1
|
Saleh AH, Abdelwaly A, Darwish KM, Eissa AAHM, Chittiboyina A, Helal MA. Deciphering the molecular basis of the kappa opioid receptor selectivity: A Molecular Dynamics study. J Mol Graph Model 2021; 106:107940. [PMID: 34015577 DOI: 10.1016/j.jmgm.2021.107940] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 12/30/2022]
Abstract
Selective antagonists for the kappa opioid receptor (KOP) have the potential to treat opiate and alcohol addiction, as well as depression and other CNS disorders. Over the years, the development of KOP-selective antagonists yielded very few successful compounds. Recently, N-substituted trans-3,4-dimethyl-4-(3-hydroxyphenyl)piperidines have emerged as a novel class of pure opioid receptor antagonists, including the marketed Mu opioid receptor (MOP) peripheral antagonist Alvimopan and the potent KOP antagonist JDTic. However, the selectivity determinants of this class of compounds towards the opioid receptor subtypes are still vague and understudied. In this work, we have performed Molecular Dynamics (MD) simulation to gain insights into the differential binding of this class of compounds into KOP, as exemplified by Alvimopan and JDTic. Our study indicated that the selectivity largely depends on ligands interaction with the selectivity pocket formed by Val108, Thr111, and Val118, supported by two additional polar and hydrophobic contacts with Asp138 and Trp287, respectively. Our results also demonstrate, for the first time, that non-morphinan ligands can still adopt the "message-address model" for KOP efficacy and selectivity by binding to Glu297.
Collapse
Affiliation(s)
- Amr H Saleh
- University of Science and Technology, Biomedical Sciences Program, Zewail City of Science and Technology, October Gardens, 6th of October, Giza, 12578, Egypt
| | - Ahmad Abdelwaly
- University of Science and Technology, Biomedical Sciences Program, Zewail City of Science and Technology, October Gardens, 6th of October, Giza, 12578, Egypt
| | - Khaled M Darwish
- Medicinal Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia, 41522, Egypt
| | - Amal A H M Eissa
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Amar Chittiboyina
- National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, MS, 38677, United States
| | - Mohamed A Helal
- University of Science and Technology, Biomedical Sciences Program, Zewail City of Science and Technology, October Gardens, 6th of October, Giza, 12578, Egypt; Medicinal Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia, 41522, Egypt.
| |
Collapse
|
2
|
Zaidi SA, Katritch V. Structural Characterization of KOR Inactive and Active States for 3D Pharmacology and Drug Discovery. Handb Exp Pharmacol 2021; 271:41-64. [PMID: 33945028 DOI: 10.1007/164_2021_461] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The structure of the human kappa opioid receptor (KOR) in complex with the long-acting antagonist JDTic was solved crystallographically in 2012 and, along with structures of other opioid receptors, revolutionized our understanding of opioid system function and pharmacology. More recently, active state KOR structure was also determined, giving important insights into activation mechanisms of the receptor. In this review, we will discuss how the understanding of atomistic structures of KOR established a key platform for deciphering details of subtype and functional selectivity of KOR-targeting ligands and for discovery of new chemical probes with potentially beneficial pharmacological profiles.
Collapse
Affiliation(s)
- Saheem A Zaidi
- Department of Quantitative and Computational Biology, Bridge Institute, USC Michelson Center for Convergent Biosciences, University of Southern California, Los Angeles, CA, USA
| | - Vsevolod Katritch
- Department of Quantitative and Computational Biology, Bridge Institute, USC Michelson Center for Convergent Biosciences, University of Southern California, Los Angeles, CA, USA. .,Department of Chemistry, Bridge Institute, USC Michelson Center for Convergent Biosciences, University of Southern California, Los Angeles, CA, USA.
