RESUMEN
From Escherichia coli 0124 two lipopolysaccharide preparations were obtained with phenol/water extraction and cetavlon precipitation. Polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate and chemical analysis showed that the two preparations from E. coli 0124 and the corresponding preparations from Shigella dysenteriae type 3 reacted alike. The O-specific polysaccharide moiety was characterized with proton magnetic resonance spectroscopy, optical rotation and paper electrophoresis. The constituents were determined by gas chromatography and ion-exchange chromatography. The polysaccharide contained glucose (Glc), galactose (Gal), galactosamine (GalN) and 4-O-(1'-carboxyethyl)-D-glucopyranose (glucolactilic acid, GlcLA) in the molar ratios of 1:2:1:1. Glucolactilic acid, which has a structure similar to muramic acid, was first found in Sh. dysenteriae. The polysaccharide from E. coli 0124 and oligosaccharides obtained from it by partial acid hydrolysis were subjected to methylation analysis using the method of combined gas chromatography--mass spectrometry. The results indicated that the pentasaccharide repeating unit of the polysaccharide is (see article). In the polysaccharide the repeating units are joined through galactofuranosidic linkages. This structure is identical with that of the somatic polysaccharide of Sh. dysenterae type 3.
Asunto(s)
Pared Celular/análisis , Escherichia coli/análisis , Lipopolisacáridos , Polisacáridos Bacterianos , Shigella/análisis , Galactosamina/análisis , Galactosa/análisis , Glucosa/análisis , Pruebas de Hemaglutinación , Inmunodifusión , Lipopolisacáridos/aislamiento & purificación , Conformación Molecular , Oligosacáridos/análisis , Polisacáridos Bacterianos/aislamiento & purificación , Azúcares Ácidos/análisisAsunto(s)
Lipopolisacáridos , Polisacáridos Bacterianos , Shigella boydii/análisis , Shigella/análisis , Cromatografía de Gases , Cromatografía por Intercambio Iónico , Galactosa/análisis , Glucuronatos/análisis , Manosa/análisis , Metilación , Oxidación-Reducción , Ácido Peryódico , Especificidad de la EspecieRESUMEN
On mild acid hydrolysis of lipolysaccharide from Shigella dysenteriae type 3 the O-specific polysaccharide (hapten) was obtained which appeared to be acidic branched hexosaminoglycan. The repeating unit of this polysaccharide represents a pentasaccharide composed of two D-galactose residues, N-acetyl-D-galactosamine, D-glucose and unidentified acidic component. On the basis of methylation analysis, periodate oxidation, partial acid hydrolysis and chromic anhydride oxidation it is concluded that the structure of the chemical repeating unit of polysaccharide is (see article) where Glcp is glucopyranose, Galp is galactopyranose, Galf is galactofuranose, GalNAcp is 2-acetamido-2-deoxygalactopyranose and where the configuration of galactofuranoside glycosidic linkage and the structure of the acidic monosaccharide A are not known.