| 1. |
- Nilsson, Ulf, et al.
(författare)
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PapG adhesin from E. coli J96 recognizes the same saccharide epitope when present on whole bacteria and as isolated protein
- 1996
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Ingår i: Bioorganic and Medicinal Chemistry. - 0968-0896. ; 4:11, s. 1809-1817
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Tidskriftsartikel (refereegranskat)abstract
- Purified PapG adhesin from the genetically well-defined uropathogenic Escherichia coli strain J96, as well as whole bacteria, were bound to microtiter plates that carried covalently bound globotetraose and galabiose. The binding was inhibited by soluble saccharide derivatives corresponding to the globoseries of glycolipids, including all di-, tri-, tetra-, and pentasaccharide fragments of the Forssman antigen and all monodeoxy analogues of galabiose. Analysis of the inhibition pattern showed no significant difference between purified adhesin and whole bacteria. The glucose unit at the reducing end of the natural saccharides was detrimental to PapG binding since deletion of the glucose unit increased the inhibitory power 10-20 fold. The five hydroxyl groups HO-6, -2', -3', -4', -6' of the galabiose unit were shown to be important for PapG binding, presumably via intermolecular hydrogen bonds.
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| 2. |
- Striker, Robert, et al.
(författare)
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Structural requirements for the glycolipid receptor of human uropathogenic Escherichia coli
- 1995
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Ingår i: Molecular Microbiology. - : Wiley. - 0950-382X .- 1365-2958. ; 16:5, s. 1021-1029
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Tidskriftsartikel (refereegranskat)abstract
- The binding of uropathogenic Escherichia coli to the globo series of glycolipids via P pili is a critical step in the infectious process that is mediated by a human‐specific PapG adhesin. Three classes of PapG adhesins exist with different binding specificities to Galα4Gal‐containing glycolipids. The structural basis for PapG recognition of the human glycolipid receptor globoside was investigated by using soluble saccharide analogues as inhibitors of bacterial haemagglutination. The minimum binding epitope was confirmed as the Galα4Gal moiety, but parts of the GalNAcβ and glucose residues, which flank the Galα4Gal in globoside (GbO4), were also shown to be important for strong binding. Furthermore, the same five hydroxyl groups of Galα4Gal in globotriasyl ceramide that were recognized by a previously characterized PapG variant were also recognized by the human‐specific PapG in binding the GbO4 that dominates In the human kidney. Saccharide analogues that blocked haemagglutination also blocked the adherence of human uropathogenic E. coli to human kidney sections. Knowledge of the molecular details of the PapG‐GbO4 interaction will make it possible to design antiadherence therapeutics.
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