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Illkirch, France

Hoffer L.,University of Strasbourg | Hoffer L.,Novalix Inc. | Horvath D.,University of Strasbourg
Journal of Chemical Information and Modeling

S4MPLE is a conformational sampling tool, based on a hybrid genetic algorithm, simulating one (conformer enumeration) or more molecules (docking). Energy calculations are based on the AMBER force field [ Cornell et al. J. Am. Chem. Soc. 1995, 117, 5179. ] for biological macromolecules and its generalized version GAFF [ Wang et al. J. Comput. Chem. 2004, 25, 1157. ] for ligands. This paper describes more advanced, specific applications of S4MPLE to problems more complex than classical redocking of drug-like compounds [ Hoffer et al. J. Mol. Graphics Modell. 2012, submitted for publication. ]. Here, simultaneous docking of multiple entities is addressed in two different important contexts. First, simultaneous docking of two fragment-like ligands was attempted, as such ternary complexes are the basis of fragment-based drug design by linkage of the independent binders. As a preliminary, the capacity of S4MPLE to dock fragment-like compounds has been assessed, since this class of small probes used in fragment-based drug design covers a different chemical space than drug-like molecules. Herein reported success rates from fragments redocking are as good as classical benchmarking results on drug-like compounds (Astex Diverse Set [ Hartshorn et al. J. Med. Chem. 2007, 50, 726. ]). Then, S4MPLE is successfully challenged to predict locations of fragments involved in ternary complexes by means of multientity docking. Second, the key problem of predicting water-mediated interaction is addressed by considering explicit water molecules as additional entities to be docked in the presence of the "main" ligand. Blind prediction of solvent molecule positions, reproducing relevant ligand-water-site mediated interactions, is achieved in 76% cases over saved poses. S4MPLE was also successful to predict crystallographic water displacement by a therefore tailored functional group in the optimized ligand. However, water localization is an extremely delicate issue in terms of weighing of electrostatic and desolvation terms and also introduces a significant increase of required sampling efforts. Yet, the herein reported results - not making use of massively parallel deployment of the software - are very encouraging. © 2012 American Chemical Society. Source

Ciesielski F.,University of Strasbourg | Ciesielski F.,Novalix Inc. | Sato Y.,University of Strasbourg | Sato Y.,Kyushu University | And 4 more authors.
Journal of Medicinal Chemistry

Actual use of the active form of vitamin D (calcitriol or 1α,25-dihydroxyvitamin D3) to treat hyperproliferative disorders is hampered by calcemic effects, hence the continuous development of chemically modified analogues with dissociated profiles. Structurally distinct nonsecosteroidal analogues have been developed to mimic calcitriol activity profiles with low calcium serum levels. Here, we report the crystallographic study of vitamin D nuclear receptor (VDR) ligand binding domain in complexes with six nonsecosteroidal analogues harboring two or three phenyl rings. These compounds induce a stimulated transcription in the nanomolar range, similar to calcitriol. Examination of the protein-ligand interactions reveals the mode of binding of these nonsecosteroidal compounds and highlights the role of the various chemical modifications of the ligands to VDR binding and activity, notably (de)solvation effects. The structures with the tris-aromatic ligands exhibit a rearrangement of a novel region of the VDR ligand binding pocket, helix H6. © 2012 American Chemical Society. Source

Huet T.,University of Strasbourg | Huet T.,Cbs Therapeutics, Inc. | Laverny G.,University of Strasbourg | Ciesielski F.,University of Strasbourg | And 11 more authors.
Cell Reports

The bioactive form of vitamin D [1,25(OH)2D3] regulates mineral and bone homeostasis and exerts potent anti-inflammatory and antiproliferative properties through binding to the vitamin D receptor (VDR). The 3D structures of the VDR ligand-binding domain with 1,25(OH)2D3 or gemini analogs unveiled the molecular mechanism underlying ligand recognition. On the basis of structure-function correlations, we generated a point-mutated VDR (VDRgem) that isunresponsive to 1,25(OH)2D3, but the activity of which is efficiently induced by the gemini ligands. Moreover, we show that many VDR target genes are repressed by unliganded VDRgem and that mineral ion and bone homeostasis are more impaired in VDRgem mice than in VDR null mice, demonstrating that mutations abolishing VDR ligand binding result in more severe skeletal defects than VDR null mutations. As gemini ligands induce VDRgem transcriptional activity in mice and normalize their serum calcium levels, VDRgem is a powerful tool to further unravel both liganded and unliganded VDR signaling. © 2015 The Authors. Source

Genet C.,CNRS Laboratory of Design and Application of Bioactive Molecules | Genet C.,Novalix Inc. | Strehle A.,University of Strasbourg | Schmidt C.,PhytoDia | And 7 more authors.
Journal of Medicinal Chemistry

We describe here the biological screening of a collection of natural occurring triterpenoids against the G protein-coupled receptor TGR5, known to be activated by bile acids and which mediates some important cell functions. This work revealed that betulinic (1), oleanolic (2), and ursolic acid (3) exhibited TGR5 agonist activity in a selective manner compared to bile acids, which also activated FXR, the nuclear bile acid receptor. The most potent natural triterpenoid betulinic acid was chosen as a reference compound for an SAR study. Hemisyntheses were performed on the betulinic acid scaffold, and we focused on structural modifications of the C-3 alcohol, the C-17 carboxylic acid, and the C-20 alkene. In particular, structural variations around the C-3 position gave rise to major improvements of potency exemplified with derivatives 18 dia 2 (RG-239) and 19 dia 2. The best derivative was tested in vitro and in vivo, and its biological profile is discussed. © 2009 American Chemical Society. Source

Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: HEALTH.2013.2.3.4-2 | Award Amount: 7.92M | Year: 2013

The trypanosomatid diseases, leishmaniasis, Human African trypanosomiasis (HAT) and Chagas disease (CD), continue to impart a heavy toll on human health. The treatments available are limited and threatened by drug resistance with few newdrugs in the pipeline. The KINDReD consortium integrates five leading academic laboratories in Europe (Portugal, United Kingdom, and Switzerland), the USA (California) and South America (Brazil) with high throughput screening (HTS) facilities equally distributed between all three major kinetoplastid parasites. Intracellular amastigote screening will be employed as the most relevant for Leishmania spp and T cruzi. Compound libraries (focused, diversity oriented or natural) will be screened in these systems, as well as compound series devised through target screening and in silico approaches. For carefully chosen protein targets, all three kinetoplastid parasite homologs will be screened against the closest human homolog to establish selectivity. Promising lead compounds will be optimised for efficacy and tolerability in cell-based and animal disease models. Toxicological markers will be evaluated in human cell lines prior to toxicity (acute,subacute,chronic) testing in lower then higher mammals. In parallel, and in line with the FDAs Critical Path Initiative, several check point controls will be built into the pipeline to flag, identify and allow early correction of potential toxicity/efficacy issues. These will include (i) a systems biology approach to identify drug target and off-target interactions via activity-based chemoproteomics (ii) uptake and metabolismas potential modulators of drug efficacy and/or resistance and (iii) the establishment of a firm set of rules for drug efficacy and safety in kinetoplastid chemotherapy. Our goal is to strengthen the drug development pipeline in order to achieve at least one new Phase I clinical candidate for each trypanosomatid disease at or shortly after the project completion date.

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