| 1. |
- Andersson, C. David, 1978-, et al.
(författare)
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Influence of Enantiomeric Inhibitors on the Dynamics of Acetylcholinesterase Measured by Elastic Incoherent Neutron Scattering
- 2018
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 122:36, s. 8516-8525
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Tidskriftsartikel (refereegranskat)abstract
- The enzyme acetylcholinesterase (AChE) is essential in humans and animals because it catalyzes the breakdown of the nerve-signaling substance acetylcholine. Small molecules that inhibit the function of AChE are important for their use as drugs in the, for example, symptomatic treatment of Alzheimer's disease. New and improved inhibitors are warranted, mainly because of severe side effects of current drugs. In the present study, we have investigated if and how two enantiomeric inhibitors of AChE influence the overall dynamics of noncovalent complexes, using elastic incoherent neutron scattering. A fruitful combination of univariate models, including a newly developed non-Gaussian model for atomic fluctuations, and multivariate methods (principal component analysis and discriminant analysis) was crucial to analyze the fine details of the data. The study revealed a small but clear increase in the dynamics of the inhibited enzyme compared to that of the noninhibited enzyme and contributed to the fundamental knowledge of the mechanisms of AChE-inhibitor binding valuable for the future development of inhibitors.
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| 2. |
- Knutsson, Sofie, et al.
(författare)
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Noncovalent Inhibitors of Mosquito Acetylcholinesterase 1 with Resistance-Breaking Potency
- 2018
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 61:23, s. 10545-10557
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Tidskriftsartikel (refereegranskat)abstract
- Resistance development in insects significantly threatens the important benefits obtained by insecticide usage in vector control of disease-transmitting insects. Discovery of new chemical entities with insecticidal activity is highly desired in order to develop new insecticide candidates. Here, we present the design, synthesis, and biological evaluation of phenoxyacetamide-based inhibitors of the essential enzyme acetylcholinesterase 1 (AChE1). AChE1 is a validated insecticide target to control mosquito vectors of, e.g., malaria, dengue, and Zika virus infections. The inhibitors combine a mosquito versus human AChE selectivity with a high potency also for the resistance-conferring mutation G122S; two properties that have proven challenging to combine in a single compound. Structure activity relationship analyses and molecular dynamics simulations of inhibitor protein complexes have provided insights that elucidate the molecular basis for these properties. We also show that the inhibitors demonstrate in vivo insecticidal activity on disease-transmitting mosquitoes. Our findings support the concept of noncovalent, selective, and resistance-breaking inhibitors of AChE1 as a promising approach for future insecticide development.
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| 3. |
- Kulén, Martina, 1988-
(författare)
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New alternatives to combat Listeria monocytogenes and Chlamydia trachomatis : Design, synthesis, and evaluation of substituted ring-fused 2-pyridones as anti-virulent agents
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Antibiotic resistance has become a global health burden with the number of resistant bacteria continuously increasing. Antibiotic drugs act by being either bactericidal (killing bacteria) or bacteriostatic (inhibiting growth of bacteria). However, these modes of action increase the selective pressure on the bacteria. An alternative treatment strategy to antibiotics is anti-virulence therapies that inhibits virulence of the pathogenic bacteria. The term “virulence” summarises a number of factors that the bacteria need to colonise a new niche and as a consequence its ability to infect and cause diseases. By inhibiting virulence, instead of killing, the selective pressure on the bacteria can be reduced and consequently decreases the rapid development of resistance. This thesis describes two projects focusing on development of anti-virulence agents, with the ring-fused 2-pyridone scaffold as the central character, targeting the bacteria Listeria monocytogenes and Chlamydia trachomatis.The first project is targeting L. monocytogenes, which is the cause for listeriosis in humans. This can develop into life-threatening encephalitis and meningitis as well as cause severe complications for developing fetus. The target in L. monocytogenes is the transcriptional regulator PrfA that control almost all virulence factors in this bacterium. We have designed and synthesised potent substituted ring-fused 2-pyridones, which at low micromolar concentrations block activation of the virulence regulator PrfA and thus attenuate the bacterial infection. Co-crystallisation of the active ring-fused 2-pyridones with PrfA resulted in determination of the exact substance interaction site in the protein. This facilitated further structure-based design that resulted in improved compounds capable of attenuating L. monocytogenes in an in vivo model.The second project targets C. trachomatis, which is the causative agent behind the most common sexually transmitted infection as well as the eye infection trachoma. By structure-activity relationship analysis of previously tested ring-fused 2-pyridones, we have designed and synthesised non-hydrolysable ring-fused 2-pyridone amide isosteres. The most potent analogues inhibit C. trachomatis infectivity at low nanomolar concentrations, without showing host cell toxicity or affecting the viability of commensal microbiota. Introduction of heteroatom substituents at specific sites of the ring-fused 2-pyridone scaffold, resulted in improved pharmacokinetic properties of the analogues and further evaluation in vivo was performed.
