Evidence for a bilayer structure in gram-negative lipopolysaccharide: relationship to toxicity.

Additional evidence for a bilayer structure in isolated gram-negative lipopolysaccharide (LPS) is demonstrated. Both heating in an electron beam and cleavage of ester-bound fatty acids by alkali were found to split the bilayer structure of LPS into apparent monolayers. The altered structure of LPS resulting from alkaline hydrolysis may explain some of the altered biological activities possessed by the hydrolyzed product.