title: Characterization of the lipid A component of genuine smooth-form lipopolysaccharide.
abstract: The smooth-form lipopolysaccharide of Salmonella abortus equi had earlier been separated into three distinct fractions, a long-chain fraction with an O chain containing 20-50 repeating units, a short-chain fraction consisting of an R lipopolysaccharide and another with 1-6 repeating units, and an R fraction identical to the lipopolysaccharide synthesized by Ra.b-mutant bacteria [Galanos et al. (1988) J. Chromatogr. 440, 397-404]. In this paper, the corresponding lipid A from each fraction was prepared by a newly elaborated procedure based on hydrolysis of the fractions in calcium acetate buffer (pH 3.5) followed by separation of the resulting free lipid A from the polysaccharide on a Sephadex G-100 column. Chemical analysis revealed that lipid A of the R fraction contained the expected spectrum and amounts of fatty acids and it proved to be structurally identical to lipid A of previously studied Salmonella R mutants. In contrast, the lipid A of the long-chain fraction contained only about 60% fatty acids compared to that of the R fraction. The lipid A of the short-chain fraction also expressed a reduced substitution pattern of acyl residues.
authors.affiliation: Max-Planck-Institut für Immunbiologie, Freiburg-Zähringen, Federal Republic of Germany.
authors.forename: B H
authors.initials: BH
authors.lastname: Jiao
authors.forename: M
authors.initials: M
authors.lastname: Freudenberg
authors.forename: C
authors.initials: C
authors.lastname: Galanos
mesh_terms: D000085:Acetates; D019342:Acetic Acid; D000577:Amides / Q000032:analysis; D002855:Chromatography, Thin Layer; D005227:Fatty Acids / Q000032:analysis; D006868:Hydrolysis; D008050:Lipid A / Q000032:analysis*; D008070:Lipopolysaccharides / Q000032:analysis*; D011134:Polysaccharides / Q000032:analysis*; D012475:Salmonella / Q000032:analysis*
chemical_list: D000085:Acetates; D000577:Amides; D005227:Fatty Acids; D008050:Lipid A; D008070:Lipopolysaccharides; D011134:Polysaccharides; D019342:Acetic Acid