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Ferrari F, Rizzo S, Ruzza C, Calo G. Detailed In Vitro Pharmacological Characterization of the Clinically Viable Nociceptin/Orphanin FQ Peptide Receptor Antagonist BTRX-246040. J Pharmacol Exp Ther 2020; 373:34-43. [PMID: 31937563 DOI: 10.1124/jpet.119.262865] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 01/07/2020] [Indexed: 12/20/2022] Open
Abstract
The peptide nociceptin/orphanin FQ (N/OFQ) is the natural ligand of the N/OFQ receptor (NOP), which is widely expressed in the central and peripheral nervous system. Selective NOP antagonists are worthy of testing as innovative drugs to treat depression, Parkinson disease, and drug abuse. The aim of this study was to perform a detailed in vitro characterization of BTRX-246040 (also known as LY2940094, [2-[4-[(2-chloro-4,4-difluoro-spiro[5H-thieno[2,3-c]pyran-7,4'-piperidine]-1'-yl)methyl]-3-methyl-pyrazol-1-yl]-3-pyridyl]methanol), a novel NOP antagonist that has been already studied in humans. BTRX-246040 has been tested in vitro in the following assays: calcium mobilization in cells expressing NOP and classic opioid receptors and chimeric G proteins, bioluminescence resonance energy transfer assay measuring NOP interaction with G proteins and β-arrestins, the label-free dynamic mass redistribution assay, and the electrically stimulated mouse vas deferens. BTRX-246040 was systematically compared with the standard NOP antagonist SB-612111. In all assays, BTRX-246040 behaves as a pure and selective antagonist at human recombinant and murine native NOP receptors displaying 3-10-fold higher potency than the standard antagonist SB-612111. BTRX-246040 is an essential pharmacological tool to further investigate the therapeutic potential of NOP antagonists in preclinical and clinical studies. SIGNIFICANCE STATEMENT: NOP antagonists may be innovative antidepressant drugs. In this research, the novel clinically viable NOP antagonist BTRX-246040 has been deeply characterized in vitro in a panel of assays. BTRX-246040 resulted a pure, potent, and selective NOP antagonist.
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Affiliation(s)
- Federica Ferrari
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, Ferrara, Italy (F.F., S.R., C.R., G.C.) and Technopole of Ferrara, LTTA Laboratory for Advanced Therapies, Ferrara, Italy (C.R.)
| | - Sabrina Rizzo
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, Ferrara, Italy (F.F., S.R., C.R., G.C.) and Technopole of Ferrara, LTTA Laboratory for Advanced Therapies, Ferrara, Italy (C.R.)
| | - Chiara Ruzza
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, Ferrara, Italy (F.F., S.R., C.R., G.C.) and Technopole of Ferrara, LTTA Laboratory for Advanced Therapies, Ferrara, Italy (C.R.)
| | - Girolamo Calo
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, Ferrara, Italy (F.F., S.R., C.R., G.C.) and Technopole of Ferrara, LTTA Laboratory for Advanced Therapies, Ferrara, Italy (C.R.)
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Della Longa S, Arcovito A. Microswitches for the Activation of the Nociceptin Receptor Induced by Cebranopadol: Hints from Microsecond Molecular Dynamics. J Chem Inf Model 2019; 59:818-831. [PMID: 30640458 DOI: 10.1021/acs.jcim.8b00759] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cebranopadol (CBP) is a novel analgesic acting as agonist at the nociceptin (NOP) and μ-opioid (MOP) receptors, exhibiting high potency and efficacy as an antinociceptive and antihypersensitive drug. The binding conformation and the dynamical interactions of CBP with the NOP receptor have been investigated by molecular docking, molecular dynamics (MD) in the microsecond time scale, and hybrid quantum mechanics/molecular mechanics (QM/MM). CBP binds to the NOP receptor as a bidentate ligand of the aspartate D1303,32 by means of both its fluoroindole and dimethyl nitrogens. Starting from the known crystal structure of the inactive state of the receptor, in complex with the antagonist compound-24 (NOP-C24) the comparative analysis of 1 μs MD trajectories of the NOP-C24 complex itself and the NOP_free and NOP-CBP complexes provides new insights on the already known microswitches related to receptor activation, in the frame of the extended ternary complex model. The agonist acts by destabilizing the inactive conformation of the NOP receptor, by inducing a conformational change of M1343,36, which allows W2766,48 to flip around its χ2 dihedral, going in close proximity to the receptor hydrophobic core (T1383,40, P2275,50, F2726,44), which is known to be fundamental for the activation of the opioid receptors. A complete rational picture is also provided for the role of N1333,35 and W2766,48 undergoing critical conformational changes related to an anticooperativity effect, i.e. the well-known role of sodium as negative modulator of agonist binding. Finally, the movement of residue Y3197,53 belonging to the NPxxY motif is also induced by the binding of the agonist in the inactive state, opening a gate for a water channel just as upon receptor activation.
