Low-molecular-weight polysaccharide antigens isolated from Rhodopseudomonas gelatinosa.
Strain-specific low-molecular-weight polysaccharides of different chemical compositions were obtained from cells of nine different wild-type strains of the phototrophic bacterium Rhodopseudomonas gelatinosa. The polysaccharides are free of typical capsule components like hexuronic or aminohexuronic acids but contain (except that of strain 39/2) substantial amounts of phosphorus. A number of unusual o-methyl sugars (2-o-methyl-D-galactose, 2,3-di-o-methyl-D-galactose, 2-o-methyl-L-fucose) as well as 3,6-dideoxy-D-xylo-hexose (abequose) were identified in the R. gelatinosa polysaccharides. o-Methyl and dideoxy sugars however, are typical constituents of O-specific chains of the lipopolysaccharides of gram-negative bacteria (Rhodospirillaceae and Enterobacteriaceae, respectively). Considering both the R-type character of the R. gelatinosa lipopolysaccharides and the occurrence of these strain-specific ETEROPOLYSACCHARIDES, THE ASSUMPTION SEEMS TO BE JUSTIFIED THAT THE LOW-MOLECULAR-WEIGHT POLYSACCHARIDES ARE RELATED TO O-specific chains of lipopolysaccharides (haptens) rather than to capsular or slime antigens. In serological terms the polysaccharides of R. gelatinosa have to be classified as K-antigens. They are able to cover the O-specificity of the respective different strains and confer on them additional specificity which is demonstrable by bacterial agglutination.
D003429:Cross Reactions; D003837:Deoxy Sugars / Q000032:analysis; D005643:Fucose / Q000032:analysis; D005690:Galactose / Q000032:analysis; D005944:Glucosamine / Q000032:analysis; D006601:Hexoses / Q000032:analysis; D007536:Isomerism; D008358:Mannose / Q000032:analysis; D008970:Molecular Weight; D010758:Phosphorus / Q000032:analysis; D011135:Polysaccharides, Bacterial / Q000032:analysis* / Q000276:immunology; D012210:Rhamnose / Q000032:analysis; D012241:Rhodopseudomonas / Q000032:analysis / Q000276:immunology*; D012703:Serotyping; D013045:Species Specificity
D003837:Deoxy Sugars; D006601:Hexoses; D011135:Polysaccharides, Bacterial; D010758:Phosphorus; D005643:Fucose; C023708:abequose; D005944:Glucosamine; D008358:Mannose; D012210:Rhamnose; D005690:Galactose