title: On the serological specificity of the Escherichia coli O8 and O9 antigens.
abstract: The O8 and O9-specific lipopolysaccharides of Escherichia coli lost their serological activity during liberation of the polysaccharide moieties (alpha-mannans) by mild acid hydrolysis, as tested by passive haemagglutination and haemagglutination inhibition. The serological activities and specificities were restored by substitution of the polysaccharides with 1 to 2 stearoyl groups per polysaccharide chain. The mannans obtained by biosynthesis in vitro were serologically active only when bound to the membrane-associated hydrophobic carrier molecule. Liberation of the polysaccharides from the carrier by treatment with aqueous phenol resulted in loss of the serological activity. The O8- and O9-specific mannans of E. coli are thus serologically active when they are part of an amphiphilic molecule and not as free polysaccharides.
mesh_terms: D000937:Antigen-Antibody Reactions; D000939:Epitopes; D004926:Escherichia coli / Q000276:immunology* / Q000378:metabolism; D006386:Hemagglutination Tests; D008070:Lipopolysaccharides / Q000276:immunology* / Q000378:metabolism; D008351:Mannans / Q000378:metabolism; D011135:Polysaccharides, Bacterial / Q000276:immunology*
chemical_list: D000939:Epitopes; D008070:Lipopolysaccharides; D008351:Mannans; D011135:Polysaccharides, Bacterial