| |
Collapse
|
3
|
Reed B, Butelman ER, Kreek MJ. Kappa Opioid Receptor Antagonists as Potential Therapeutics for Mood and Substance Use Disorders. Handb Exp Pharmacol 2020; 271:473-491. [PMID: 33174064 DOI: 10.1007/164_2020_401] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The kappa opioid receptor (KOR) and its primary cognate ligands, the dynorphin peptides, are involved in diverse physiological processes. Disruptions to the KOR/dynorphin system have been found to likely play a role in multiple neuropsychological disorders, and hence KOR has emerged as a potential therapeutic target. Targeting KOR is complicated by close homology to the mu and delta opioid receptors (MOR and DOR), and many KOR ligands have at least moderate affinity to MOR and/or DOR. Animal models utilizing primarily very long-lasting selective KOR antagonists (>3 weeks following a single dose) have demonstrated that KOR antagonism attenuates certain anxiety-like and depression-like behaviors and blocks stress- and cue-induced reinstatement to drug seeking. Recently, relatively selective KOR antagonists with medication-like pharmacokinetic and pharmacodynamic properties and durations of action have been developed. One of these, JNJ-67953964 (also referred to as CERC-501, LY2456302, OpraKappa or Aticaprant) has been studied in humans, and shown to be safe, relatively KOR selective, and able to substantially attenuate binding of a KOR PET tracer to CNS localized KOR for greater than 24 h. While animal studies have indicated that compounds of this structural class are capable of normalizing withdrawal signs in animal models of cocaine and alcohol dependence and reducing cocaine and alcohol intake/seeking, additional studies are needed to determine the value of these second generation KOR antagonists in treating mood disorders and substance use disorders in humans.
Collapse
Affiliation(s)
- Brian Reed
- Laboratory of the Biology of Addictive Diseases, The Rockefeller University, New York, NY, USA.
| | - Eduardo R Butelman
- Laboratory of the Biology of Addictive Diseases, The Rockefeller University, New York, NY, USA
| | - Mary Jeanne Kreek
- Laboratory of the Biology of Addictive Diseases, The Rockefeller University, New York, NY, USA
| |
Collapse
|
4
|
Ferré G, Czaplicki G, Demange P, Milon A. Structure and dynamics of dynorphin peptide and its receptor. VITAMINS AND HORMONES 2019; 111:17-47. [DOI: 10.1016/bs.vh.2019.05.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
|
5
|
Che T, Majumdar S, Zaidi SA, Ondachi P, McCorvy JD, Wang S, Mosier PD, Uprety R, Vardy E, Krumm BE, Han GW, Lee MY, Pardon E, Steyaert J, Huang XP, Strachan RT, Tribo AR, Pasternak GW, Carroll FI, Stevens RC, Cherezov V, Katritch V, Wacker D, Roth BL. Structure of the Nanobody-Stabilized Active State of the Kappa Opioid Receptor. Cell 2018; 172:55-67.e15. [PMID: 29307491 DOI: 10.1016/j.cell.2017.12.011] [Citation(s) in RCA: 268] [Impact Index Per Article: 44.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 10/11/2017] [Accepted: 12/06/2017] [Indexed: 10/18/2022]
Abstract
The κ-opioid receptor (KOP) mediates the actions of opioids with hallucinogenic, dysphoric, and analgesic activities. The design of KOP analgesics devoid of hallucinatory and dysphoric effects has been hindered by an incomplete structural and mechanistic understanding of KOP agonist actions. Here, we provide a crystal structure of human KOP in complex with the potent epoxymorphinan opioid agonist MP1104 and an active-state-stabilizing nanobody. Comparisons between inactive- and active-state opioid receptor structures reveal substantial conformational changes in the binding pocket and intracellular and extracellular regions. Extensive structural analysis and experimental validation illuminate key residues that propagate larger-scale structural rearrangements and transducer binding that, collectively, elucidate the structural determinants of KOP pharmacology, function, and biased signaling. These molecular insights promise to accelerate the structure-guided design of safer and more effective κ-opioid receptor therapeutics.
