Interaction of Escherichia coli K88 antigen with porcine intestinal brush border membranes.

The fimbria-associated Escherichia coli antigen, K88, was purified to homogeneity as determined by polyacrylamide gel electrophoresis and immunodiffusion. This polymeric antigen consists of noncovalently linked subunits, containing little or no carbohydrate, and has a monomeric molecular weight of 23,000. When a binding assay employing differential filtration was used, K88 formed complexes with isolated porcine intestinal brush border membranes. The formation of complexes was inhibited by glycoproteins with terminal N-acetylglucosamine and N-acetylgalactosamine residues and to a lesser extent by free N-acetylhexosamines. These amino sugars may play a role in the interaction of this pathogenic strain of E. coli with the intestinal epithelia of pigs.