Somatic Antigens of Shigella

Abstract

The O-specific polysaccharide obtained from the lipopolysaccharide of Shigella dysenteriae type 1 (Shigella shiga) by mild acid hydrolysis followed by fractionation on Sephadex G-50 was found to be identical to that described by Morgan's group and was composed of L-rhamnose, D-galactose and N-acetyl-D-glucosamine in a ratio 2 : 1 : 1. On the basis of methylation analysis data the polysaccharide was proved to be a linear chain of monosaccharide residues in pyranose forms substituted at position 3, except for that of galactose substituted at position 2.Selective cleavage, based on the N-deacetylation reaction of the polymer, together with determination of linkage configurations by chromic anhydride oxidation showed that the O-specific polysaccharide is built up of repeating tetrasaccharide units whose proposed structure is given belowwhere Rhap = rhamnopyranose, Galp = galactopyranose, and GlcNAcp = N-acetyl-glucosamine.The present findings confirmed the considerations of Heidelberger on the substitution patterns of L-rhamnose and D-galactose residues from the results of serological studies.Sliigella dysenteriae type 1 (Sh. shigu) is the most investigated from ten serotypes of Slzigella dysenteriae subgroup and its O-specific polysaccharide was found to be composed of L-rhamnose, D-galactose and N-acetyl-D-glucosamine residues [l, 21. Moreover, as follows from the data of Heidelberger and coworkers [3] on serological relationship between this polysaccharide and two K-specific polysaccharides from Pneumococcus types 2 and 6, it was proposed that rhamnose and galactose residues in the Sh. dysenteriue polysaccharide were substituted at positions 3 and 2 respectively. In spite of these findings, the complete chemical structure of the antigenic polysaccharide from Sh. dysenteriae type 1 has not previously been established.In the course of systematic structural investigations on Sh. dysenteriae lipopolysaccharides, we have performed the chemotyping of all ten lipopolysaccharides of this subgroup [4], determined the structures of polysaccharide chains of serotypes 3 [5,6] and 6 [7], and discovered a new type of acidic monosaccharides [8] which were found to be the components of these O-antigens.

Somatic antigens of Pseudomonas aeruginosa. The structure of O-specific polysaccharide chains of the lipopolysaccharides from P. aeruginosa O5 (Lanyi) and immunotype 6 (Fisher)

“…Ion-exchange chromatography was carried out on a column (20 x 1 cm) of DEAE-Trisacryl M. Elution profiles were recorded by using a Technicon sugar analyzer. Monosaccharides were determined with a Technicon sugar analyzer and a BC-200 amino acid analyzer as described earlier [15].…”

Somatic Antigens of Pseudomonas aeruginosa

“…Elution curves were recorded with a Technicon sugar analyzer. Aminosugdrs were analyzed with a BC-200 amino acid analyzer, as described previously in [8].…”

Somatic Antigens of Pseudomonas aeruginosa

“…Elution curves were recorded using a Technicon sugar analyser. Ion-exchange chromatography of amino sugars was conducted on a BC-200 amino acid analyzer as previously described in [9].…”

“…Elution curves were recorded using a Technicon sugar analyser. Ion-exchange chromatography of amino sugars was conducted on a BC-200 amino acid analyzer as previously described in [9].Gas-liquid chromatography was performed on a Pye Unicam instrument series 104 (model 64), on a glass column ( 1 5 0~0 . 4 cm) with 3% OV-I on diatomite CQ (100-120 mesh), carrier gas nitrogen, flow rate 45 ml/min.…”