title: Integrated virtual screening for the identification of novel and selective peroxisome proliferator-activated receptor (PPAR) scaffolds.
abstract: We describe a fully customizable and integrated target-specific "tiered" virtual screening approach tailored to identifying and characterizing novel peroxisome proliferator activated receptor γ (PPARγ) scaffolds. Built on structure- and ligand-based computational techniques, a consensus protocol was developed for use in the virtual screening of chemical databases, focused toward retrieval of novel bioactive chemical scaffolds for PPARγ. Consequent from application, three novel PPAR scaffolds displaying distinct chemotypes have been identified, namely, 5-(4-(benzyloxy)-3-chlorobenzylidene)dihydro-2-thioxopyrimidine-4,6(1H,5H)-dione (MDG 548), 3-((4-bromophenoxy)methyl)-N-(4-nitro-1H-pyrazol-1-yl)benzamide (MDG 559), and ethyl 2-[3-hydroxy-5-(5-methyl-2-furyl)-2-oxo-4-(2-thienylcarbonyl)-2,5-dihydro-1H-pyrrol-1-yl]-4-methyl-1,3-thiazole-5-carboxylate (MDG 582). Fluorescence polarization(FP) and time resolved fluorescence resonance energy transfer (TR-FRET) show that these compounds display high affinity competitive binding to the PPARγ-LBD (EC(50) of 215 nM to 5.45 μM). Consequent characterization by a TR-FRET activation reporter assay demonstrated agonism of PPARγ by all three compounds (EC(50) of 467-594 nM). Additionally, differential PPAR isotype specificity was demonstrated through assay against PPARα and PPARδ subtypes. This work showcases the ability of target specific "tiered screen" protocols to successfully identify novel scaffolds of individual receptor subtypes with greater efficacy than isolated screening methods.
authors.affiliation: Molecular Design Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Nevin
authors.forename: Martin B
authors.initials: MB
authors.lastname: Peters
authors.forename: Giorgio
authors.initials: G
authors.lastname: Carta
authors.forename: Darren
authors.initials: D
authors.lastname: Fayne
authors.forename: David G
authors.initials: DG
authors.lastname: Lloyd
mesh_terms: D001549:Benzamides / Q000737:chemistry* / Q000494:pharmacology; D001667:Binding, Competitive; D016208:Databases, Factual; D005454:Fluorescence Polarization; D031541:Fluorescence Resonance Energy Transfer; D057809:HEK293 Cells; D006801:Humans; D008958:Models, Molecular; D047493:PPAR alpha / Q000819:agonists / Q000737:chemistry / Q000378:metabolism; D047494:PPAR delta / Q000819:agonists / Q000737:chemistry / Q000378:metabolism; D047495:PPAR gamma / Q000819:agonists / Q000737:chemistry / Q000378:metabolism; D047492:Peroxisome Proliferator-Activated Receptors / Q000819:agonists / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D011720:Pyrazoles / Q000737:chemistry* / Q000494:pharmacology; D011760:Pyrrolidinones / Q000737:chemistry* / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013844:Thiazoles / Q000737:chemistry* / Q000494:pharmacology; D013858:Thiobarbiturates / Q000737:chemistry* / Q000494:pharmacology
chemical_list: C575275:3-((4-bromophenoxy)methyl)-N-(4-nitro-1H-pyrazol-1-yl)benzamide; C575274:5-(4-(benzyloxy)-3-chlorobenzylidene)dihydro-2-thioxopyrimidine-4,6(1H,5H)-dione; D001549:Benzamides; D047493:PPAR alpha; D047494:PPAR delta; D047495:PPAR gamma; D047492:Peroxisome Proliferator-Activated Receptors; D011720:Pyrazoles; D011760:Pyrrolidinones; D013844:Thiazoles; D013858:Thiobarbiturates; C575276:ethyl 2-(3-hydroxy-5-(5-methyl-2-furyl)-2-oxo-4-(2-thienylcarbonyl)-2,5-dihydro-1H-pyrrol-1-yl)-4-methyl-1,3-thiazole-5-carboxylate