| 1. |
- Kauppi, Anna M., 1971-, et al.
(författare)
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Inhibitors of type III secretion in Yersinia : design, synthesis and multivariate QSAR of 2-sulfonamino-benzanilides
- 2007
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Ingår i: Bioorganic & Medicinal Chemistry. - : Elsevier Ltd. - 0968-0896 .- 1464-3391. ; 15:22, s. 6994-7011
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Compound 1, 2-(benzo[1,2,5]thiadiazole-4-sulfonylamino)-5-chloro-N-(3,4-dichloro-phenyl)-benzamide, was identified as a putative type III secretion inhibitor in Yersinia, and the compound thus has a potential to be used to prevent or treat bacterial infections. A set of seven analogues was synthesized and evaluated in a type III secretion dependent reporter-gene assay with viable bacterial to give basic SAR. A second set of 19 compounds was obtained by statistical molecular design in the building block and product space and subsequent synthesis. Evaluation in the reporter-gene assay showed that the compounds ranged from non-active to compounds more potent than 1. Based on the data multivariate QSAR models were established and the final Hi-PLS model showed good correlation between experimentally determined % inhibition and the calculated % inhibition of the reporter-gene signal.
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| 2. |
- Andersson, David C., 1978-, et al.
(författare)
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A multivariate approach to investigate docking parameters' effects on docking performance
- 2007
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Ingår i: Journal of chemical information and modeling. - : American Chemical Society Publications. - 1549-9596 .- 1549-960X. ; 47:4, s. 1673-1687
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Tidskriftsartikel (refereegranskat)abstract
- Increasingly powerful docking programs for analyzing and estimating the strength of protein-ligand interactions have been developed in recent decades, and they are now valuable tools in drug discovery. Software used to perform dockings relies on a number of parameters that affect various steps in the docking procedure. However, identifying the best choices of the settings for these parameters is often challenging. Therefore, the settings of the parameters are quite often left at their default values, even though scientists with long experience with a specific docking tool know that modifying certain parameters can improve the results. In the study presented here, we have used statistical experimental design and subsequent regression based on root-mean-square deviation values using partial least-square projections to latent structures (PLS) to scrutinize the effects of different parameters on the docking performance of two software packages: FRED and GOLD. Protein-ligand complexes with a high level of ligand diversity were selected from the PDBbind database for the study, using principal component analysis based on 1D and 2D descriptors, and space-filling design. The PLS models showed quantitative relationships between the docking parameters and the ability of the programs to reproduce the ligand crystallographic conformation. The PLS models also revealed which of the parameters and what parameter settings were important for the docking performance of the two programs. Furthermore, the variation in docking results obtained with specific parameter settings for different protein-ligand complexes in the diverse set examined indicates that there is great potential for optimizing the parameter settings for selected sets of proteins.
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| 3. |
- Andersson, David C., 1978-, et al.
(författare)
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Design of target-tailored virtual screening experiments
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Discovering molecules with a desired biological function is one of the great challenges in drug research. To discover new lead molecules, in silico virtual screens (VS) are often conducted, in which databases of molecules are screened for potential binders to a specific protein, using molecular docking. The choice of docking software and parameter settings within the software can significantly influence the outcome of a VS. In this study, we have applied chemometric methods such as DoE, principal component analysis (PCA) and partial least-square projections to latent structure (PLS) to simulated VS experiments to find and compare suitable conditions for performing VS against six protein targets selected from the DUD databases. The docking parameters in FRED, and scoring functions in both FRED and GOLD docking software, were varied according to a statistical experimental design and a PLS model was calculated to correlate the experimental setup to the VS outcome. The study revealed that the choice of scoring function has the greatest influence on VS outcome, and that other parameters have varying influence, depending on the protein target. We also found that substantial bias can be introduced by the lack of variation of molecule properties in the databases used in the screening. The results indicate that docking experiments should be tailored to the protein target in order to obtain satisfactory VS results and that our methodology provides a suitable approach for such tailoring.
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| 4. |
- Andersson, David C., 1978-, et al.
(författare)
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Mapping of ligand-binding cavities in proteins
- 2010
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Ingår i: Proteins. - : John Wiley & Sons, Inc. - 0887-3585 .- 1097-0134. ; 78:6, s. 1408-1422
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Tidskriftsartikel (refereegranskat)abstract
- The complex interactions between proteins and small organic molecules (ligands) are intensively studied because they play key roles in biological processes and drug activities. Here, we present a novel approach to characterize and map the ligand-binding cavities of proteins without direct geometric comparison of structures, based on Principal Component Analysis of cavity properties (related mainly to size, polarity, and charge). This approach can provide valuable information on the similarities and dissimilarities, of binding cavities due to mutations, between-species differences and flexibility upon ligand-binding. The presented results show that information on ligand-binding cavity variations can complement information on protein similarity obtained from sequence comparisons. The predictive aspect of the method is exemplified by successful predictions of serine proteases that were not included in the model construction. The presented strategy to compare ligand-binding cavities of related and unrelated proteins has many potential applications within protein and medicinal chemistry, for example in the characterization and mapping of "orphan structures", selection of protein structures for docking studies in structure-based design, and identification of proteins for selectivity screens in drug design programs.
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| 5. |
- Andréasson, Måns, 1994-
(författare)
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Redefining the essential molecular aspects that drive interactions between small molecules and G-quadruplex DNA
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- G-Quadruplex (G4) structures are secondary nucleic acid structures located in guanine-rich regions of DNA and RNA sequences, involved in gene regulation and cellular maintenance. Efforts to target G4s in a therapeutic setting are scarce, mainly due to vague details about the binding interactions between the ligands and the G4 structure combined with the lack of emphasis on drug-like properties early in the ligand development process. Furthermore, the ability to target specific G4 structures with small drug-like molecules remains a big challenge to overcome in the field. In this thesis, extensive organic synthesis developments coupled with computational-aided design and orthogonal in vitro assays has been used in tandem to reveal in-depth knowledge about ligand-to-G4 interactions. First, a macrocyclic approach was applied to design and discover novel G4 ligands which showed that macrocycles offer a solid foundation for ligand design. Next, computational tools to optimise the macrocyclic molecular conformation were used based on the macrocycles' abilities to stack on the G4 surface. In addition, macrocyclic, and non-macrocyclic ligands that bound G4 with high potency were shown to correlate with electron-deficient electrostatic potential (ESP) maps. The frequent inclusion of cationic residues in G4 ligands and their enhancement on ligand-to-G4 binding was, thereof, ascribed to their impact on the electrostatic character of the ligands' arene-arene interactions with the G4 surface, and not through direct electrostatic ionic interactions. In addition, the dispersion energetic component in the arene-arene interactions between the G4 ligand and the G4 was discovered to be paramount for ligand-to-G4 binding. The implementation of these descriptors in practice resulted in the discovery of potent G4 binders with adequate pharmacokinetic (PK) properties, accentuating the significance of understanding the molecular interactions between ligands and G4s in rational ligand design. Finally, a G4 ligand conjugated to an oligonucleotide was demonstrated as a modular approach to achieve selective binding of a ligand to a specific G4 structure.
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| 6. |
- 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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