Reactivity of isolated lipopolysaccharides of enterobacterial R mutants with complete or incomplete core structures with lectins.

Alkali-treated lipopolysaccharides of a range of enterobacterial R mutants with complete and incomplete core structures were investigated by agar gel and microcapillary precipitation onto their reactivity with three selected commercial lectins, namely Concanavalin A, Ricinus communis agglutinin and Wheat germ agglutinin. R lipopolysaccharides with complete R cores of the six so far established core types were differentiable from each other by their characteristic lectin reactivity pattern. One core type showed no reaction with all the three lectins. R lipopolysaccharides with incomplete core structure showed in general the reactivity pattern predictable from their individual chemical configuration. It was further shown that substitution of complete R cores by haptens (T1, T2 or ECA) or by a single repeating unit (SR mutant) did not change the reactivity pattern, although some interactions were less pronounced. It will be demonstrated that lectin precipitation can be of help for structural studies in recognizing, for example, terminal sugar units and their anomeric linkages.