Guzman J.D.,University of London |
Guzman J.D.,University College London |
Evangelopoulos D.,University of London |
Evangelopoulos D.,University College London |
And 8 more authors.
BMJ Open | Year: 2013
Objectives: Lead antituberculosis (anti-TB) molecules with novel mechanisms of action are urgently required to fuel the anti-TB drug discovery pipeline. The aim of this study was to validate the use of the high-throughput spot culture growth inhibition (HT-SPOTi) assay for screening libraries of compounds against Mycobacterium tuberculosis and to study the inhibitory effect of ibuprofen (IBP) and the other 2-arylpropanoic acids on the growth inhibition of M tuberculosis and other mycobacterial species. Methods: The HT-SPOTi method was validated not only with known drugs but also with a library of 47 confirmed anti-TB active compounds published in the ChEMBL database. Three over-the-counter non-steroidal anti-inflammatory drugs were also included in the screening. The 2-arylpropanoic acids, including IBP, were comprehensively evaluated against phenotypically and physiologically different strains of mycobacteria, and their cytotoxicity was determined against murine RAW264.7 macrophages. Furthermore, a comparative bioinformatic analysis was employed to propose a potential mycobacterial target. Results: IBP showed antitubercular properties while carprofen was the most potent among the 2-arylpropanoic class. A 3,5-dinitro-IBP derivative was found to be more potent than IBP but equally selective. Other synthetic derivatives of IBP were less active, and the free carboxylic acid of IBP seems to be essential for its anti-TB activity. IBP, carprofen and the 3,5-dinitro-IBP derivative exhibited activity against multidrug-resistant isolates and stationary phase bacilli. On the basis of the human targets of the 2-arylpropanoic analgesics, the protein initiation factor infB (Rv2839c) of M tuberculosis was proposed as a potential molecular target. Conclusions: The HT-SPOTi method can be employed reliably and reproducibly to screen the antimicrobial potency of different compounds. IBP demonstrated specific antitubercular activity, while carprofen was the most selective agent among the 2-arylpropanoic class. Activity against stationary phase bacilli and multidrug-resistant isolates permits us to speculate a novel mechanism of antimycobacterial action. Further medicinal chemistry and target elucidation studies could potentially lead to new therapies against TB.
Wright P.D.,Center for Therapeutics Discovery |
Weir G.,University of Oxford |
Cartland J.,Center for Therapeutics Discovery |
Tickle D.,Center for Therapeutics Discovery |
And 3 more authors.
Biochemical and Biophysical Research Communications | Year: 2013
TRESK is a two-pore domain potassium channel. Loss of function mutations have been linked to typical migraine with aura and due to TRESK's expression pattern and role in neuronal excitability it represents a promising therapeutic target. We developed a cell based assay using baculovirus transduced U20S cells to screen for activators of TRESK. Using a thallium flux system to measure TRESK channel activity we identified Cloxyquin as a novel activator. Cloxyquin was shown to have an EC50 of 3.8 μM in the thallium assay and displayed good selectivity against other potassium channels tested. Activity was confirmed using whole cell patch electrophysiology, with Cloxyquin causing a near two fold increase in outward current. The strategy presented here will be used to screen larger compound libraries with the aim of identifying novel chemical series which may be developed into new migraine prophylactics. © 2013 Elsevier Inc. All rights reserved.
Goncalves V.,Imperial College London |
Brannigan J.A.,University of York |
Whalley D.,Center for Therapeutics Discovery |
Ansell K.H.,Center for Therapeutics Discovery |
And 5 more authors.
Journal of Medicinal Chemistry | Year: 2012
N-Myristoyltransferase (NMT) is a prospective drug target against parasitic protozoa. Herein we report the successful discovery of a series of Plasmodium vivax NMT inhibitors by high-throughput screening. A high-resolution crystal structure of the hit compound in complex with NMT was obtained, allowing understanding of its novel binding mode. A set of analogues was designed and tested to define the chemical groups relevant for activity and selectivity. © 2012 American Chemical Society.
