Binding specificity of Salmonella plasmid-encoded fimbriae assessed by glycomics

J Biol Chem. 2008 Mar 28;283(13):8118-24. doi: 10.1074/jbc.M710095200. Epub 2008 Jan 22.

Abstract

The Salmonella enterica serotype Typhimurium (S. Typhimurium) genome encodes 12 intestinal colonization factors of the chaperone/usher fimbrial assembly class; however, the binding specificity is known for only one of these adhesins, known as type 1 fimbriae. Here we explored the utility of glycomics to determine the carbohydrate binding specificity of plasmid-encoded fimbriae from S. Typhimurium. A cosmid carrying the pef operon was introduced into Escherichia coli and expression of fimbrial filaments composed of PefA confirmed by flow cytometry and immune-electron microscopy. Plasmid-encoded fimbriae were purified from the surface of E. coli, and the resulting preparation was shown to contain PefA as the sole major protein component. The binding of purified plasmid-encoded fimbriae to a glycanarray suggested that this adhesin specifically binds the trisaccharide Galbeta1-4(Fucalpha1-3)GlcNAc, also known as the Lewis X (Le(x)) blood group antigen. Results from the glycanarray were validated by enzyme-linked immunosorbent assay (ELISA) in which plasmid-encoded fimbriae bound Le(x)-coated wells in a concentration-dependent manner. The binding of plasmid-encoded fimbriae to Le(x)-coated wells could be inhibited by co-incubation with soluble Le(x) antigen. Our results establish glycomic analysis as a promising new approach for determining the carbohydrate binding specificity of bacterial adhesins.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acid Sequence
  • Carbohydrate Metabolism
  • Fimbriae Proteins / chemistry
  • Fimbriae Proteins / genetics
  • Fimbriae Proteins / metabolism
  • Fimbriae, Bacterial / chemistry
  • Fimbriae, Bacterial / genetics*
  • Fimbriae, Bacterial / metabolism*
  • Fimbriae, Bacterial / ultrastructure
  • Gene Expression Regulation, Bacterial
  • Glycomics*
  • Ligands
  • Microscopy, Immunoelectron
  • Molecular Sequence Data
  • Plasmids / genetics*
  • Plasmids / isolation & purification
  • Salmonella / genetics*
  • Salmonella / metabolism*

Substances

  • Ligands
  • Fimbriae Proteins