccharide, a tetrasaccharide repeating unit, the corresponding dimer, and a disaccharide fragment of the repeating unit. Complete and incomplete cores, and oligosaccharides comprising fragments of the repeating unit and the core region, were also obtained. On the basis of sugar and methylation analysis, FAB-mass spectrometry and NMR spectroscopy of the hydrolysis products, the repeating unit of the O-specific polysaccharide was shown to be the tetrasaccharide:-->4)-alpha-D-Galp-(1-->4)-alpha-Neup5,7,9Ac3++ +-(2-->3)-beta-D- Galp-(1-->3)-beta-D-GalpNAc (1-->. The linkage between the O-specific polysaccharide chain and the core region, which appeared to be of the R2 type, was established. These results indicate that N-acetylneuraminic acid, located in the O-specific polysaccharide, is an inherent lipopolysaccharide component.

The structure of glycerol teichoic acid-like O-specific polysaccharide of Hafnia alvei 1205

The O-specific polysaccharide of Hafnia alvei 1205 contained D-glucose, D-galactose, 2-acetamido-2-deoxy-D-glucose, 4-acetamido-4,6-dideoxy-D-glucose (Qui4NAc), glycerol, phosphate, and O-acetyl groups. On the basis of 1D and 2D shift-correlated homonuclear and 13C-1H heteronuclear NMR spectroscopy, methylation analysis, Smith degradation, and dephosphorylation with hydrofluoric acid, it was concluded that the O-antigen was a partially O-acetylated teichoic acid-like polysaccharide having the following structure: [formula: see text]

Structure of the O-specific polysaccharide of Hafnia alvei 1204 containing 3,6-dideoxy-3-formamido-D-glucose.

The O-specific polysaccharide of Hafnia alvei strain 1204 has a hexasaccharide repeating unit containing D-mannose, D-glucuronic acid, 2-acetamido-2-deoxy-D-glucose, 2-acetamido-2-deoxy-D-galactose, and 3,6-dideoxy-3-formamido-D-glucose (Qui3NFo) in the ratios 2:1:1:1:1 as well as O-acetyl groups. On the basis of methylation analysis of the intact, carboxyl-reduced, and Smith-degraded polysaccharide as well as 1D and 2D NMR spectroscopy, including 1D total correlation spectroscopy, 1D NOE spectroscopy, 2D homonuclear shift-correlated spectroscopy (COSY), and 13C,1H heteronuclear COSY, the following structure of the O-deacetylated polysaccharide was established: -->3)-alpha-D-Manp-(1-->2)-alpha-D-Manp-(1-->3)-beta-D-GlcpN Ac-(1--> -->2)-beta-D-Quip3NFo-(1-->3)-alpha-D-GalpNAc-(1-->4)-alpha-D-G lcpA-(1--> Location of the N-formyl group, occurring as two stereoisomers in the ratio approximately 3:1, was determined by an NOE on H-3 Qui3N arising on pre-irradiation of HCO of the minor (E) isomer. The O-acetyl groups are attached in nonstoichiometric amounts at position 3 of GlcA and position 6 of a mannose residue or GlcNAc.

Structure elucidation of the core octasaccharide from Citrobacter PCM 1487 with the aid of 500-MHz, two-dimensional phase-sensitive correlated, relayed-coherence transfer, double-quantum, triple-quantum filtered, and N.O.E. 1H-n.m.r. spectra

Abstract The main features of the primary structure of the octasaccharide, α- d -Glc p -(1→2)-α- d -Glc p -(1→2)-[α- d -Gal p NAc- (1→3)]-α- d -Gal p -(1→3)-α- d -Glc p -(1→3)-[α- ld -Hep p -(1→7)]-α- ld -Hep p -(1→3)-α- ld -Hep, have been determined in the ab initio manner by 1 H-n.m.r. spectroscopy without resorting to biochemical methods of analysis. Several nontypical interresidue n.O.e. values point to a preferred solution conformation of the molecule.

Lipopolysaccharide core region of Hafnia alvei: structure elucidation using chemical methods, gas chromatography−mass spectrometry, and NMR spectroscopy

Sugar and methylation analysis with the use of gas chromatography-mass spectrometry and 1H NMR spectroscopy proved that the core oligosaccharides isolated from lipopolysaccharides of eight Hafnia alvei strains have the identical hexasaccharide skeleton. However, 1H, 31P heterocorrelated spectra showed that the phosphorylation pattern is not the same. The branched heptose for the ATCC 13337, 1187, 2, 1191, 1196, 1220, and 481L strains is phosphorylated as in the following formula, where P = -O-P(O)(O-)2 and P-PEtN = [-O-P(O)(O-)]2-O(CH2)2NH3+ [formula: see text] A different phosphorylation pattern was found for the 1211 strain, where the branched heptose residue is 6-substituted by a monophosphorylethanolamine group, ...-->3(-->7)(PEtN-->6)-alpha-LD-Hepp-(1-->3)..., where PEtN = -O-P(O)(O-)-O(CH2)2NH3+.

The structure of the O-specific polysaccharide from Hafnia alvei strain 38 lipopolysaccharide

The O-specific polysaccharide of the lipopolysaccharide from H. alvei strain 38 has been established by NMR spectroscopy (13C and 1H) and methylation analysis to have the repeating unit-->4)-beta-D-ManpNAc-(1-->4)-alpha-D-GlcpNAc(1-->.