Immunological and Physicochemical Characterization of Heat-Labile Enterotoxins Isolated from Two Strains of Escherichia coli

Heat-labile enterotoxins from Escherichia coli strains of human and porcine origins had identical subunit composition, arrangement, and size in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Immunological differences recently described by others were shown to reside exclusively in the B subunits.