| 1. |
- Kirsebom, O. S., et al.
(författare)
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Precise and accurate determination of the B-8 decay spectrum
- 2011
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 83:6
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Tidskriftsartikel (refereegranskat)abstract
- Accurate measurements of the B-8 neutrino spectrum are important for the interpretation of solar neutrino data. Experimentally, the B-8 neutrino spectrum can be obtained from the measurement of the beta-delayed alpha spectrum. We report on an alpha-alpha coincidence measurement performed at the IGISOL facility in Jyvaskyla, Finland. Our measurement allows extensive cross-checks to be performed and gives a more intense neutrino spectrum at high energies compared to the present standard. The deviation reaches 4% at the end point of the spectrum. Below 11 MeV, the deviation is less than 1%.
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| 2. |
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| 3. |
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| 4. |
- Berglund, Martin, et al.
(författare)
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IL-1 receptor-associated kinase M downregulates DSS-induced colitis
- 2010
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Ingår i: Inflammatory Bowel Diseases. - : Oxford University Press (OUP). - 1078-0998 .- 1536-4844. ; 16:10, s. 1778-1786
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Tidskriftsartikel (refereegranskat)abstract
- Background: Ulcerative colitis is associated with increased colon permeability resulting in bacterial translocation into the lamina propria. We investigate the importance of the Toll-like receptor (TLR) regulating protein IL-1 receptor-associated kinase M (IRAK-M) using the erosive dextran sulfate sodium (DSS)-induced model of colitis. Methods: IRAK-M-competent and -incompetent mice were treated with 3% DSS for 5 days followed by 2 days of regular drinking water. Clinical signs of disease were followed for 7 days. At day 7 the mice were sacrificed and plasma and tissue were collected for histopathological examination and analyses of the production of cytokines and chemokines as well as expression of T-cell transcription factors. Results: At day 7 IRAK-M-deficient mice display a reduced total body weight (77.1 +/- 2.1 versus 88.5 +/- 2.0, *P=0.002) and an increased macroscopical (2.7 +/- 0.2 versus 1.6 +/- 0.1, *P 0.002) and histopathological (6.0 +/- 0 versus 3.3 +/- 60.5, *P < 0.001) colon score compared to wildtype mice. Furthermore, IRAK-M-deficient mice have increased colon mRNA expression of proinflammatory cytokines and increased tumor necrosis factor concentrations (41.1 +/- 13.5 versus 12.8 +/- 2.0 pg/mL, *P = 0.010) in plasma. Conclusions: This is the first report examining the role of IRAK-M in colitis. We find that IRAK-M is of critical importance in downregulating induction and progression of DSS colitis, and thereby suggesting that IRAK-M might be a target for future interventional therapies. (Inflamm Bowel Dis 2010; 16: 1778-1786)
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| 5. |
- Cegelski, Lynette, et al.
(författare)
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Small-molecule inhibitors target Escherichia coli amyloid biogenesis and biofilm formation
- 2009
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Ingår i: Nature Chemical Biology. - : Nature Publishing Group. - 1552-4450 .- 1552-4469. ; 5:12, s. 913-919
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Tidskriftsartikel (refereegranskat)abstract
- Curli are functional extracellular amyloid fibers produced by uropathogenic Escherichia coli (UPEC) and other Enterobacteriaceae. Ring-fused 2-pyridones, such as FN075 and BibC6, inhibited curli biogenesis in UPEC and prevented the in vitro polymerization of the major curli subunit protein CsgA. The curlicides FN075 and BibC6 share a common chemical lineage with other ring-fused 2-pyridones termed pilicides. Pilicides inhibit the assembly of type1pili, which are required for pathogenesis during urinary tract infection. Notably, the curlicides retained pilicide activities and inhibited both curli-dependent and type 1–dependent biofilms. Furthermore, pretreatment of UPEC with FN075 significantly attenuated virulence in a mouse model of urinary tract infection. Curli and type 1pili exhibited exclusive and independent roles in promoting UPEC biofilms, and curli provided a fitness advantage in vivo. Thus, the ability of FN075 to block the biogenesis of both curli and type 1pili endows unique anti-biofilm and anti-virulence activities on these compounds.
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| 6. |
- Eifert, S, et al.