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Affiliation(s)
- Stefano Della Longa
- Department of Life, Health and Environmental Sciences , University of L'Aquila , L'Aquila , 67100 Italy
| | - Alessandro Arcovito
- Istituto di Biochimica e Biochimica Clinica , Università Cattolica del Sacro Cuore , Rome , 00168 Italy.,Fondazione Policlinico Universitario A. Gemelli - IRCCS, Rome , 00168 Italy
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Abstract
The nociceptin/orphanin FQ (N/OFQ) peptide receptor (NOP) is a G protein-coupled receptor involved in the regulation of several physiological functions and pathological conditions. Thus, researchers from academia and industry are pursuing NOP to discover and study novel pharmacological entities. In a multidisciplinary effort of pharmacologists, medicinal chemists, and molecular and structural biologists the mechanisms of NOP activation and inhibition have been, at least partially, disentangled. Here, we review the in vitro methodologies employed, which have contributed to our understanding of this target. We hope this chapter guides the reader through the mostly established assay platforms to investigate NOP pharmacology, and gives some hints taking advantage from what has already illuminated the function of other GPCRs. We analyzed the pharmacological results obtained with a large panel of NOP ligands investigated in several assays including receptor binding, stimulation of GTPγS binding, decrease of cAMP levels, calcium flux stimulation via chimeric G proteins, NOP/G protein and NOP/β-arrestin interaction, label-free assays such as dynamic mass redistribution, and bioassays such as the electrically stimulated mouse vas deferens.
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Affiliation(s)
- Davide Malfacini
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Girolamo Caló
- Section of Pharmacology, Department of Medical Sciences, National Institute of Neurosciences, University of Ferrara, Ferrara, Italy.
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Cong X, Golebiowski J. Allosteric Na +-binding site modulates CXCR4 activation. Phys Chem Chem Phys 2018; 20:24915-24920. [PMID: 30238101 DOI: 10.1039/c8cp04134b] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
G protein-coupled receptors (GPCRs) control most cellular communications with the environment and are the largest protein family of drug targets. As strictly regulated molecular machines, profound comprehension of their activation mechanism is expected to significantly facilitate structure-based drug design. This study provides atomistic-level description of the activation dynamics of the C-X-C chemokine receptor type 4 (CXCR4), a class A GPCR and important drug target. Using molecular dynamics and enhanced sampling, we demonstrate how mutations and protonation of conserved residues trigger activation through microswitches at the receptor core, while sodium ion - a known allosteric modulator - inhibits it. The findings point to a conserved mechanism of activation and the allosteric modulation by sodium in the chemokine receptor family. From the technical aspect, the enhanced sampling protocol effectively samples receptor conformational changes toward activation, and differentiates three variants of the receptor by their basal activity. This work provides structural basis and a powerful in silico tool for CXCR4 agonist design.
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Affiliation(s)
- Xiaojing Cong
- Université Côte d'Azur, CNRS, Institut de Chimie de Nice UMR7272, 06108 Nice, France.
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Alkozi HA, Sánchez Montero JM, Doadrio AL, Pintor J. Docking studies for melatonin receptors. Expert Opin Drug Discov 2017; 13:241-248. [PMID: 29271261 DOI: 10.1080/17460441.2018.1419184] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Melatonin is a neurohormone that controls many relevant physiological processes beyond the control of circadian rhythms. Melatonin's actions are carried out by two main types of melatonin receptors; MT1 and MT2. These receptors are important, and not just because of the biological actions of its natural agonist; but also, because melatonin analogues can improve or antagonize their biological effect. Area covered: The following article describes the importance of melatonin as a biologically relevant molecule. It also defines the receptors for this substance, as well as the second messengers coupled to these receptors. Lastly, the article describes the amino acid residues involved in the docking process in both MT1 and MT2 melatonin receptors. Expert opinion: The biological actions of melatonin and their interpretations are becoming more relevant and therefore require the development of new pharmacological tools. Understanding the second messenger mechanisms involved in melatonin actions, as well as the characteristics of the docking of this molecule to MT1 and MT2 melatonin receptors, will permit the development of more selective agonists and antagonists which will help us to better understand this molecule as well to develop new therapeutic compounds.