Collapse
Affiliation(s)
- Tao Che
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Susruta Majumdar
- Molecular Pharmacology Program and Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Saheem A Zaidi
- Department of Biological Sciences, Bridge Institute, University of Southern California, Los Angeles, CA 90089, USA
| | - Pauline Ondachi
- Center for Organic and Medicinal Chemistry, Research Triangle Institute, Research Triangle Park, NC 27709, USA
| | - John D McCorvy
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Sheng Wang
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Philip D Mosier
- Department of Medicinal Chemistry and Institute for Structural Biology, Drug Discovery and Development, Virginia Commonweath University, Richmond, VA 23298, USA
| | - Rajendra Uprety
- Molecular Pharmacology Program and Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Eyal Vardy
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Brian E Krumm
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Gye Won Han
- Department of Chemistry, Bridge Institute, University of Southern California, Los Angeles, CA 90089, USA
| | - Ming-Yue Lee
- Department of Chemistry, Bridge Institute, University of Southern California, Los Angeles, CA 90089, USA; School of Molecular Sciences, Biodesign Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA; Institute of Natural Resources and Environmental Audits, Nanjing Audit University, Nanjing, China
| | - Els Pardon
- Structural Biology Brussels, Vrije Universiteit Brussel, 1050 Brussels, Belgium; VIB-VUB Center for Structural Biology, VIB, 1050 Brussels, Belgium
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussel, 1050 Brussels, Belgium; VIB-VUB Center for Structural Biology, VIB, 1050 Brussels, Belgium
| | - Xi-Ping Huang
- National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), School of Medicine, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Ryan T Strachan
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Alexandra R Tribo
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Gavril W Pasternak
- Molecular Pharmacology Program and Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - F Ivy Carroll
- Center for Organic and Medicinal Chemistry, Research Triangle Institute, Research Triangle Park, NC 27709, USA
| | - Raymond C Stevens
- Department of Biological Sciences, Bridge Institute, University of Southern California, Los Angeles, CA 90089, USA; Department of Chemistry, Bridge Institute, University of Southern California, Los Angeles, CA 90089, USA
| | - Vadim Cherezov
- Department of Chemistry, Bridge Institute, University of Southern California, Los Angeles, CA 90089, USA
| | - Vsevolod Katritch
- Department of Biological Sciences, Bridge Institute, University of Southern California, Los Angeles, CA 90089, USA; Department of Chemistry, Bridge Institute, University of Southern California, Los Angeles, CA 90089, USA
| | - Daniel Wacker
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA.
| | - Bryan L Roth
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), School of Medicine, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| |
Collapse
|
6
|
Journigan VB, Polgar WE, Tuan EW, Lu J, Daga PR, Zaveri NT. Probing ligand recognition of the opioid pan antagonist AT-076 at nociceptin, kappa, mu, and delta opioid receptors through structure-activity relationships. Sci Rep 2017; 7:13255. [PMID: 29038479 PMCID: PMC5643385 DOI: 10.1038/s41598-017-13129-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 09/18/2017] [Indexed: 11/15/2022] Open
Abstract
Few opioid ligands binding to the three classic opioid receptor subtypes, mu, kappa and delta, have high affinity at the fourth opioid receptor, the nociceptin/orphanin FQ receptor (NOP). We recently reported the discovery of AT-076 (1), (R)-7-hydroxy-N-((S)-1-(4-(3-hydroxyphenyl)piperidin-1-yl)-3-methylbutan-2-yl)-1,2,3,4-tetrahydroisoquinoline-3-carboxamide, a pan antagonist with nanomolar affinity for all four subtypes. Since AT-076 binds with high affinity at all four subtypes, we conducted a structure-activity relationship (SAR) study to probe ligand recognition features important for pan opioid receptor activity, using chemical modifications of key pharmacophoric groups. SAR analysis of the resulting analogs suggests that for the NOP receptor, the entire AT-076 scaffold is crucial for high binding affinity, but the binding mode is likely different from that of NOP antagonists C-24 and SB-612111 bound in the NOP crystal structure. On the other hand, modifications of the 3-hydroxyphenyl pharmacophore, but not the 7-hydroxy Tic pharmacophore, are better tolerated at kappa and mu receptors and yield very high affinity multifunctional (e.g. 12) or highly selective (e.g. 16) kappa ligands. With the availability of the opioid receptor crystal structures, our SAR analysis of the common chemotype of AT-076 suggests rational approaches to modulate binding selectivity, enabling the design of multifunctional or selective opioid ligands from such scaffolds.