(författare)
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Applying the Gender Lens to Risk Factors and Outcome after Adult Cardiac Surgery
- 2014
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Ingår i: Viszeralmedizin. - : S. Karger AG. - 1662-6664. ; 30:2, s. 99-106
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Tidskriftsartikel (refereegranskat)abstract
- <b><i>Background: </i></b>Applying the gender lens to risk factors and outcome after adult cardiac surgery is of major clinical interest, as the inclusion of sex and gender in research design and analysis may guarantee more comprehensive cardiovascular science and may consecutively result in a more effective surgical treatment as well as cost savings in cardiac surgery. <b><i>Methods: </i></b>We have reviewed classical cardiovascular risk factors (diabetes, arterial hypertension, hyperlipidemia, smoking) according to a gender-based approach. Furthermore, we have examined comorbidities such as depression, renal insufficiency, and hormonal influences in regard to gender. Gender-sensitive economic aspects have been evaluated, surgical outcome has been analyzed, and cardiovascular research has been considered from a gender perspective. <b><i>Results: </i></b>The influence of typical risk factors and outcome after cardiac surgery has been evaluated from a gender perspective, and the gender-specific distribution of these risk factors is reported on. The named comorbidities are listed. Economic aspects demonstrated a gender gap. Outcome after coronary and valvular surgeries as well as after heart transplantation are displayed in this regard. Results after postoperative use of intra-aortic balloon pump are shown. Gender-related aspects of clinical and biomedical cardiosurgical research are reported. <b><i>Conclusions: </i></b>Female gender has become an independent risk factor of survival after the majority of cardiosurgical procedures. Severely impaired left ventricular ejection fraction independently predicts survival in men, whereas age does in females.
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| 7. |
- Greene, Sarah E., et al.
(författare)
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Pilicide ec240 Disrupts Virulence Circuits in Uropathogenic Escherichia coli
- 2014
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Ingår i: mBio. - 2161-2129 .- 2150-7511. ; 5:6, s. UNSP e02038-
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Tidskriftsartikel (refereegranskat)abstract
- Chaperone-usher pathway (CUP) pili are extracellular organelles produced by Gram-negative bacteria that mediate bacterial pathogenesis. Small-molecule inhibitors of CUP pili, termed pilicides, were rationally designed and shown to inhibit type 1 or P piliation. Here, we show that pilicide ec240 decreased the levels of type 1, P, and S piliation. Transcriptomic and proteomic analyses using the cystitis isolate UTI89 revealed that ec240 dysregulated CUP pili and decreased motility. Paradoxically, the transcript levels of P and S pilus genes were increased during growth in ec240, even though the level of P and S piliation decreased. In contrast, the most downregulated transcripts after growth in ec240 were from the type 1 pilus genes. Type 1 pilus expression is controlled by inversion of the fimS promoter element, which can oscillate between phase on and phase off orientations. ec240 induced the fimS phase off orientation, and this effect was necessary for the majority of ec240's inhibition of type 1 piliation. ec240 increased levels of the transcriptional regulators SfaB and PapB, which were shown to induce the fimS promoter phase off orientation. Furthermore, the effect of ec240 on motility was abolished in the absence of the SfaB, PapB, SfaX, and PapX regulators. In contrast to the effects of ec240, deletion of the type 1 pilus operon led to increased S and P piliation and motility. Thus, ec240 dysregulated several uropathogenic Escherichia coli (UPEC) virulence factors through different mechanisms and independent of its effects on type 1 pilus biogenesis and may have potential as an antivirulence compound. IMPORTANCE CUP pili and flagella play active roles in the pathogenesis of a variety of Gram-negative bacterial infections, including urinary tract infections mediated by UPEC. These are extremely common infections that are often recurrent and increasingly caused by antibiotic-resistant organisms. Preventing piliation and motility through altered regulation and assembly of these important virulence factors could aid in the development of novel therapeutics. This study increases our understanding of the regulation of these virulence factors, providing new avenues by which to target their expression.
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| 8. |
- Hannan, T. J., et al.
(författare)
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Inhibition of cyclooxygenase-2 prevents chronic and recurrent cystitis
- 2014
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Ingår i: EBioMedicine. - : Elsevier. - 2352-3964. ; 1:1, s. 46-57
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Tidskriftsartikel (refereegranskat)abstract
- The spread of multidrug-resistant microorganisms globally has created an urgent need for novel therapeuticstrategies to combat urinary tract infections (UTIs). Immunomodulatory therapy may provide benefit, as treatmentof mice with dexamethasone during acute UTI improved outcome by reducing the development of chroniccystitis, which predisposes to recurrent infection. Herewe discovered soluble biomarkers engaged inmyeloid celldevelopment and chemotaxis that were predictive of future UTI recurrence when elevated in the sera of youngwomen with UTI. Translation of these findings revealed that temperance of the neutrophil response early duringUTI, and specifically disruption of bladder epithelial transmigration of neutrophils by inhibition ofcyclooxygenase-2, protected mice against chronic and recurrent cystitis. Further, proteomics identified bladderepithelial remodeling consequent to chronic infection that enhances sensitivity to neutrophil damage. Thus, cyclooxygenase-2 expression during acute UTI is a critical molecular trigger determining disease outcome anddrugs targeting cyclooxygenase-2 could prevent recurrent UTI.