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Affiliation(s)
- Hanan Awad Alkozi
- a Department of Biochemistry and Molecular Biology IV, Faculty of Optometry , Universidad Complutense de Madrid , Madrid , Spain
| | - José Maria Sánchez Montero
- b Department of Organic Chemistry and Pharmaceutical, Faculty of Pharmacy , Ciudad Universitaria , Madrid , Spain
| | - Antonio Luis Doadrio
- c Department of Inorganic Chemistry and Bioorganic, Faculty of Pharmacy , University Complutense of Madrid , Ciudad Universitaria, Madrid , Spain
| | - Jesus Pintor
- a Department of Biochemistry and Molecular Biology IV, Faculty of Optometry , Universidad Complutense de Madrid , Madrid , Spain
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Hayashi S, Ohashi K, Mihara S, Nakata E, Emoto C, Ohta A. Discovery of small-molecule nonpeptide antagonists of nociceptin/orphanin FQ receptor: The studies of design, synthesis, and structure–activity relationships for (4-arylpiperidine substituted-methyl)-[bicyclic (hetero)cycloalkanobenzene] derivatives. Eur J Med Chem 2016; 114:345-64. [DOI: 10.1016/j.ejmech.2016.02.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 01/06/2016] [Accepted: 02/04/2016] [Indexed: 11/16/2022]
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Toll L, Bruchas MR, Calo' G, Cox BM, Zaveri NT. Nociceptin/Orphanin FQ Receptor Structure, Signaling, Ligands, Functions, and Interactions with Opioid Systems. Pharmacol Rev 2016; 68:419-57. [PMID: 26956246 PMCID: PMC4813427 DOI: 10.1124/pr.114.009209] [Citation(s) in RCA: 213] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The NOP receptor (nociceptin/orphanin FQ opioid peptide receptor) is the most recently discovered member of the opioid receptor family and, together with its endogenous ligand, N/OFQ, make up the fourth members of the opioid receptor and opioid peptide family. Because of its more recent discovery, an understanding of the cellular and behavioral actions induced by NOP receptor activation are less well developed than for the other members of the opioid receptor family. All of these factors are important because NOP receptor activation has a clear modulatory role on mu opioid receptor-mediated actions and thereby affects opioid analgesia, tolerance development, and reward. In addition to opioid modulatory actions, NOP receptor activation has important effects on motor function and other physiologic processes. This review discusses how NOP pharmacology intersects, contrasts, and interacts with the mu opioid receptor in terms of tertiary structure and mechanism of receptor activation; location of receptors in the central nervous system; mechanisms of desensitization and downregulation; cellular actions; intracellular signal transduction pathways; and behavioral actions with respect to analgesia, tolerance, dependence, and reward. This is followed by a discussion of the agonists and antagonists that have most contributed to our current knowledge. Because NOP receptors are highly expressed in brain and spinal cord and NOP receptor activation sometimes synergizes with mu receptor-mediated actions and sometimes opposes them, an understanding of NOP receptor pharmacology in the context of these interactions with the opioid receptors will be crucial to the development of novel therapeutics that engage the NOP receptor.
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Affiliation(s)
- Lawrence Toll
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida (L.T.); Departments of Anesthesiology, and Neuroscience, Washington University School of Medicine, St. Louis, Missouri (M.R.B.); Section of Pharmacology, Department of Medical Science, and National Institute of Neurosciences, University of Ferrara, Ferrara, Italy (G.C.); Professor of Pharmacology & Neuroscience, Uniformed Services University, Bethesda, Maryland (B.M.C.); and Astraea Therapeutics, LLC, Mountain View, California (N.T.Z.)
| | - Michael R Bruchas
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida (L.T.); Departments of Anesthesiology, and Neuroscience, Washington University School of Medicine, St. Louis, Missouri (M.R.B.); Section of Pharmacology, Department of Medical Science, and National Institute of Neurosciences, University of Ferrara, Ferrara, Italy (G.C.); Professor of Pharmacology & Neuroscience, Uniformed Services University, Bethesda, Maryland (B.M.C.); and Astraea Therapeutics, LLC, Mountain View, California (N.T.Z.)
