Isolation and characterization of F12 adhesive fimbrial antigen from uropathogenic Escherichia coli strains.

The adhesive fimbrial antigen F12 from a strain of uropathogenic Escherichia coli has been isolated and characterized. The antigen was purified by ammonium sulfate precipitation and gel chromatography. The protein subunit of the F12 fimbria has a molecular weight of 18,200; the N-terminal amino acid sequence of the subunit shows close resemblance to that of the subunits of other F fimbriae and the type 1 fimbriae. We identified in these proteins a pattern of alternating conserved and variable amino acid residues which could indicate a special structural and functional feature.