title: Purification and characterization of smooth and rough lipopolysaccharides from Brucella abortus.
abstract: In an attempt to obtain pure and well characterized smooth lipopolysaccharide (S-LPS) and rough lipopolysaccharide (R-LPS), smooth and rough strains of Brucella abortus were extracted by two different modifications of the phenol-water method. S-LPS was obtained in the phenol phase, and R-LPS was obtained in the aqueous phase. Further purification was accomplished by treatment with enzymes, detergents, NaI as a chaotropic agent to separate non-covalently bound contaminants, and by gel filtration. The degree of purity of the molecules was determined by chemical and immunological analysis and by electrophoresis in sodium dodecyl sulfate-polyacrylamide gels. Lipid identification by gas-liquid chromatography showed seven major fatty acids. Palmitic acid accounts for about 50%, stearic acid accounts for about 10%, and hydroxylated fatty acids account for less than 5% of total fatty acids. 2-Keto-3-deoxyoctonate but not heptose was detected in the sugar analysis. Protein was found to be firmly bound to S-LPS but not to R-LPS.
mesh_terms: D000942:Antigens, Bacterial / Q000032:analysis; D002003:Brucella abortus / Q000032:analysis* / Q000166:cytology / Q000276:immunology; D005227:Fatty Acids / Q000032:analysis; D008070:Lipopolysaccharides / Q000276:immunology / Q000302:isolation & purification*
chemical_list: D000942:Antigens, Bacterial; D005227:Fatty Acids; D008070:Lipopolysaccharides