Mannose-sensitive and Gal-Gal binding Escherichia coli pili from recombinant strains. Chemical, functional, and serological properties.

Abstract

Chromosomal genes encoding the MS and Gal-Gal binding properties have been cloned into separate recombinants and their respective pili characterized. Hapten inhibition of hemagglutination with synthetic carbohydrate receptor analogues and carbohydrate-adsorbed latex agglutination studies indicate that Gal-Gal and MS pili collectively exhibit the binding properties of the parent strain. MS pili migrated in SDS-PAGE with an Mr of 19 kdaltons and 17 kdaltons; the Mr of Gal-Gal pili was 17.5 kdaltons. The pili are chemically similar by amino acid composition and when the N-terminal cysteines are aligned, 8 of the 13 residues between positions 9 and 22 are homologous. Further, carboxy-terminal sequence homology was inferred from the carboxypeptidase digestion of a MS pili and the sequence of a carboxy-terminal tryptic peptide from Gal-Gal pili.

Virulence factors in Escherichia coli urinary tract infection

“…Similarity to Other Fimbriae PapA exhibits a moderate degree of amino acid homology at the amino terminus with the structural subunits of type 1 and other fimbriae of E. coli (269,392,428,521). The overall arrangement of the P-fimbrial gene cluster is similar to, although distinct from, the arrangement of gene clusters encoding S, F1C, and type 1 fimbriae of E. coli ( Fig.…”

“…The conserved amino acids are hydrophobic and are presumably oriented toward the interior of the mature protein, playing an essential structural role while avoiding immunological selective pressure (326,568,569). In contrast, there is great variation in the primary structure of the central portions of PapA, possibly because this area is hydrophilic, exposed, and subject to maximal selective pressure from the host immune system while being nonessential for fimbrial function (274,326,392,569). In many instances, there is also substantial heterogeneity between different P-fimbrial types with respect to the amino acid sequences of the minor fimbrial subunits (PapE, PapF, and PapG) (195,325,326).…”

“…Despite their serologic heterogeneity, PapA molecules from different P-fimbrial serovariants exhibit a high degree of amino acid homology at the N and C termini (185,269,273,274,392,468,469,568). The conserved amino acids are hydrophobic and are presumably oriented toward the interior of the mature protein, playing an essential structural role while avoiding immunological selective pressure (326,568,569).…”

Gal-Gal pili vaccines prevent pyelonephritis by piliated Escherichia coli in a murine model. Single-component Gal-Gal pili vaccines prevent pyelonephritis by homologous and heterologous piliated E. coli strains.

“…Presence of pili-specific IgG, IgA, and IgM was assessed in serum and urine by ELISA (12,14). Polystyrene microtiter wells were coated with 100 ng of pili from each of the preparations in 100 gl of 0.1 M sodium carbonate buffer, pH 9.6, for 24 h at 37°C.…”

“…Also, the possibility exists that there are protective clonal epitopes within the major pilin polypeptide of Gal-Gal pili. (Sigma Chemical Co., St. Louis, MO) and by slide agglutination of latex particles that had synthetic Gal-Gal bound to their surface (Chembiomed, Ltd., Edmonton, Alberta, Canada) (14). The number of colony-forming units (CFU) of these bacteria per milliliter PBS was determined by OD at 600 nm (wavelength of light path = I cm) and confirmed by a standard laboratory agar pour technique.…”