| | - Girolamo Calo'
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida (L.T.); Departments of Anesthesiology, and Neuroscience, Washington University School of Medicine, St. Louis, Missouri (M.R.B.); Section of Pharmacology, Department of Medical Science, and National Institute of Neurosciences, University of Ferrara, Ferrara, Italy (G.C.); Professor of Pharmacology & Neuroscience, Uniformed Services University, Bethesda, Maryland (B.M.C.); and Astraea Therapeutics, LLC, Mountain View, California (N.T.Z.)
| | - Brian M Cox
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida (L.T.); Departments of Anesthesiology, and Neuroscience, Washington University School of Medicine, St. Louis, Missouri (M.R.B.); Section of Pharmacology, Department of Medical Science, and National Institute of Neurosciences, University of Ferrara, Ferrara, Italy (G.C.); Professor of Pharmacology & Neuroscience, Uniformed Services University, Bethesda, Maryland (B.M.C.); and Astraea Therapeutics, LLC, Mountain View, California (N.T.Z.)
| | - Nurulain T Zaveri
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida (L.T.); Departments of Anesthesiology, and Neuroscience, Washington University School of Medicine, St. Louis, Missouri (M.R.B.); Section of Pharmacology, Department of Medical Science, and National Institute of Neurosciences, University of Ferrara, Ferrara, Italy (G.C.); Professor of Pharmacology & Neuroscience, Uniformed Services University, Bethesda, Maryland (B.M.C.); and Astraea Therapeutics, LLC, Mountain View, California (N.T.Z.)
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Malfacini D, Ambrosio C, Gro’ MC, Sbraccia M, Trapella C, Guerrini R, Bonora M, Pinton P, Costa T, Calo’ G. Pharmacological Profile of Nociceptin/Orphanin FQ Receptors Interacting with G-Proteins and β-Arrestins 2. PLoS One 2015; 10:e0132865. [PMID: 26248189 PMCID: PMC4527783 DOI: 10.1371/journal.pone.0132865] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 06/18/2015] [Indexed: 01/11/2023] Open
Abstract
Nociceptin/orphanin FQ (N/OFQ) controls several biological functions by selectively activating an opioid like receptor named N/OFQ peptide receptor (NOP). Biased agonism is emerging as an important and therapeutically relevant pharmacological concept in the field of G protein coupled receptors including opioids. To evaluate the relevance of this phenomenon in the NOP receptor, we used a bioluminescence resonance energy transfer technology to measure the interactions of the NOP receptor with either G proteins or β-arrestin 2 in the absence and in presence of increasing concentration of ligands. A large panel of receptor ligands was investigated by comparing their ability to promote or block NOP/G protein and NOP/arrestin interactions. In this study we report a systematic analysis of the functional selectivity of NOP receptor ligands. NOP/G protein interactions (investigated in cell membranes) allowed a precise estimation of both ligand potency and efficacy yielding data highly consistent with the known pharmacological profile of this receptor. The same panel of ligands displayed marked differences in the ability to promote NOP/β-arrestin 2 interactions (evaluated in whole cells). In particular, full agonists displayed a general lower potency and for some ligands an inverted rank order of potency was noted. Most partial agonists behaved as pure competitive antagonists of receptor/arrestin interaction. Antagonists displayed similar values of potency for NOP/Gβ1 or NOP/β-arrestin 2 interaction. Using N/OFQ as reference ligand we computed the bias factors of NOP ligands and a number of agonists with greater efficacy at G protein coupling were identified.