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| 4. |
- Lindgren, Cecilia, et al.
(författare)
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Dynamics Determine Signaling in a Multicomponent System Associated with Rheumatoid Arthritis
- 2018
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 61:11, s. 4774-4790
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Tidskriftsartikel (refereegranskat)abstract
- Strategies that target multiple components are usually required for treatment of diseases originating from complex biological systems. The multicomponent system consisting of the DR4 major histocompatibility complex type II molecule, the glycopeptide CI1259-273 from type II collagen, and a T-cell receptor is associated with development of rheumatoid arthritis (RA). We introduced non-native amino acids and amide bond isosteres into CI1259-273 and investigated the effect on binding to DR4 and the subsequent T-cell response. Molecular dynamics simulations revealed that complexes between DR4 and derivatives of CI1259-273 were highly dynamic. Signaling in the overall multicomponent system was found to depend on formation of an appropriate number of dynamic intramolecular hydrogen bonds between DR4 and CI1259-273, together with the positioning of the galactose moiety of CI1259-273 in the DR4 binding groove. Interestingly, the system tolerated modifications at several positions in CI1259-273, indicating opportunities to use analogues to increase our understanding of how rheumatoid arthritis develops and for evaluation as vaccines to treat RA.
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| 5. |
- Rogne, Per, et al.
(författare)
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Nucleation of an Activating Conformational Change by a Cation−Π Interaction
- 2019
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Ingår i: Biochemistry. - : American Chemical Society (ACS). - 0006-2960 .- 1520-4995. ; 58:32, s. 3408-3412
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Tidskriftsartikel (refereegranskat)abstract
- As a key molecule in biology, adenosine triphosphate (ATP) has numerous crucial functions in, for instance, energetics, post-translational modifications, nucleotide biosynthesis, and cofactor metabolism. Here, we have discovered an intricate interplay between the enzyme adenylate kinase and its substrate ATP. The side chain of an arginine residue was found to be an efficient sensor of the aromatic moiety of ATP through the formation of a strong cation−π interaction. In addition to recognition, the interaction was found to have dual functionality. First, it nucleates the activating conformational transition of the ATP binding domain and also affects the specificity in the distant AMP binding domain. In light of the functional consequences resulting from the cation−π interaction, it is possible that the mode of ATP recognition may be a useful tool in enzyme design.
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| 6. |
- Veenaas, Cathrin, et al.
(författare)
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Retention-time prediction in comprehensive two-dimensional gas chromatography to aid identification of unknown contaminants
- 2018
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Berlin/Heidelberg. - 1618-2642 .- 1618-2650. ; 410:30, s. 7931-7941
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Tidskriftsartikel (refereegranskat)abstract
- Comprehensive two-dimensional (2D) gas chromatography (GC×GC) coupled to mass spectrometry (MS, GC×GC-MS), which enhances selectivity compared to GC-MS analysis, can be used for non-directed analysis (non-target screening) of environmental samples. Additional tools that aid in identifying unknown compounds are needed to handle the large amount of data generated. These tools include retention indices for characterizing relative retention of compounds and prediction of such. In this study, two quantitative structure–retention relationship (QSRR) approaches for prediction of retention times (1tR and 2tR) and indices (linear retention indices (LRIs) and a new polyethylene glycol–based retention index (PEG-2I)) in GC × GC were explored, and their predictive power compared. In the first method, molecular descriptors combined with partial least squares (PLS) analysis were used to predict times and indices. In the second method, the commercial software package ChromGenius (ACD/Labs), based on a “federation of local models,” was employed. Overall, the PLS approach exhibited better accuracy than the ChromGenius approach. Although average errors for the LRI prediction via ChromGenius were slightly lower, PLS was superior in all other cases. The average deviations between the predicted and the experimental value were 5% and 3% for the 1tR and LRI, and 5% and 12% for the 2tR and PEG-2I, respectively. These results are comparable to or better than those reported in previous studies. Finally, the developed model was successfully applied to an independent dataset and led to the discovery of 12 wrongly assigned compounds. The results of the present work represent the first-ever prediction of the PEG-2I.
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