| 1. |
- Ohlsson, Jörgen, et al.
(författare)
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Structure–activity relationships of galabioside derivatives as inhibitors of E. coli and S. suis adhesins: nanomolar inhibitors of S. suis adhesins
- 2005
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Ingår i: Organic and Biomolecular Chemistry. - : Royal Society of Chemistry (RSC). - 1477-0539 .- 1477-0520. ; 3:5, s. 886-900
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Tidskriftsartikel (refereegranskat)abstract
- Four collections of Gal1-4Gal derivatives were synthesised and evaluated as inhibitors of the PapG class II adhesin of uropathogenic Escherichia coli and of the PN and PO adhesins of Streptococcus suis strains. Galabiosides carrying aromatic structures at C1, methoxyphenyl O-galabiosides in particular, were identified as potent inhibitors of the PapG adhesin. Phenylurea derivatisation at C3 and methoxymethylation at O2 of galabiose provided inhibitors of the S. suis strains type PN adhesin with remarkably high affinities (30 and 50 nM, respectively). In addition, quantitative structure–activity relationship models for E. coli PapG adhesin and S. suis adhesin type PO were developed using multivariate data analysis. The inhibitory lead structures constitute an advancement towards high-affinity inhibitors as potential anti-adhesion therapeutic agents targeting bacterial infections.
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| 2. |
- Dzhambazov, Balik, et al.
(författare)
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The major T cell epitope on type II collagen is glycosylated in normal cartilage but modified by arthritis in both rats and humans
- 2005
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Ingår i: European Journal of Immunology. - : Wiley. - 1521-4141 .- 0014-2980. ; 35:2, s. 357-366
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Tidskriftsartikel (refereegranskat)abstract
- Type II collagen (CII) is a target for autoreactive T cells in both rheumatoid arthritis and the murine model collagen-induced arthritis. The determinant core of CII has been identified as CII260-270, and the alteration of this T cell epitope by posttranslational modifications is known to be critical for development of arthritis in mice. Using CII-specific T cell hybridomas we have now shown that the immunodominant T cell epitope in the normal (healthy) human and rat joint cartilage is O-glycosylated at the critical T cell receptor recognition position 264 with a mono- or di-saccharide attached to a hydroxylysine. In contrast, in the arthritic human and rat joint cartilage there are both glycosylated and non-glycosylated CII forms. Glycosylated CII from normal cartilage could not be recognized by T cells reactive to peptides having only lysine or hydroxylysine at position 264, showing that antigen-presenting cells could not degrade the O-linked carbohydrate. Thus, the variable forms of the glycosylated epitope are determined by the structures present in cartilage, and these vary during the disease course. We conclude that the chondrocyte determines the structures presented to the immune system and that these structures are different in normal versus arthritic states.
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| 3. |
- Hedenström, Mattias, et al.
(författare)
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NMR studies of interactions between periplasmic chaperones from uropathogenic E-coli and pilicides that interfere with chaperone function and pilus assembly
- 2005
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Ingår i: ORGANIC & BIOMOLECULAR CHEMISTRY. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 3:23, s. 4193-4200
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Tidskriftsartikel (refereegranskat)abstract
- Adherence of uropathogenic Escherichia coli to host tissue is mediated by pili, which are hair-like protein structures extending from the outer cell membrane of the bacterium. The chaperones FimC and PapD are key components in pilus assembly since they catalyse folding of subunits that are incorporated in type 1 and P pili, respectively, and also transport the subunits across the periplasmic space. Recently, compounds that inhibit pilus biogenesis and interfere with chaperone-subunit interactions have been discovered and termed pilicides. In this paper NMR spectroscopy was used to study the interaction of different pilicides with PapD and FimC in order to gain structural knowledge that would explain the effect that some pilicides have on pilus assembly. First relaxation-edited NMR experiments revealed that the pilicides bound to the PapD chaperone with mM affinity. Then the pilicide-chaperone interaction surface was investigated through chemical shift mapping using N-15-labelled FimC. Principal component analysis performed on the chemical shift perturbation data revealed the presence of three binding sites on the surface of FimC, which interacted with three different classes of pilicides. Analysis of structure-activity relationships suggested that pilicides reduce pilus assembly in E. coli either by binding in the cleft of the chaperone, or by influencing the orientation of the flexible F1-G1 loop, both of which are part of the surface by which the chaperone forms complexes with pilus subunits. It is suggested that binding to either of these sites interferes with folding of the pilus subunits, which occurs during formation of the chaperone-subunit complexes. In addition, pilicides that influence the F1-G1 loop also appear to reduce pilus formation by their ability to dissociate chaperone-subunit complexes.
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| 4. |
- Holm, L, et al.
(författare)
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Identification of the minimal glycopeptide core recognized by T cells in a model for rheumatoid arthritis
- 2005
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Ingår i: Bioorganic & Medicinal Chemistry. - Oxford : Elsevier BV. - 0968-0896 .- 1464-3391. ; 13:2, s. 473-482
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Tidskriftsartikel (refereegranskat)abstract
- Collagen induced arthritis (CIA) is a common mouse model for rheumatoid arthritis. Two sets of truncated peptides derived from type II collagen have been prepared and tested for binding to A(q), a MHC-II molecule associated with development of CIA. Binding to A(q) correlated well with predictions from a computer-based model. T-cell hybridomas, obtained in CIA, were also used to study the ability of A(q) bound peptides to trigger a T-cell response. The minimal peptide epitope required for binding, as well as for giving a T-cell response, was determined to be CII260-267. In collagen this epitope is often glycosylated at hydroxylysine 264 and glycosylation has been shown to be an immunodominant feature in CIA. Synthesis and evaluation of CII260-267 carrying a beta-D-galactosyl moiety at position 264 revealed that this glycopeptide stimulated representative members from a panel of carbohydrate-specific T-cell hybridomas obtained in CIA.
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| 5. |
- Larsson, Andreas, et al.
(författare)
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Multivariate design, synthesis, and biological evaluation of peptide inhibitors of FimC/FimH protein-protein interactions in uropathogenic Escherichia coli
- 2005
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 48:4, s. 935-945
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Tidskriftsartikel (refereegranskat)abstract
- A peptide library targeting protein-protein interactions crucial for pilus assembly in Gram negative bacteria has been designed using statistical molecular design. A nonamer peptide scaffold was used, with seven positions being varied. The selection was performed in the building block space, and previously known structure-activity data were included in the design procedure. This resulted in a heavily reduced library consisting of 32 peptides which was prepared by solid-phase synthesis. The ability of the peptides to inhibit the protein-protein interaction between the periplasmic chaperone FimC and the pilus adhesin FimH was then determined in an ELISA. Novel peptides with the capability to inhibit the FimC/FimH protein(-)protein interaction to the same extent as the native FimC peptides were discovered. Multivariate QSAR studies of the response in the ELISA gave valuable information on the properties of amino acids which were preferred at the seven positions in the nonamer scaffold. This information can be used in attempts to develop optimized peptides and peptidomimetics that inhibit pilus assembly in pathogenic bacteria.
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