| 1. |
- Chorell, Erik, 1980-, et al.
(författare)
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Design and synthesis of C-2 substituted Thiazolo and Dihydrothiazolo ring-fused 2-Pyridones : pilicides with increased antivirulence activity
- 2010
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Ingår i: Journal of Medicinal Chemistry. - Washington, USA : American Chemical Society. - 0022-2623 .- 1520-4804. ; 53:15, s. 5690-5695
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Tidskriftsartikel (refereegranskat)abstract
- Pilicides block pili formation by binding to pilus chaperones and blocking their function in the chaperone/usher pathway in E. coli. Various C-2 substituents were introduced on the pilicide scaffold by design and synthetic method developments. Experimental evaluation showed that proper substitution of this position affected the biological activity of the compound. Aryl substituents resulted in pilicides with significantly increased potencies as measured in pili-dependent biofilm and hemagglutination assays. The structural basis of the PapD chaperone-pilicide interactions was determined by X-ray crystallography.
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| 2. |
- D'Ascenzo, Fabrizio, et al.
(författare)
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Incidence and predictors of coronary stent thrombosis : Evidence from an international collaborative meta-analysis including 30 studies, 221,066 patients, and 4276 thromboses
- 2013
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Ingår i: International Journal of Cardiology. - : Elsevier BV. - 0167-5273 .- 1874-1754. ; 167:2, s. 575-584
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:Stent thrombosis remains among the most feared complications of percutaneous coronary intervention (PCI) with stenting. However, data on its incidence and predictors are sparse and conflicting. We thus aimed to perform a collaborative systematic review on incidence and predictors of stent thrombosis.METHODS: PubMed was systematically searched for eligible studies from the drug-eluting stent (DES) era (1/2002-12/2010). Studies were selected if including ≥2000 patients undergoing stenting or reporting on ≥25 thromboses. Study features, patient characteristics, and incidence of stent thrombosis were abstracted and pooled, when appropriate, with random-effect methods (point estimate [95% confidence intervals]), and consistency of predictors was formally appraised.RESULTS:A total of 30 studies were identified (221,066 patients, 4276 thromboses), with DES used in 87%. After a median of 22months, definite, probable, or possible stent thrombosis had occurred in 2.4% (2.0%; 2.9%), with acute in 0.4% (0.2%; 0.6%), subacute in 1.1% (1.0%; 1.3%), late in 0.5% (0.4%; 0.6%), and very late in 0.6% (0.4%; 0.8%). Similar figures were computed for studies reporting only on DES. From a total of 47 candidate variables, definite/probable stent thrombosis was more commonly and consistently predicted by early antiplatelet therapy discontinuation, extent of coronary disease, and stent number/length, with acute coronary syndrome at admission, diabetes, smoking status, and bifurcation/ostial disease also proving frequent predictors, but less consistently.CONCLUSIONS:Despite numerous possible risk factors, the most common and consistent predictors of stent thrombosis are early antiplatelet therapy discontinuation, extent of coronary disease, and stent number/length.
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| 3. |
- Pinkner, Jerome S., et al.
(författare)
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Rationally designed small compounds inhibit pilus biogenesis in uropathogenic bacteria
- 2006
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - Washtington : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 103:47, s. 17897-17902
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Tidskriftsartikel (refereegranskat)abstract
- A chemical synthesis platform with broad applications and flexibility was rationally designed to inhibit biogenesis of adhesive pili assembled by the chaperone–usher pathway in Gram-negative pathogens. The activity of a family of bicyclic 2-pyridones, termed pilicides, was evaluated in two different pilus biogenesis systems in uropathogenic Escherichia coli. Hemagglutination mediated by either type 1 or P pili, adherence to bladder cells, and biofilm formation mediated by type 1 pili were all reduced by 90% in laboratory and clinical E. coli strains. The structure of the pilicide bound to the P pilus chaperone PapD revealed that the pilicide bound to the surface of the chaperone known to interact with the usher, the outer-membrane assembly platform where pili are assembled. Point mutations in the pilicide-binding site dramatically reduced pilus formation but did not block the ability of PapD to bind subunits and mediate their folding. Surface plasmon resonance experiments confirmed that the pilicide interfered with the binding of chaperone–subunit complexes to the usher. These pilicides thus target key virulence factors in pathogenic bacteria and represent a promising proof of concept for developing drugs that function by targeting virulence factors.
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| 4. |
- Rothwell, Paul J., et al.
(författare)
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dNTP-dependent Conformational Transitions in the Fingers Subdomain of Klentaq1 DNA Polymerase INSIGHTS INTO THE ROLE OF THE "NUCLEOTIDE-BINDING" STATE
- 2013
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 288:19, s. 13575-13591
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Tidskriftsartikel (refereegranskat)abstract
- DNA polymerases are responsible for the accurate replication of DNA. Kinetic, single-molecule, and x-ray studies show that multiple conformational states are important for DNA polymerase fidelity. Using high precision FRET measurements, we show that Klentaq1 (the Klenow fragment of Thermus aquaticus DNA polymerase 1) is in equilibrium between three structurally distinct states. In the absence of nucleotide, the enzyme is mostly open, whereas in the presence of DNA and a correctly base-pairing dNTP, it re-equilibrates to a closed state. In the presence of a dNTP alone, with DNA and an incorrect dNTP, or in elevated MgCl2 concentrations, an intermediate state termed the "nucleotide-binding" state predominates. Photon distribution and hidden Markov modeling revealed fast dynamic and slow conformational processes occurring between all three states in a complex energy landscape suggesting a mechanism in which dNTP delivery is mediated by the nucleotide-binding state. After nucleotide binding, correct dNTPs are transported to the closed state, whereas incorrect dNTPs are delivered to the open state.
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| 5. |
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| 6. |
- Sayer, James R., et al.
(författare)
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Design, synthesis, and evaluation of peptide-imidazo[1,2-a]pyrazine bioconjugates as potential bivalent inhibitors of the VirB11 ATPase HP0525
- 2021
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Ingår i: Journal of Peptide Science. - : Wiley. - 1075-2617 .- 1099-1387. ; 27:10
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter pylori (H. pylori) infections have been implicated in the development of gastric ulcers and various cancers: however, the success of current therapies is compromised by rising antibiotic resistance. The virulence and pathogenicity of H. pylori is mediated by the type IV secretion system (T4SS), a multiprotein macromolecular nanomachine that transfers toxic bacterial factors and plasmid DNA between bacterial cells, thus contributing to the spread of antibiotic resistance. A key component of the T4SS is the VirB11 ATPase HP0525, which is a hexameric protein assembly. We have previously reported the design and synthesis of a series of novel 8-amino imidazo[1,2-a]pyrazine derivatives as inhibitors of HP0525. In order to improve their selectivity, and potentially develop these compounds as tools for probing the assembly of the HP0525 hexamer, we have explored the design and synthesis of potential bivalent inhibitors. We used the structural details of the subunit-subunit interactions within the HP0525 hexamer to design peptide recognition moieties of the subunit interface. Different methods (cross metathesis, click chemistry, and cysteine-malemide) for bioconjugation to selected 8-amino imidazo[1,2-a]pyrazines were explored, as well as peptides spanning larger or smaller regions of the interface. The IC50 values of the resulting linker-8-amino imidazo[1,2-a]pyrazine derivatives, and the bivalent inhibitors, were related to docking studies with the HP0525 crystal structure and to molecular dynamics simulations of the peptide recognition moieties.
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