Chapman T.M.,Center for Therapeutics Discovery |
Osborne S.A.,Center for Therapeutics Discovery |
Wallace C.,Center for Therapeutics Discovery |
Birchall K.,Center for Therapeutics Discovery |
And 7 more authors.
Journal of Medicinal Chemistry | Year: 2014
A structure-guided design approach using a homology model of Plasmodium falciparum calcium-dependent protein kinase 1 (PfCDPK1) was used to improve the potency of a series of imidazopyridazine inhibitors as potential antimalarial agents. This resulted in high affinity compounds with PfCDPK1 enzyme IC 50 values less than 10 nM and in vitro P. falciparum antiparasite EC50 values down to 12 nM, although these compounds did not have suitable ADME properties to show in vivo efficacy in a mouse model. Structural modifications designed to address the ADME issues, in particular permeability, were initially accompanied by losses in antiparasite potency, but further optimization allowed a good balance in the compound profile to be achieved. Upon testing in vivo in a murine model of efficacy against malaria, high levels of compound exposure relative to their in vitro activities were achieved, and the modest efficacy that resulted raises questions about the level of effect that is achievable through the targeting of PfCDPK1. © 2014 American Chemical Society.
Rocheville M.,Glaxosmithkline |
Martin J.,Glaxosmithkline |
Jerman J.,Center for Therapeutics Discovery |
Kostenis E.,University of Bonn
Progress in Molecular Biology and Translational Science | Year: 2013
Label-free is a broad term used to describe a number of cutting-edge biosensor technologies that have attracted considerable attention in the area of drug discovery for seven-transmembrane G protein-coupled receptors (GPCRs). Label-free biosensors resolve receptor-mediated responses noninvasively in real time and living cells and do so with high textural information and broad signaling-pathway coverage. They should facilitate studies of the receptor's integrated signal transduction biology intractable to classical assays with single pathway focus. Label-free occupies a privilege niche with respect to mechanistic studies in human native cells - healthy or disease-relevant - and the probing of context-dependent pharmacology in relation to whole biological system efficacy. It is expected that implementation of label-free approaches into the drug discovery process will improve clinical predictability of drug candidates at early stages of discovery research by their exquisite capability to sense whole cellular responses akin to tissue bioassays. Here, we present an overview of promises and challenges this rapidly evolving technology offers to drug screening and we also discuss the prospect of advancing drug discovery. © 2013 Elsevier Inc.
Andrews D.M.,Astrazeneca |
Swarbrick M.E.,Cancer Research Technology |
Merritt A.T.,Center for Therapeutics Discovery
Drug Discovery Today | Year: 2014
In response to the dual challenges of increasingly risky target portfolios and realignment of traditional pharmaceutical company resources away from early-phase research and development (R&D), research groups have sought to engage across the industrial and not-for-profit divide, resulting in the emergence of many different collaborative models. Here, we describe two successful collaborations based upon shared commitment and risk. The risks and complexities of external collaboration can be mitigated by appropriate agreements and tools, but we found that it remains essential that the collaborating scientists adopt a collaborative mindset and embrace the diverse ways of working of partner organizations. © 2014 Elsevier Ltd.
MacKenzie A.E.,University of Glasgow |
Lappin J.E.,University of Glasgow |
Taylor D.L.,Center for Therapeutics Discovery |
Nicklin S.A.,University of Glasgow |
Milligan G.,University of Glasgow
Frontiers in Endocrinology | Year: 2011
G protein-coupled receptors (GPCRs) remain the best studied class of cell surface recep-tors and the most tractable family of proteins for novel small molecule drug discovery. Despite this, a considerable number of GPCRs remain poorly characterized and in a signif-icant number of cases, endogenous ligand(s) that activate them remain undefined or are of questionable physiological relevance. GPR35 was initially discovered over a decade ago but has remained an "orphan" receptor. Recent publications have highlighted novel ligands, both endogenously produced and synthetic, which demonstrate significant potency at this receptor. Furthermore, evidence is accumulating which highlights potential roles for GPR35 in disease and therefore, efforts to characterize GPR35 more fully and develop it as a novel therapeutic target in conditions that range from diabetes and hypertension to asthma are increasing. Recently identified ligands have shown marked species selective properties, indicating major challenges for future drug development. As we begin to understand these issues, the continuing efforts to identify novel agonist and antagonist ligands for GPR35 will help to decipher its true physiological relevance; translating multiple assay systems in vitro, to animal disease systems in vivo and finally to man. © 2011 MacKenzie, Lappin, Taylor, Nicklin and Milligan.
