[Comparative study of lipid A from pertussis microbes differing in the toxicity of their O-antigens. I. Chemical composition and stability of the bond between lipid A and the specific polysaccharide in B. pertussis lipopolysaccharide].

Data presented in this work indicated that antigens, contrastive by toxicity, obtained by Boiven's method and O'Neill and Tood's method from two strains of Bordetella pertussis differed by stability of lipid A binding with the specific polysaccharide. The influence of duration of the lipopolysaccharide hydrolysis on the fatty acid content in lipid A, and of heptose in the specific polysaccharide was demonstrated. Lipid A fatty acid composition was studied. It is supposed that bound fatty acids are presented as C14 and C19--C22. There was a correlation between the antigen toxicity and the stability of lipid A bond with the specific polysaccharide. Stability of the lipopolysaccharide complex bond depended on heptose and lipid A content and on the composition and the amount of fatty acids in the lipid A preparations.