A specific polysaccharide of Pasteurella pestis

Abstract

Acetone-dried cells of Pasteurella pestis were extracted with aqueous phenol (45%, w/v), after removal of proteins by saline extraction, and a specific lipopolysaccharide was obtained. The polysaccharide was purified by ethanol fractionation and ultracentrifugation. The purified material is poorly soluble in water and insoluble in salt solutions. Analysis showed 1.6% N, 2.2% P; ([alpha])[image] was - 48[degree]; relative viscosity at 1% (w/v) in water at 20[degree] was t This symbol (t) before abstract number indicates an abstract edited by the editor(s) of the source journal, and republished unaltered by BA editorial staff. 40. Mild acid hydrolysis released in about equal amounts a chloroform-soluble phospholipid and a degraded polysaccharide having 1% N, 1% P, ([alpha])[image] - 58[degree]. The lipopolysaccharide is of very large particle D size and sediments as one component in the analytical ultracentrifuge. The degraded polysaccharide has quite a low molecular weight, probably of the order of 10,000 -15,000. The lipopolysaccharide contains glucose, glucosamine and an unidentified aldoheptose sugar which comprises the greater part of the polysaccharide moiety. Immunological homogeneity was demonstrated by the agar-diffusion-precipitin technique. The lipopolysaccharide is a haptene. It can be made antigenic by combination with the conjugated-protein component of the somatic antigen of Shigella dysenteriae. The degraded polysaccharide does not precipitate with specific polysaccharide antisera but inhibits precipitation of the lipopolysaccharide with such sera. The material can be extracted from rough and smooth strains, is non-protective, relatively non-toxic, but strongly pyrogenic.