Collapse
MESH Headings
- Humans
- Narcotic Antagonists/chemistry
- Narcotic Antagonists/pharmacology
- Opioid Peptides/chemistry
- Receptors, Opioid/chemistry
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, delta/chemistry
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/chemistry
- Receptors, Opioid, mu/antagonists & inhibitors
- Receptors, Opioid, mu/chemistry
- Structure-Activity Relationship
- Nociceptin
Collapse
Affiliation(s)
- V Blair Journigan
- Astraea Therapeutics, 320 Logue Avenue, Suite 142, Mountain View, CA, 94043, USA
- Marshall University School of Pharmacy, Department of Pharmaceutical Sciences, One John Marshall Drive, Huntington, WV 25755, USA
| | - Willma E Polgar
- Astraea Therapeutics, 320 Logue Avenue, Suite 142, Mountain View, CA, 94043, USA
| | - Edward W Tuan
- Astraea Therapeutics, 320 Logue Avenue, Suite 142, Mountain View, CA, 94043, USA
| | - James Lu
- Astraea Therapeutics, 320 Logue Avenue, Suite 142, Mountain View, CA, 94043, USA
| | - Pankaj R Daga
- Astraea Therapeutics, 320 Logue Avenue, Suite 142, Mountain View, CA, 94043, USA
| | - Nurulain T Zaveri
- Astraea Therapeutics, 320 Logue Avenue, Suite 142, Mountain View, CA, 94043, USA.
| |
Collapse
|
7
|
Vardy E, Robinson JE, Li C, Olsen RHJ, DiBerto JF, Giguere PM, Sassano FM, Huang XP, Zhu H, Urban DJ, White KL, Rittiner JE, Crowley NA, Pleil KE, Mazzone CM, Mosier PD, Song J, Kash TL, Malanga CJ, Krashes MJ, Roth BL. A New DREADD Facilitates the Multiplexed Chemogenetic Interrogation of Behavior. Neuron 2015; 86:936-946. [PMID: 25937170 DOI: 10.1016/j.neuron.2015.03.065] [Citation(s) in RCA: 250] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 03/02/2015] [Accepted: 03/29/2015] [Indexed: 01/09/2023]
Abstract
DREADDs are chemogenetic tools widely used to remotely control cellular signaling, neuronal activity, and behavior. Here we used a structure-based approach to develop a new Gi-coupled DREADD using the kappa-opioid receptor as a template (KORD) that is activated by the pharmacologically inert ligand salvinorin B (SALB). Activation of virally expressed KORD in several neuronal contexts robustly attenuated neuronal activity and modified behaviors. Additionally, co-expression of the KORD and the Gq-coupled M3-DREADD within the same neuronal population facilitated the sequential and bidirectional remote control of behavior. The availability of DREADDs activated by different ligands provides enhanced opportunities for investigating diverse physiological systems using multiplexed chemogenetic actuators.
Collapse
Affiliation(s)
- Eyal Vardy
- Department of Pharmacology and National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), University of North Carolina School of Medicine, Chapel Hill, NC 27514, USA
| | - J Elliott Robinson
- Neurology Department, University of North Carolina School of Medicine, Chapel Hill, NC 27514, USA; Curriculum in Neurobiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA; Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Chia Li
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA; National Institute of Drug Abuse, Baltimore, MD 21224, USA
| | - Reid H J Olsen
- Department of Pharmacology and National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), University of North Carolina School of Medicine, Chapel Hill, NC 27514, USA; Curriculum in Neurobiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Jeffrey F DiBerto
- Neurology Department, University of North Carolina School of Medicine, Chapel Hill, NC 27514, USA
| | - Patrick M Giguere
- Department of Pharmacology and National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), University of North Carolina School of Medicine, Chapel Hill, NC 27514, USA
| | - Flori M Sassano
- Department of Pharmacology and National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), University of North Carolina School of Medicine, Chapel Hill, NC 27514, USA
| | - Xi-Ping Huang
- Department of Pharmacology and National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), University of North Carolina School of Medicine, Chapel Hill, NC 27514, USA
| | - Hu Zhu
- Department of Pharmacology and National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), University of North Carolina School of Medicine, Chapel Hill, NC 27514, USA
| | - Daniel J Urban
- Department of Pharmacology and National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), University of North Carolina School of Medicine, Chapel Hill, NC 27514, USA
| | - Kate L White
- Department of Pharmacology and National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), University of North Carolina School of Medicine, Chapel Hill, NC 27514, USA
| | - Joseph E Rittiner
- Curriculum in Neurobiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Nicole A Crowley
- Department of Pharmacology and National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), University of North Carolina School of Medicine, Chapel Hill, NC 27514, USA; Curriculum in Neurobiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA; Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Kristen E Pleil
- Department of Pharmacology and National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), University of North Carolina School of Medicine, Chapel Hill, NC 27514, USA; Curriculum in Neurobiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA; Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Christopher M Mazzone
- Department of Pharmacology and National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), University of North Carolina School of Medicine, Chapel Hill, NC 27514, USA; Curriculum in Neurobiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA; Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Philip D Mosier
- Department of Medicinal Chemistry, Virginia Commonwealth University School of Pharmacy, Richmond, VA 23298, USA
| | - Juan Song
- Department of Pharmacology and National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), University of North Carolina School of Medicine, Chapel Hill, NC 27514, USA; Curriculum in Neurobiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Thomas L Kash
- Department of Pharmacology and National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), University of North Carolina School of Medicine, Chapel Hill, NC 27514, USA; Curriculum in Neurobiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA; Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - C J Malanga
- Neurology Department, University of North Carolina School of Medicine, Chapel Hill, NC 27514, USA; Curriculum in Neurobiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA; Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Michael J Krashes
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA; National Institute of Drug Abuse, Baltimore, MD 21224, USA.