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| 9. |
- Kirsebom, O. S., et al.
(författare)
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The 8B neutrino spectrum
- 2010
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Ingår i: 11th Symposium on Nuclei in the Cosmos, NIC 2010; Heidelberg; Germany; 19 July 2010 through 23 July 2010. - 1824-8039.
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Konferensbidrag (refereegranskat)abstract
- Knowledge of the energy spectrum of the neutrinos emitted in the β decay of8B in the Sun is needed to interpret the neutrino spectrum measured on Earth. Experimentally, the 8B neutrino spectrum may be αextracted from the measurement of the β -delayed a spectrum. In this contribution, the results of a recent α-α coincidence measurement are presented and compared to previous measurements. The implications for the neutrino spectrum are clarified.
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| 10. |
- 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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| 11. |
- Omattage, Natalie S., et al.
(författare)
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Structural basis for usher activation and intramolecular subunit transfer in P pilus biogenesis in Escherichia coli
- 2018
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Ingår i: Nature Microbiology. - : NATURE PUBLISHING GROUP. - 2058-5276. ; 3:12, s. 1362-1368
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Tidskriftsartikel (refereegranskat)abstract
- Chaperone-usher pathway pili are extracellular proteinaceous fibres ubiquitously found on Gram-negative bacteria, and mediate host-pathogen interactions and biofilm formation critical in pathogenesis in numerous human diseases(1). During pilus assembly, an outer membrane macromolecular machine called the usher catalyses pilus biogenesis from the individual subunits that are delivered as chaperone-subunit complexes in the periplasm. The usher orchestrates pilus assembly using all five functional domains: a 24-stranded transmembrane beta-barrel translocation domain, a beta-sandwich plug domain, an amino-terminal periplasmic domain and two carboxy-terminal periplasmic domains (CTD1 and CTD2)(2-6). Despite extensive structural and functional characterization, the mechanism by which the usher is activated to initiate pilus biogenesis is unknown. Here, we present the crystal structure of the full-length PapC usher from Escherichia coli in complex with its cognate PapDG chaperone-subunit complex in a pre-activation state, elucidating molecular details of how the usher is specifically engaged by allosteric interactions with its substrate preceding activation and how the usher facilitates the transfer of subunits from the amino-terminal periplasmic domain to the CTDs during pilus assembly. This work elucidates the intricate workings of a molecular machine that catalyses chaperone-usher pathway pilus assembly and opens the door for the development of potent inhibitors to block pilus biogenesis.
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| 12. |
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| 13. |
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| 14. |
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| 15. |
- Adolfsson, Per I., et al.
(författare)
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Characterization of EDG receptor expression and proliferative response in cultured human BPH smooth muscle cells
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The endogenous phospholipids, lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P) are both known to generate a Vvide variety of effects in various cell systems by the endothelial differentiation gene (Edg) receptor family, including 7 different G-protein coupled Edg receptors.In this study, expression of LPA- and SlP Edg receptors was examined, and so was the effect with respect to proliferation on cultured BPH smooth muscle cells smc. Mmeover, theresponse on cAMP levels was examined. Finally, a potential link between activation of the MAP kinase cascade and the LPA stimulated proliferation was investigated.First, the RT-PCR analysis of the Edg receptors in BPH smc, demonstrated a heterogeneous expression including all receptors except the Edg6 subtype. Further, in contrast to LPA, the mitogen effect of SIP, demonstrated a concentration-dependent biphasic response, including stimulation below 1μM, whereas inhibition was obtained at higher concentrations. Forskolin induced a rapid and transient cAMP response in LPA stimulated cells, with a peak-value after 3 minutes. After 15 minutes the cAMP level had retmned to base-line level. However a gradual increase to 15% of maximum value was obtained after additional 30 minutes, and thereafter a gradual reduction was observed. The mentioned antiproliferative response generated by SIP could not be conelated to an intracellular cAMP increase. Finally, when the LPA treated smc was co-incubated with the MAPK kinase inhibitor PD98059 (10 μM) the mitogen response was eliminated.The cAIVIP increase, which was induced by forskolin, corresponds with mentioned antiproliferative effect whereas a similar con-elation was not obtained regarding SIP. The intracellular signal mechanisms triggered by LPA and S1P in BPH smc remain to be further investigated.
