Characterization of the lipopolysaccharide from Actinobacillus actinomycetemcomitans Y4 and N27.

The lipopolysaccharide (LPS) from Actinobacillus actinomycetemcomitans strains Y4 and N27 was isolated by the phenol-water procedure. Morphologically, the molecule consisted of ribbon and branched filaments which comprised 3% of the cellular dry weight. Chemical analysis of the isolated and purified LPSs of both strains showed them to consist of carbohydrate, lipid, 2-keto-3-deoxyoctonate, heptose, hexosamine, and phosphate. The major fatty acids of the lipid A moiety were saturated C14 and beta-OH C14 compounds. Rhamnose, fucose, galactose, glucose, heptose, glucosamine, and galactosamine comprised the monosaccharide portion of the LPS. Biological activity studies revealed both LPS molecules to be active in the Schwartzman reaction and in in vitro 45Ca bone resorption, as well as in macrophage activation and lethality and in platelet aggregation.