| | - Bryan L Roth
- Department of Pharmacology and National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), University of North Carolina School of Medicine, Chapel Hill, NC 27514, USA; Curriculum in Neurobiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.
| |
Collapse
|
8
|
K303⁶·⁵⁸ in the μ opioid (MOP) receptor is important in conferring selectivity for covalent binding of β-funaltrexamine (β-FNA). Eur J Pharmacol 2014; 748:93-100. [PMID: 25481857 DOI: 10.1016/j.ejphar.2014.11.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 11/17/2014] [Accepted: 11/25/2014] [Indexed: 11/23/2022]
Abstract
β-funaltrexamine (β-FNA) is an irreversible μ opioid (MOP) receptor antagonist and a reversible agonist of κ opioid (KOP) receptor. β-FNA binds covalently to the MOP receptor at Lys233(5.39), which is conserved among opioid receptors. Molecular docking of β-FNA showed that K303(6.58) in the MOP receptor and E297(6.58) in the KOP receptor played distinct roles in positioning β-FNA. K303(6.58)E MOP receptor and E297(6.58)K KOP receptor mutants were generated. The mutations did not affect β-FNA affinity or efficacy. K303(6.58)E mutation in the MOP receptor greatly reduced covalent binding of [(3)H]β-FNA; however, E297(6.58)K did not enable the KOP receptor to bind irreversibly to β-FNA. Molecular modeling demonstrated that the ε-amino group of K303(6.58) in the MOP receptor interacted with CO of the acetate group of β-FNA to facilitate covalent bond formation with Lys233(5.39). Replacement of K303(6.58) with Glu in the MOP receptor resulted in repulsion between the COOH of Glu and the CO of β-FNA and increased the distance between K233(5.39) and the fumarate group, making it impossible for covalent bond formation. These findings will be helpful for design of selective non-peptide MOP receptor antagonists.
Collapse
|
9
|
Vardy E, Mosier PD, Frankowski KJ, Wu H, Katritch V, Westkaemper RB, Aubé J, Stevens RC, Roth BL. Chemotype-selective modes of action of κ-opioid receptor agonists. J Biol Chem 2013; 288:34470-83. [PMID: 24121503 DOI: 10.1074/jbc.m113.515668] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The crystal structures of opioid receptors provide a novel platform for inquiry into opioid receptor function. The molecular determinants for activation of the κ-opioid receptor (KOR) were studied using a combination of agonist docking, functional assays, and site-directed mutagenesis. Eighteen positions in the putative agonist binding site of KOR were selected and evaluated for their effects on receptor binding and activation by ligands representing four distinct chemotypes: the peptide dynorphin A(1-17), the arylacetamide U-69593, and the non-charged ligands salvinorin A and the octahydroisoquinolinone carboxamide 1xx. Minimally biased docking of the tested ligands into the antagonist-bound KOR structure generated distinct binding modes, which were then evaluated biochemically and pharmacologically. Our analysis identified two types of mutations: those that affect receptor function primarily via ligand binding and those that primarily affect function. The shared and differential mechanisms of agonist binding and activation in KOR are further discussed. Usually, mutations affecting function more than binding were located at the periphery of the binding site and did not interact strongly with the various ligands. Analysis of the crystal structure along with the present results provide fundamental insights into the activation mechanism of the KOR and suggest that "functional" residues, along with water molecules detected in the crystal structure, may be directly involved in transduction of the agonist binding event into structural changes at the conserved rotamer switches, thus leading to receptor activation.