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| 16. |
- Ambite, Ines, et al.
(författare)
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Fimbriae reprogram host gene expression - Divergent effects of P and type 1 fimbriae
- 2019
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Ingår i: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 15:6, s. 1007671-1007671
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Tidskriftsartikel (refereegranskat)abstract
- Pathogens rely on a complex virulence gene repertoire to successfully attack their hosts. We were therefore surprised to find that a single fimbrial gene reconstitution can return the virulence-attenuated commensal strain Escherichia coli 83972 to virulence, defined by a disease phenotype in human hosts. E. coli 83972pap stably reprogrammed host gene expression, by activating an acute pyelonephritis-associated, IRF7-dependent gene network. The PapG protein was internalized by human kidney cells and served as a transcriptional agonist of IRF-7, IFN-β and MYC, suggesting direct involvement of the fimbrial adhesin in this process. IRF-7 was further identified as a potent upstream regulator (-log (p-value) = 61), consistent with the effects in inoculated patients. In contrast, E. coli 83972fim transiently attenuated overall gene expression in human hosts, enhancing the effects of E. coli 83972. The inhibition of RNA processing and ribosomal assembly indicated a homeostatic rather than a pathogenic end-point. In parallel, the expression of specific ion channels and neuropeptide gene networks was transiently enhanced, in a FimH-dependent manner. The studies were performed to establish protective asymptomatic bacteriuria in human hosts and the reconstituted E. coli 83972 variants were developed to improve bacterial fitness for the human urinary tract. Unexpectedly, P fimbriae were able to drive a disease response, suggesting that like oncogene addiction in cancer, pathogens may be addicted to single super-virulence factors.
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| 17. |
- Andersson, Jan, et al.
(författare)
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Traffic safety effects when overtaking 30 meter trucks
- 2012
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Ingår i: Advances in Human Factors and Ergonomics 2012- 14 Volume Set. - : Taylor & Francis. - 146655262X - 9781466552623
-
Konferensbidrag (refereegranskat)abstract
- The purpose of this paper is to investigate if the introduction of extra-long and heavy trucks has an effect on traffic safety on Swedish roads, especially in relation to overtaking maneuvers. Traffic safety effects will be measured in terms of road user behavior concerning accelerations and time slots. First, focus group interviews with heavy truck drivers. Truck drivers that do not drive extra-long trucks believe that the introduction of extra-long trucks will create a number of traffic safety problems especially in terms of conflicts with ordinary road users. The drivers of extra-long trucks do not experience the problems that ordinary truck drivers predict. The problems they experience can be taken care of with more planning (thinking ahead). They also believe that the traffic sign on the back of the extra-long vehicle has a positive effect. The truck company, working environment and truck equipment are other important aspects mentioned by the drivers of the extra-long vehicles.The simulator study investigates overtaking situations on a 2+1-lane highway, with extra-long trucks (30.4 m) and ordinary trucks (18.75 m). The results reveal that the distance from the rear/front of the truck to the point where only one lane exists affects car drivers’ decision to overtake, independently of truck length. If the truck is in the relatively same position, the timeslot for a safe overtaking maneuver before next one-lane section was reduced significantly for extra-long trucks compared to ordinary trucks. The conclusion is that there exist small tendencies which point in the direction of enhanced traffic safety problems with the introduction of extra-long trucks. The results should, however, be interpreted with caution as the number of data points was few and collected in specific situations and in specific conditions. It was neither considered how the introduction of longer and heavier trucks, given a constant amount of goods, reduces the number of heavy trucks on the road network.
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| 18. |
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| 19. |
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| 20. |
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| 21. |
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| 22. |
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| 23. |
- 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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| 24. |
- Chorell, Erik, et al.