Pierrat O.A.,University of Cambridge |
Strisovsky K.,University of Cambridge |
Christova Y.,University of Cambridge |
Large J.,Center for Therapeutics Discovery |
And 4 more authors.
ACS Chemical Biology | Year: 2011
Rhomboids are relatively recently discovered intramembrane serine proteases that are conserved throughout evolution. They have a wide range of biological functions, and there is also much speculation about their potential medical relevance. Although rhomboids are weakly inhibited by some broad-spectrum serine protease inhibitors, no potent and specific inhibitors have been identified for these enzymes, which are mechanistically distinct from and evolutionarily unrelated to the classical soluble serine proteases. Here we report a new biochemical assay for rhomboid function based on the use of quenched fluorescent substrate peptides. We have developed this assay into a high-throughput format and have undertaken an inhibitor and activator screen of approximately 58,000 small molecules. This has led to the identification of a new class of rhomboid inhibitors, a series of monocyclic β-lactams, which are more potent than any previous inhibitor. They show selectivity, both for rhomboids over the soluble serine protease chymotrypsin and also, importantly, between different rhomboids; they can inhibit mammalian as well as bacterial rhomboids; and they are effective both in vitro and in vivo. These compounds represent important templates for further inhibitor development, which could have an impact both on biological understanding of rhomboid function and potential future drug development. © 2010 American Chemical Society.
Newman A.C.,University of Edinburgh |
Scholefield C.L.,University of Edinburgh |
Kemp A.J.,University of Edinburgh |
Newman M.,Center for Therapeutics Discovery |
And 3 more authors.
PLoS ONE | Year: 2012
K-Ras dependent non-small cell lung cancer (NSCLC) cells are 'addicted' to basal autophagy that reprograms cellular metabolism in a lysosomal-sensitive manner. Here we demonstrate that the xenophagy-associated kinase TBK1 drives basal autophagy, consistent with its known requirement in K-Ras-dependent NSCLC proliferation. Furthermore, basal autophagy in this context is characterised by sequestration of the xenophagy cargo receptor Ndp52 and its paralogue Tax1bp1, which we demonstrate here to be a bona fide cargo receptor. Autophagy of these cargo receptors promotes non-canonical NF-κB signalling. We propose that this TBK1-dependent mechanism for NF-κB signalling contributes to autophagy addiction in K-Ras driven NSCLC. © 2012 Newman et al.
Vinothkumar K.R.,University of Cambridge |
Pierrat O.A.,University of Cambridge |
Pierrat O.A.,University of Reading |
Large J.M.,Center for Therapeutics Discovery |
And 2 more authors.
Structure | Year: 2013
Rhomboids are evolutionarily conserved serine proteases that cleave transmembrane proteins within the membrane. The increasing number of known rhomboid functions in prokaryotes and eukaryotes makes them attractive drug targets. Here, we describe structures of the Escherichia coli rhomboid GlpG in complex with β-lactam inhibitors. The inhibitors form a single bond to the catalytic serine and the carbonyl oxygen of the inhibitor faces away from the oxyanion hole. The hydrophobic N-substituent of β-lactam inhibitors points into a cavity within the enzyme, providing a structural explanation for the specificity of β-lactams on rhomboid proteases. This same cavity probably represents the S2′ substrate binding site of GlpG. We suggest that the structural changes in β-lactam inhibitor binding reflect the state of the enzyme at an initial stage of substrate binding to the active site. The structural insights from these enzyme-inhibitor complexes provide a starting point for structure-based design for rhomboid inhibitors. © 2013 Elsevier Ltd. All rights reserved.