ABSTRACT
Three different oligosaccharide structures from the lipooligosaccharide fraction of Agrobacterium tumefaciens strain A1 were determined by means of chemical and spectrometrical methods. The peculiar feature of this oligosaccharide family consisted of its unusual length, that was very close to the that minimal requested for the external membrane functionality as exemplified from oligosaccharide 3, where the inner core is glycosylated from only one sugar moiety onwards.
Subject(s)
Agrobacterium tumefaciens , Lipopolysaccharides/chemistry , Oligosaccharides/chemistry , Carbohydrate Sequence , Magnetic Resonance Spectroscopy , Molecular Sequence Data , Molecular Structure , Oligosaccharides/isolation & purificationABSTRACT
Agrobacterium tumefaciens F/1 produces two different O-chains, both are constituted of rhamnose and glucosamine: the less abundant has a linear disaccharidic repeating unit 3)-alpha-L-Rhap-(1-->3)-beta-D-GlcpNAc-(1--> and the second one 4)-alpha-L-Rhap-(1-->3)-beta-D-GlcpNAc-(1-->. The two intact antigenic moieties were studied in mixture by 2D NMR. Additional supporting data were obtained by periodate degradation, the major component was cleaved selectively, leading to a glucosamine glycoside, whereas the minor one was recovered unaffected.
Subject(s)
Agrobacterium tumefaciens/metabolism , O Antigens/chemistry , Carbohydrate Sequence , Molecular Sequence Data , Molecular Structure , O Antigens/biosynthesis , Periodic Acid/chemistryABSTRACT
A linear homopolysaccharide built of 3-alpha-L-6dTalp residues, randomly acetylated at position C-4, is described for the O-specific polysaccharide of Agrobacterium tumefaciens strain C58. This structure, determined by spectroscopical and chemical methods, is strictly correlated to that of Rhizobium loti strain NZP2213, which differs for the degree and the position of O-acetylation.
Subject(s)
Agrobacterium tumefaciens/chemistry , Deoxy Sugars/analysis , Hexoses/analysis , Lipopolysaccharides/chemistry , O Antigens/chemistry , Acetates/chemistry , Acetylation , Carbohydrate Sequence , Electrophoresis, Polyacrylamide Gel , Gas Chromatography-Mass Spectrometry , Hydrolysis , Lipopolysaccharides/isolation & purification , Magnetic Resonance Spectroscopy , Molecular Sequence Data , O Antigens/isolation & purification , Polysaccharides, Bacterial/chemistryABSTRACT
An O-specific polysaccharide containing D-galactose and D-glucose, was isolated from the water-soluble lipopolysaccharide fraction of the alkaliphilic bacterium Halomonas magadii. The structure, determined by means of chemical analysis and 1D and 2D NMR spectroscopy, showed a trisaccharide repeating unit, as shown below: [structure: see text]