(författare)
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Design and Synthesis of Fluorescent Pilicides and Curlicides : Bioactive Tools to Study Bacterial Virulence Mechanisms
- 2012
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Ingår i: Chemistry - A European Journal. - Berlin : Wiley-VCH Verlagsgesellschaft. - 0947-6539 .- 1521-3765. ; 18:15, s. 4522-4532
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Tidskriftsartikel (refereegranskat)abstract
- Pilicides and curlicides are compounds that block the formation of the virulence factors pili and curli, respectively. To facilitate studies of the interaction between these compounds and the pili and curli assembly systems, fluorescent pilicides and curlicides have been synthesized. This was achieved by using a strategy based on structure-activity knowledge, in which key pilicide and curlicide substituents on the ring-fused dihydrothiazolo 2-pyridone central fragment were replaced by fluorophores. Several of the resulting fluorescent compounds had improved activities as measured in pili- and curli-dependent biofilm assays. We created fluorescent pilicides and curlicides by introducing coumarin and 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) fluorophores at two positions on the peptidomimetic pilicide and curlicide central fragment. Fluorescence images of the uropathogenic Escherichia coli (UPEC) strain UTI89 grown in the presence of these compounds shows that the compounds are strongly associated with the bacteria with a heterogeneous distribution.
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| 25. |
- Chorell, Erik, 1980-, et al.
(författare)
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Design and synthesis of fluorescently labeled pilicides and curlicides: bioactive tools to study bacterial virulence mechanisms
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Pilicides and curlicides block formation of the E. coli virulence factors pili and curli. To facilitate studies of the interaction between these compounds and the pili and curli assembly systems, fluorescent pilicides and curlicides have been synthesized. This was achieved using a strategy where key pilicide and curlicide substituents were replaced by fluorophores having similar physicochemical properties. The resulting fluorescent compounds had improved anti-virulence activities as measured in pili- and curli-dependent biofilm assays. We created fluorescent pilicides and curlicides by introducing both coumarin and 4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) fluorophores at two positions on the peptidomimetic pilicide and curlicide scaffold. Fluorescence images of the uropathogenic Escherichia coli (UPEC) strain UTI89 grown in the presence of these compounds shows that the compounds are strongly associated to the bacteria and seem to discriminate between different bacteria in a population.
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| 26. |
- Chorell, Erik, et al.
(författare)
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Mapping pilicide anti-virulence effect in Escherichia coli, a comprehensive structure-activity study
- 2012
-
Ingår i: Bioorganic & Medicinal Chemistry. - : Elsevier. - 0968-0896 .- 1464-3391. ; 20:9, s. 3128-3142
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Tidskriftsartikel (refereegranskat)abstract
- Pilicides prevent pili formation and thereby the development of bacterial biofilms in Escherichia coli. We have performed a comprehensive structure activity relationship (SAR) study of the dihydrothiazolo ring-fused 2-pyridone pilicide central fragment by varying all open positions. Orthogonal projections to latent structures discriminant analysis (OPLS-DA) was used to distinguish active from inactive compounds in which polarity proved to be the most important factor for discrimination. A quantitative SAR (QSAR) partial least squares (PLS) model was calculated on the active compounds for prediction of biofilm inhibition activity. In this model, compounds with high inhibitory activity were generally larger, more lipophilic, more flexible and had a lower HOMO. Overall, this resulted in both highly valuable SAR information and potent inhibitors of type 1 pili dependent biofilm formation. The most potent biofilm inhibitor had an EC(50) of 400nM.
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| 27. |
- Chorell, Erik, et al.
(författare)
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Synthesis and application of a bromomethyl substituted scaffold to be used for efficient optimization of anti-virulence activity
- 2011
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Ingår i: European Journal of Medicinal Chemistry. - : Elsevier Masson SAS. - 0223-5234 .- 1768-3254. ; 46:4, s. 1103-1116
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Tidskriftsartikel (refereegranskat)abstract
- Pilicides are a class of compounds that attenuate virulence in Gram negative bacteria by blocking the chaperone/usher pathway in Escherichia coli. It has also been shown that compounds derived from the peptidomimetic scaffold that the pilicides are based on can prevent both Aβ aggregation and curli formation. To facilitate optimizations towards the different targets, a new synthetic platform has been developed that enables fast and simple introduction of various substituents in position C-7 on the peptidomimetic scaffold. Importantly, this strategy also enables introduction of previously unattainable heteroatoms in this position. Pivotal to the synthetic strategy is the synthesis of a C-7 bromomethyl substituted derivative of the ring-fused dihydrothiazolo 2-pyridone pilicide scaffold. From this versatile and reactive intermediate various heteroatom-linked substituents could be introduced on the scaffold including amines, ethers, amides and sulfonamides. In addition, carbon-carbon bonds could be introduced to the sp(3)-hybridized bromomethyl substituted scaffold by Suzuki-Miyaura cross couplings. Evaluation of the 24 C-7 substituted compounds in whole-bacterial assays provided important structure-activity data and resulted in the identification of a number of new pilicides with activity as good or better than those developed previously.