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Affiliation(s)
- D. Malfacini
- Department of Medical Sciences, Section of Pharmacology and National Institute of Neuroscience, University of Ferrara, Ferrara, Italy
| | - C. Ambrosio
- Department of Pharmacology, Istituto Superiore di Sanità, Rome, Italy
| | - M. C. Gro’
- Department of Pharmacology, Istituto Superiore di Sanità, Rome, Italy
| | - M. Sbraccia
- Department of Pharmacology, Istituto Superiore di Sanità, Rome, Italy
| | - C. Trapella
- Department of Chemical and Pharmaceutical Sciences and LTTA, University of Ferrara, Ferrara, Italy
| | - R. Guerrini
- Department of Chemical and Pharmaceutical Sciences and LTTA, University of Ferrara, Ferrara, Italy
| | - M. Bonora
- Department of Morphology, Surgery, and Experimental Medicine, Section of Pathology, Oncology, and Experimental Biology and LTTA, University of Ferrara, Ferrara, Italy
| | - P. Pinton
- Department of Morphology, Surgery, and Experimental Medicine, Section of Pathology, Oncology, and Experimental Biology and LTTA, University of Ferrara, Ferrara, Italy
| | - T. Costa
- Department of Pharmacology, Istituto Superiore di Sanità, Rome, Italy
| | - G. Calo’
- Department of Medical Sciences, Section of Pharmacology and National Institute of Neuroscience, University of Ferrara, Ferrara, Italy
- * E-mail:
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Senćanski M, Došen-Mićović L. In Silico Study of the Structurally Similar ORL1 Receptor Agonist and Antagonist Pairs Reveal Possible Mechanism of Receptor Activation. Protein J 2014; 33:231-42. [DOI: 10.1007/s10930-014-9555-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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10
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Homology models of melatonin receptors: challenges and recent advances. Int J Mol Sci 2013; 14:8093-121. [PMID: 23584026 PMCID: PMC3645733 DOI: 10.3390/ijms14048093] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 03/28/2013] [Accepted: 03/28/2013] [Indexed: 12/15/2022] Open
Abstract
Melatonin exerts many of its actions through the activation of two G protein-coupled receptors (GPCRs), named MT1 and MT2. So far, a number of different MT1 and MT2 receptor homology models, built either from the prototypic structure of rhodopsin or from recently solved X-ray structures of druggable GPCRs, have been proposed. These receptor models differ in the binding modes hypothesized for melatonin and melatonergic ligands, with distinct patterns of ligand-receptor interactions and putative bioactive conformations of ligands. The receptor models will be described, and they will be discussed in light of the available information from mutagenesis experiments and ligand-based pharmacophore models. The ability of these ligand-receptor complexes to rationalize structure-activity relationships of known series of melatonergic compounds will be commented upon.
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11
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Hayashi S, Ohashi K, Nakata E, Emoto C. Discovery of 1-(β-amino substituted-β-alanyl)-N,N-dimethylindoline-2-carboxamides as novel nonpeptide antagonists of nociceptin/orphanin FQ receptor: Efficient design, synthesis, and structure–activity relationship studies. Eur J Med Chem 2012; 55:228-42. [DOI: 10.1016/j.ejmech.2012.07.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 07/11/2012] [Accepted: 07/15/2012] [Indexed: 12/01/2022]
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Daga PR, Zaveri NT. Homology modeling and molecular dynamics simulations of the active state of the nociceptin receptor reveal new insights into agonist binding and activation. Proteins 2012; 80:1948-61. [PMID: 22489047 DOI: 10.1002/prot.24077] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 03/01/2012] [Accepted: 03/12/2012] [Indexed: 11/11/2022]
Abstract
The opioid receptor-like receptor, also known as the nociceptin receptor (NOP), is a class A G protein-coupled receptor (GPCR) in the opioid receptor family. Although NOP shares a significant homology with the other opioid receptors, it does not bind known opioid ligands and has been shown to have a distinct mechanism of activation compared to the closely related opioid receptors mu, delta, and kappa. Previously reported homology models of the NOP receptor, based on the inactive-state GPCR crystal structures, give limited information on the activation and selectivity features of this fourth member of the opioid receptor family. We report here the first active-state homology model of the NOP receptor based on the opsin GPCR crystal structure. An inactive-state homology model of NOP was also built using a multiple template approach. Molecular dynamics simulation of the active-state NOP model and comparison to the inactive-state model suggest that NOP activation involves movements of transmembrane (TM)3 and TM6 and several activation microswitches, consistent with GPCR activation. Docking of the selective nonpeptidic NOP agonist ligand Ro 64-6198 into the active-state model reveals active-site residues in NOP that play a role in the high selectivity of this ligand for NOP over the other opioid receptors. Docking the shortest active fragment of endogenous agonist nociceptin/orphaninFQ (residues 1-13) shows that the NOP extracellular loop 2 (EL2) loop interacts with the positively charged residues (8-13) of N/OFQ. Both agonists show extensive polar interactions with residues at the extracellular end of the TM domain and EL2 loop, suggesting agonist-induced reorganization of polar networks, during receptor activation.
