Purification and characterization of the Dr hemagglutinins expressed by two uropathogenic Escherichia coli strains.

The fibrillar Dr hemagglutinins expressed by two uropathogenic Escherichia coli isolates were mechanically sheared from whole cells and subsequently purified by using anion-exchange high-pressure liquid chromatography. The isolated hemagglutinins were proteins with apparent subunit molecular masses of 14,500 daltons by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric points of 5.4 in denaturing isoelectric focusing gels. The two proteins were serologically related to each other but distinct from P fimbriae, as assessed by bacterial agglutination and immunoblotting. The amino acid compositions of the two hemagglutinins were highly similar both to each other and to other Dr hemagglutinins. N-terminal amino acid sequencing of the major hemagglutinin subunit proteins demonstrated homology with afimbrial E. coli adhesins.