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| 28. |
- Dang, Hung The, et al.
(författare)
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Syntheses and biological evaluation of 2-amino-3-acyl-tetrahydrobenzothiophene derivatives : antibacterial agents with antivirulence activity
- 2014
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Ingår i: Organic and biomolecular chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 12:12, s. 1942-1956
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Tidskriftsartikel (refereegranskat)abstract
- Developing new compounds targeting virulence factors (e.g., inhibition of pilus assembly by pilicides) is a promising approach to combating bacterial infection. A high-throughput screening campaign of a library of 17 500 small molecules identified 2-amino-3-acyl-tetrahydrobenzothiophene derivatives (hits 2 and 3) as novel inhibitors of pili-dependent biofilm formation in a uropathogenic Escherichia coli strain UTI89. Based on compounds 2 and 3 as the starting point, we designed and synthesized a series of structurally related analogs and investigated their activity against biofilm formation of E. coli UTI89. Systematic structural modification of the initial hits provided valuable information on their SARs for further optimization. In addition, small structural changes to the parent molecules resulted in low micromolar inhibitors (20-23) of E. coli biofilm development without an effect on bacterial growth. The hit compound 3 and its analog 20 were confirmed to prevent pili formation in a hemagglutination (HA) titer assay and electron microscopy (EM) measurements. These findings suggest that 2-amino-3-acyl-tetrahydrobenzothiophenes may serve as a new class of compounds for further elaboration as antibacterial agents with antivirulence activity.
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| 29. |
- D'Oria, M, et al.
(författare)
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The "Vascular Surgery COVID-19 Collaborative" (VASCC)
- 2020
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Ingår i: European journal of vascular and endovascular surgery : the official journal of the European Society for Vascular Surgery. - : Elsevier BV. - 1532-2165. ; 60:3, s. 489-490
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 30. |
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| 31. |
- Emtenäs, Hans, et al.
(författare)
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Design and Parallel Solid Phase Synthesis of Ring Fused 2-Pyridinones that Target Pilus Biogenesis in Pathogenic Bacteria
- 2002
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Ingår i: Journal of Combinatorial Chemistry. - : American Chemical Society (ACS). - 1520-4766 .- 1520-4774. ; 4, s. 630-639
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Tidskriftsartikel (refereegranskat)abstract
- A new method for the solid-phase synthesis of enantiomerically enriched highly substituted ring-fused 2-pyridinones 13 has been developed. The synthesis mediates introduction of substituents at two positions in the 2-pyridinone ring in a diverse manner and is suitable for parallel synthesis. 19F NMR spectroscopy was used as a tool to monitor each of the five steps in the reaction sequence. The optimized conditions thus obtained were then used to prepare a library of 20 2-pyridinones with high yields. The library members were chosen from a statistical multivariate design to ensure diversity and reliable data for structure−activity relationships. Screening of the library against the bacterial periplasmic chaperone PapD was performed using surface plasmon resonance. Three new 2-pyridinones with a higher affinity for the chaperone PapD than the previous best 13{10,1} were found, and important structural features could be deduced.
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| 32. |
- Emtenäs, Hans, et al.
(författare)
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Stereoselective synthesis of optically active bicyclic -lactam carboxylic acids that target pilus biogenesis in pathogenic bacteria
- 2003
-
Ingår i: Organic & Biomolecular Chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 1, s. 1308-14
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Tidskriftsartikel (refereegranskat)abstract
- Optically active bicyclic -lactams were synthesized, starting from 2-H-2-thiazolines and Meldrum's acid derivatives. Several methods to accomplish an ester hydrolysis without damaging the -lactam framework were investigated. A rapid CsOH saponification of the -lactam methyl esters was developed and protonation of the Cs-carboxylates by Amberlite (IR-120 H+) afforded a series of bicyclic -lactam carboxylic acids. Moreover, a convenient method for the synthesis of 2-H-2-thiazolinecarboxylic acid methyl ester 2 was developed. Bicyclic -lactam carboxylic acids 7a–g and aldehydes 4a–d were screened for their affinity to the bacterial periplasmic chaperone PapD using a surface plasmon resonance technique. -Lactams substituted with large acyl substituents showed better binding to the chaperone than the native C-terminal peptide PapG 8, demonstrating that bicyclic -lactams constitute a new class of potential bacterial chaperone inhibitors.
