Showing papers by "Edgardo Moreno published in 1979"

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.

Brucella Abortus Lipopolysaccharide Is Mitogenic for Spleen Cells of Endotoxin-Resistant C3H/HeJ Mice

Abstract: Preparations of lipopolysaccharide (LPS) from rough and smooth strains of Brucella abortus were mitogenic for spleen cells of athymic nude mice, C3H/HeAU mice, and the endotoxin-resistant C3H/HeJ mice. The mitogenic response induced by crude smooth-LPS (f 5 ) was greater than that produced by purified smooth-LPS (f 5p ); however, the dose-response curves were similar for both preparations. The mitogenic activity of mouse spleen cells to both f 5 and f 5p was higher than that produced by stimulation with purified rough-LPS. The dose-response curves with rough-LPS were also qualitatively different from those produced with the preparations of smooth-LPS.