| 1. |
- Chorell, Erik, 1980-, et al.
(författare)
-
Design and synthesis of C-2 substituted Thiazolo and Dihydrothiazolo ring-fused 2-Pyridones : pilicides with increased antivirulence activity
- 2010
-
Ingår i: Journal of Medicinal Chemistry. - Washington, USA : American Chemical Society. - 0022-2623 .- 1520-4804. ; 53:15, s. 5690-5695
-
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.
|
|
| 2. |
- Chorell, Erik, et al.
(författare)
-
Design and Synthesis of Fluorescent Pilicides and Curlicides : Bioactive Tools to Study Bacterial Virulence Mechanisms
- 2012
-
Ingår i: Chemistry - A European Journal. - Berlin : Wiley-VCH Verlagsgesellschaft. - 0947-6539 .- 1521-3765. ; 18:15, s. 4522-4532
-
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.
|
|
| 3. |
- Chorell, Erik, et al.
(författare)
-
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
-
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.
|
|
| 4. |
- Chorell, Erik, et al.
(författare)
-
Synthesis and application of a bromomethyl substituted scaffold to be used for efficient optimization of anti-virulence activity
- 2011
-
Ingår i: European Journal of Medicinal Chemistry. - : Elsevier Masson SAS. - 0223-5234 .- 1768-3254. ; 46:4, s. 1103-1116
-
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.
|
|
| 5. |
- Dang, Hung The, et al.
(författare)
-
Syntheses and biological evaluation of 2-amino-3-acyl-tetrahydrobenzothiophene derivatives : antibacterial agents with antivirulence activity
- 2014
-
Ingår i: Organic and biomolecular chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 12:12, s. 1942-1956
-
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.
|
|
| 6. |
- Greene, Sarah E., et al.
(författare)
-
Pilicide ec240 Disrupts Virulence Circuits in Uropathogenic Escherichia coli
- 2014
-
Ingår i: mBio. - 2161-2129 .- 2150-7511. ; 5:6, s. UNSP e02038-
-
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.
|
|
| 7. |
- Klinth, Jeanna E, et al.
(författare)
-
Impairment of the biomechanical compliance of P pili : a novel means of inhibiting uropathogenic bacterial infections?
- 2012
-
Ingår i: European Biophysics Journal. - Berlin : Springer. - 0175-7571 .- 1432-1017. ; 41:3, s. 285-295
-
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.
|
|