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| 33. |
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| 34. |
- Fredin, Maria Fritsch, 1970, et al.
(författare)
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Dextran sulfate sodium-induced colitis generates a transient thymic involution--impact on thymocyte subsets.
- 2007
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Ingår i: Scandinavian journal of immunology. - : Wiley. - 0300-9475 .- 1365-3083. ; 65:5, s. 421-9
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Tidskriftsartikel (refereegranskat)abstract
- One of the most widely used animal models for inflammatory bowel disease (IBD) is the dextran sulfate sodium (DSS)-induced colitis. We have previously reported that 5 days administration of DSS in C57Bl/6J mice induces a colonic inflammation that progresses into chronicity after DSS removal, whereas in BALB/cJ mice the inflammation resolves within 4 weeks post-DSS. Here we show that both thymic size and thymocyte numbers dramatically decreased in the acute phase of inflammation in C57Bl/6 mice, 7 days after DSS withdrawal. Mature, CD4(+) and CD8(+) single positive (SP) CD69(lo) CD62L(hi) thymocytes were enriched in these mice, accompanied by a major decrease in the number of immature double positive (DP) thymocytes. However, the different maturation stages within the DP thymocyte subset were unchanged between healthy and inflamed C57Bl/6J mice. Interestingly, as the inflammation progressed into the chronic phase, the thymus recovered and 2 weeks after the acute inflammatory phase all the thymic parameters investigated in this study were restored to normal. In contrast, BALB/cJ mice only develop mild thymic alterations. Nevertheless, we found that within the double negative (DN) thymocytes an increased frequency and also total numbers of CD44(+) CD25(-) (DN1) cells correlated with the severity of colitis, and that the frequency of CD44(-) CD25(-) (DN4) thymocytes decreased proportionally in the acute phase in BALB/cJ mice. Our observations suggest that the thymic effects are intimately connected to the intestinal inflammatory response in colitis regardless of the inflammatory stimuli.
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| 35. |
- Gjertsson, Inger, 1962, et al.
(författare)
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Impact of transcription factors AP-1 and NF-kappaB on the outcome of experimental Staphylococcus aureus arthritis and sepsis.
- 2001
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Ingår i: Microbes and infection. - 1286-4579. ; 3:7, s. 527-34
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Tidskriftsartikel (refereegranskat)abstract
- Staphylococcus aureus infection is, despite adequate antibiotic treatment, a disease characterized by high mortality. The bacterium triggers an exaggerated immune response in the host, which on the one hand acts as an efficient defense, but on the other hand gives rise to tissue damage. In this study we have modulated the hosts response to S. aureus by inhibition of nuclear factor kappaB (NF-kappaB) and activator protein-1 (AP-1)-triggered release of pro-inflammatory cytokines and tissue-destructive proteins, respectively. Mice were administered with antisense oligonucleotides (ODN) to the p65 subunit of NF-kappaB and/or a double-stranded oligonucleotide (mCoAP-1) with homology to the murine AP-1 binding site of collagenase IV gene (metalloproteinase-9; MMP-9), solely or in combination with antibiotics. In mice systemically treated with antisense ODN to NF-kappaB p65 alone, the bacterial burden in the kidneys was significantly increased (P = 0.04) The same tendency was seen when mCoAP-1 was administered either alone or in combination with antibiotics. We also found significantly (P = 0.04) elevated levels of IL-6 in p65 antisense treated mice. Surprisingly, this p65 antisense therapy approach, which has turned out to be highly efficient in amelioration of aseptic arthritis and colitis, failed to change the clinical course of either septic arthritis or sepsis. We suggest that interaction with transcription factors leads to increased bacterial burden in vivo, abrogating the potential benefits of the anti-inflammatory properties exerted by these compounds.
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| 36. |
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| 37. |
- Göranzon, C., et al.
