24 research outputs found

    “Don’t blame the shopkeeper!!” Food, drink and confectionery advertising and British Government market controls during the Second World War

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    A novel series of \u3b2-lactam derivatives that was designed and synthesized to target RGD-binding and leukocyte integrins is reported. The compound library was evaluated by investigating the effects on integrin-mediated cell adhesion and cell signaling in cell lines expressing \u3b1v\u3b23, \u3b1v\u3b25, \u3b1v\u3b26, \u3b15\u3b21, \u3b1IIb\u3b23, \u3b14\u3b21, and \u3b1L\u3b22 integrins. SAR analysis of the new series of azetidinones enabled the recognition of structural elements associated with integrin selectivity. We obtained selective and potent agonists that could induce cell adhesion and promote cell signaling mediated by \u3b1v\u3b23, \u3b1v\u3b25, \u3b15\u3b21, or \u3b14\u3b21 integrin, and antagonists for the integrins \u3b1v\u3b23 and \u3b15\u3b21, as well as \u3b14\u3b21 and \u3b1L\u3b22, preventing the effects elicited by the respective endogenous agonists

    A combined fragment-based virtual screening and STD-NMR approach for the identification of E-cadherin ligands

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    Cadherins promote cell-cell adhesion by forming homophilic interactions via their N-terminal extracellular domains. Hence, they have broad-ranging physiological effects on tissue organization and homeostasis. When dysregulated, cadherins contribute to different aspects of cancer progression and metastasis; therefore, targeting the cadherin adhesive interface with small-molecule antagonists is expected to have potential therapeutic and diagnostic value. Here, we used molecular docking simulations to evaluate the propensity of three different libraries of commercially available drug-like fragments (nearly 18,000 compounds) to accommodate into the Trp2 binding pocket of E-cadherin, a crucial site for the orchestration of the protein’s dimerization mechanism. Top-ranked fragments featuring five different aromatic chemotypes were expanded by means of a similarity search on the PubChem database (Tanimoto index >90%). Of this set, seven fragments containing an aromatic scaffold linked to an aliphatic chain bearing at least one amine group were finally selected for further analysis. Ligand-based NMR data (Saturation Transfer Difference, STD) and molecular dynamics simulations suggest that these fragments can bind E-cadherin mostly through their aromatic moiety, while their aliphatic portions may also diversely engage with the mobile regions of the binding site. A tetrahydro-β-carboline scaffold functionalized with an ethylamine emerged as the most promising fragment

    Molecular Dynamics Simulation of Aqueous Solutions of Trimethylamine-N-oxide and tert-Butyl Alcohol

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    In this work we have investigated hydration properties of aqueous solutions up to a solute molar fraction X2 = 0.125 of two isosteric molecules \u2013 the bioprotectant trimethylamine-N-oxide (TMAO) and the denaturant tert-butyl alcohol (TBA) \u2013 using molecular dynamics simulation at 298 K. Statistical analyses of the trajectories show in particular that as the solute concentration increases the number of the water molecules in the first hydration shell decreases uniformly for TMAO, while for TBA it decreases more rapidly in a concentration range where experiments indicate that TBA starts to self-aggregate. No appreciable solute segregation occurs for TMAO even in the most concentrated solution, where on the average each water molecule is shared by two solutes. This result parallels what has been recently found for glycine betaine, an organic osmolyte closely related to TMAO

    Extremely localized molecular orbitals: theory and applications

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    International audienc

    New Chemotypes for the Inhibition of (p)ppGpp Synthesis in the Quest for New Antimicrobial Compounds

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    Antimicrobial resistance (AMR) poses a serious threat to our society from both the medical and economic point of view, while the antibiotic discovery pipeline has been dwindling over the last decades. Targeting non-essential bacterial pathways, such as those leading to antibiotic persistence, a bacterial bet-hedging strategy, will lead to new molecular entities displaying low selective pressure, thereby reducing the insurgence of AMR. Here, we describe a way to target (p)ppGpp (guanosine tetra- or penta-phosphate) signaling, a non-essential pathway involved in the formation of persisters, with a structure-based approach. A superfamily of enzymes called RSH (RelA/SpoT Homolog) regulates the intracellular levels of this alarmone. We virtually screened several fragment libraries against the (p)ppGpp synthetase domain of our RSH chosen model RelSeq, selected three main chemotypes, and measured their interaction with RelSeq by thermal shift assay and STD-NMR. Most of the tested fragments are selective for the synthetase domain, allowing us to select the aminobenzoic acid scaffold as a hit for lead development

    High Affinity vs. Native Fibronectin in the Modulation of αvβ3 Integrin Conformational Dynamics: Insights from Computational Analyses and Implications for Molecular Design

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    <div><p>Understanding how binding events modulate functional motions of multidomain proteins is a major issue in chemical biology. We address several aspects of this problem by analyzing the differential dynamics of αvβ3 integrin bound to wild type (wtFN10, agonist) or high affinity (hFN10, antagonist) mutants of fibronectin. We compare the dynamics of complexes from large-scale domain motions to inter-residue coordinated fluctuations to characterize the distinctive traits of conformational evolution and shed light on the determinants of differential αvβ3 activation induced by different FN sequences. We propose an allosteric model for ligand-based integrin modulation: the conserved integrin binding pocket anchors the ligand, while different residues on the two FN10’s act as the drivers that reorganize relevant interaction networks, guiding the shift towards inactive (hFN10-bound) or active states (wtFN10-bound). We discuss the implications of results for the design of integrin inhibitors.</p></div
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