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Affiliation(s)
- Pankaj R Daga
- Astraea Therapeutics, LLC, 320 Logue Avenue, Mountain View, California 94043, USA
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13
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Liu M, He L, Hu X, Liu P, Luo HB. 3D-QSAR, homology modeling, and molecular docking studies on spiropiperidines analogues as agonists of nociceptin/orphanin FQ receptor. Bioorg Med Chem Lett 2010; 20:7004-10. [DOI: 10.1016/j.bmcl.2010.09.116] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 09/22/2010] [Accepted: 09/24/2010] [Indexed: 11/30/2022]
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14
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Ahmed M, Muntasir HA, Hossain M, Ishiguro M, Komiyama T, Muramatsu I, Kurose H, Nagatomo T. Beta-blockers show inverse agonism to a novel constitutively active mutant of beta1-adrenoceptor. J Pharmacol Sci 2006; 102:167-72. [PMID: 17031074 DOI: 10.1254/jphs.fp0060640] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
We obtained a new mutant of the beta(1)-adrenergic receptor (beta(1)-AR) by point mutations that can constitutively activate beta(1)-AR. Aspartate104 of the beta(1)-AR in the 2nd transmembrane was replaced with alanine. The beta(1)-AR mutant expressed in human embryonic kidney (HEK)-293 cells displayed high level of constitutive activity with respect to wild-type (P<0.05), which could be partially inhibited by some beta-blockers. The constitutive activity of the mutant was confirmed by the finding that the enhanced activity is dependent on the level of receptor expression. The results of this study might have interesting implications for future studies aiming at elucidating the activation process of the beta(1)-AR as well as the mechanism of action of beta-blockers.
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Affiliation(s)
- Maruf Ahmed
- Pharmacy Department, University of Rajshahi, Bangladesh
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Abstract
Opioid receptors belong to the large superfamily of seven transmembrane-spanning (7TM) G protein-coupled receptors (GPCRs). As a class, GPCRs are of fundamental physiological importance mediating the actions of the majority of known neurotransmitters and hormones. Opioid receptors are particularly intriguing members of this receptor family. They are activated both by endogenously produced opioid peptides and by exogenously administered opiate compounds, some of which are not only among the most effective analgesics known but also highly addictive drugs of abuse. A fundamental question in addiction biology is why exogenous opioid drugs, such as morphine and heroin, have a high liability for inducing tolerance, dependence, and addiction. This review focuses on many aspects of opioid receptors with the aim of gaining a greater insight into mechanisms of opioid tolerance and dependence.
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Affiliation(s)
- Maria Waldhoer
- Ernest Gallo Clinic and Research Center, University of California, San Francisco, Emeryville, California 94608, USA.
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New DC, Wong YH. Characterization of CHO Cells Stably Expressing a Gα16/zChimera for High Throughput Screening of GPCRs. Assay Drug Dev Technol 2004; 2:269-80. [PMID: 15285908 DOI: 10.1089/1540658041410641] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are important therapeutic targets for drug discovery. The identification and characterization of new ligands ideally requires the use of high throughput assays that are applicable to all GPCR subtypes. To circumvent the problem of different GPCRs coupling to distinct intracellular second messenger pathways, we describe a new method that uses the chimeric Galpha protein 16z25 to facilitate this process. Stably expressed in Chinese hamster ovary cells, 16z25 allows G(i/o)- and G(s)-coupled receptors to mobilize intracellular Ca(2+) upon agonist stimulation. We have generated nine cell lines each stably expressing 16z25 and a GPCR. All cell lines respond to appropriate agonist stimulation in fluorometric imaging plate reader (FLIPR) assays with robust and potent Ca(2+) mobilization. Several of these lines have been pharmacologically characterized using agonists and antagonists. We also demonstrate that the coexpression of GPCR and 16z25 does not interfere with the receptors' ability to activate endogenous signaling pathways. The ability of 16z25 to functionally mediate the agonist stimulation of a broad spectrum of GPCRs indicates that the use of cell lines stably coexpressing this chimera and GPCRs will simplify the drug screening process and aid in the deorphanization of new receptors.
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Affiliation(s)
- David C New
- Department of Biochemistry, Hong Kong University of Science and Technology, Clearwater Bay, Hong Kong, China
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Abstract
This paper is the twenty-fifth consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over a quarter-century of research. It summarizes papers published during 2002 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, CUNY, 65-30 Kissena Blvd., Flushing, NY 11367, USA.
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