(författare)
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Immunohistochemical characterization of lymphocytes in microscopic colitis
- 2013
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Ingår i: Journal of Crohn's and Colitis. - : Elsevier. - 1197-4982 .- 1873-9946. ; 7:10, s. e434-e442
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Tidskriftsartikel (refereegranskat)abstract
- Background and Aims: Microscopic colitis (MC), encompassing the subgroups collagenous colitis (CC) and lymphocytic colitis (LC), is characterized by macroscopically normal or near-normal colonic mucosa, and an increased number of intraepithelial lymphocytes (IELs) and mononuclear cell infiltration in the underlying lamina propria (LP), in addition to an increased collagen layer in CC. This study aimed to characterize the inflammatory cells involved in mucosal inflammation, using immunohistochemistry.Methods Paraffin-embedded biopsies from 23 untreated patients with MC (CC = 13, LC = 10) and 17 controls were stained with antibodies against CD3, CD4, CD8, CD20, CD30, Foxp3, CD45RO and Ki67. Computerized image analysis was used to calculate areas of stained lymphocytes in the surface and crypt epithelia as well as in the LP.Results In CC and LC, an increase of predominantly CD8+ lymphocytes was seen in both the epithelium and the lamina propria, whereas a decreased amount of CD4+ lymphocytes was found in the lamina propria. CD45RO+ and Foxp3+ cells were more abundant in all areas in both patient groups compared to controls, as were CD20+ areas, although more scarce. Ki67+ areas were only more abundant in the epithelium, whereas CD30+ areas were more abundant in the lamina propria of both patient groups compared to controls.Conclusions This study confirms an increased amount of CD8+ lymphocytes in the epithelium. Lymphocytic proliferation and activation markers were more abundant, whereas a decreased amount of CD4+ lymphocytes was seen in the LP. Further studies are needed to reveal the underlying mechanism(s).
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| 38. |
- 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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| 39. |
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| 40. |
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| 41. |
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| 42. |
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| 43. |
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| 44. |
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| 45. |
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| 46. |
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| 47. |
- Klinth, Jeanna E, et al.
(författare)
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Impairment of the biomechanical compliance of P pili : a novel means of inhibiting uropathogenic bacterial infections?
- 2012
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Ingår i: European Biophysics Journal. - Berlin : Springer. - 0175-7571 .- 1432-1017. ; 41:3, s. 285-295
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Tidskriftsartikel (refereegranskat)abstract
- Gram-negative bacteria often initiate their colonization by use of extended attachment organelles, so called pili. When exposed to force, the rod of helix-like pili has been found to be highly extendable, mainly attributed to uncoiling and recoiling of its quaternary structure. This provides the bacteria with the ability to redistribute an external force among a multitude of pili, which enables them to withstand strong rinsing flows, which, in turn, facilitates adherence and colonization processes critical to virulence. Thus, pili fibers are possible targets for novel antibacterial agents. By use of a substance that compromises compliance of the pili, the ability of bacteria to redistribute external forces can be impaired, so they will no longer be able to resist strong urine flow and thus be removed from the host. It is possible such a substance can serve as an alternative to existing antibiotics in the future or be a part of a multi-drug. In this work we investigated whether it is possible to achieve this by targeting the recoiling process. The test substance was purified PapD. The effect of PapD on the compliance of P pili was assessed at the single organelle level by use of force-measuring optical tweezers. We showed that the recoiling process, and thus the biomechanical compliance, in particular the recoiling process, can be impaired by the presence of PapD. This leads to a new concept in the search for novel drug candidates combating uropathogenic bacterial infections-"coilicides", targeting the subunits of which the pilus rod is composed.
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| 48. |
- 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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| 49. |
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| 50. |
- Larsson, Andreas, et al.
(författare)
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Quantitative studies of the binding of the class II PapG adhesin from uropathogenic Escherichia coli to oligosaccharides.
- 2003
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Ingår i: Bioorganic & Medicinal Chemistry. - : Elsevier. - 0968-0896 .- 1464-3391. ; 11:10, s. 2255-2261
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Tidskriftsartikel (refereegranskat)abstract
- Binding of the class II PapG adhesin, found at the tip of filamentous pili on Escherichia coli, to the carbohydrate moiety of globoseries glycolipids in the human kidney is a key step in development of pyelonephritis, a severe form of urinary tract infection. An assay based on surface plasmon resonance for quantification of the binding of the class II PapG adhesin to oligosaccharides has been developed. Using this assay dissociation constants ranging from 80 to 540 M were determined for binding of the PapG adhesin to di-pentasaccharide fragments from the globoseries of glycolipids. A series of galabiose derivatives, modified at the anomeric position, O-2′ or O-3′, was also investigated. The anomeric position appeared to be the most promising for development of improved inhibitors of PapG-mediated adhesion of E. coli. p-Methoxyphenyl galabioside was found to be most potent (Kd=140 M), and binds to PapG almost as well as the Forssman pentasaccharide.
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