Somatic antigen of Shigella dysenteriae type 3. Structural features of specific polysaccharide chain.

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.