Immunobiological biochemical and physico-chemical characteristics of Brucella lipopolysaccharide subjected to various doses of gamma radiation.

A comparative study of toxicity, serological activity, some biochemical and physico-chemical properties of the highly toxic Brucella lipopolysaccharide (LPS) and of preparations obtained after the action of gamma radiation in doses of 1.3 and 10 mrad on the antigen. The toxicity of LPS was found to decrease with the increasing dose of irradiation. Irradiation with a dose of 3 mrad produced a marked decrease in the toxicity of the antigen without causing essential changes in its serological properties. The process of LPS detoxication under the effect of irradiation was accompanied by changes in certain biochemical and physico-chemical indices suggestive of the modification of the primary structure of the LPS molecule and of impairment of mainly its polysaccharide side chains.