Collapse
Affiliation(s)
- Eyal Vardy
- From the Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599
| | | | | | | | | | | | | | | | | |
Collapse
|
10
|
A DFT and semiempirical model-based study of opioid receptor affinity and selectivity in a group of molecules with a morphine structural core. INTERNATIONAL JOURNAL OF MEDICINAL CHEMISTRY 2012; 2012:682495. [PMID: 25379287 PMCID: PMC4207423 DOI: 10.1155/2012/682495] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 09/20/2012] [Indexed: 12/12/2022]
Abstract
We report the results of a search for model-based relationships between mu, delta, and kappa opioid receptor binding affinity and molecular structure for a group of molecules having in common a morphine structural core. The wave functions and local reactivity indices were obtained at the ZINDO/1 and B3LYP/6-31G∗∗ levels of theory for comparison. New developments in the expression for the drug-receptor interaction energy expression allowed several local atomic reactivity indices to be included, such as local electronic chemical potential, local hardness, and local electrophilicity. These indices, together with a new proposal for the ordering of the independent variables, were incorporated in the statistical study. We found and discussed several statistically significant relationships for mu, delta, and kappa opioid receptor binding affinity at both levels of theory. Some of the new local reactivity indices incorporated in the theory appear in several equations for the first time in the history of model-based equations. Interaction pharmacophores were generated for mu, delta, and kappa receptors. We discuss possible differences regulating binding and selectivity in opioid receptor subtypes. This study, contrarily to the statistically backed ones, is able to provide a microscopic insight of the mechanisms involved in the binding process.
Collapse
|
11
|
Ślusarz MJ. Molecular modeling study of the opioid receptor interactions with series of cyclic deltorphin analogues. J Pept Sci 2011; 17:554-64. [DOI: 10.1002/psc.1371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Revised: 02/18/2011] [Accepted: 02/21/2011] [Indexed: 11/08/2022]
|
12
|
Cunningham CW, Rothman RB, Prisinzano TE. Neuropharmacology of the naturally occurring kappa-opioid hallucinogen salvinorin A. Pharmacol Rev 2011; 63:316-47. [PMID: 21444610 DOI: 10.1124/pr.110.003244] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Salvia divinorum is a perennial sage native to Oaxaca, Mexico, that has been used traditionally in divination rituals and as a treatment for the "semimagical" disease panzón de borrego. Because of the intense "out-of-body" experiences reported after inhalation of the pyrolized smoke, S. divinorum has been gaining popularity as a recreational hallucinogen, and the United States and several other countries have regulated its use. Early studies isolated the neoclerodane diterpene salvinorin A as the principal psychoactive constituent responsible for these hallucinogenic effects. Since the finding that salvinorin A exerts its potent psychotropic actions through the activation of KOP receptors, there has been much interest in elucidating the underlying mechanisms behind its effects. These effects are particularly remarkable, because 1) salvinorin A is the first reported non-nitrogenous opioid receptor agonist, and 2) its effects are not mediated by the 5-HT(2A) receptor, the classic target of hallucinogens such as lysergic acid diethylamide and mescaline. Rigorous investigation into the structural features of salvinorin A responsible for opioid receptor affinity and selectivity has produced numerous receptor probes, affinity labels, and tools for evaluating the biological processes responsible for its observed psychological effects. Salvinorin A has therapeutic potential as a treatment for pain, mood and personality disorders, substance abuse, and gastrointestinal disturbances, and suggests that nonalkaloids are potential scaffolds for drug development for aminergic G-protein coupled receptors.
Collapse
|
13
|
Runyon SP, Brieaddy LE, Mascarella SW, Thomas JB, Navarro HA, Howard JL, Pollard GT, Carroll FI. Analogues of (3R)-7-hydroxy-N-[(1S)-1-{[(3R,4R)-4-(3-hydroxyphenyl)-3,4-dimethyl-1-piperidinyl]methyl}-2-methylpropyl)-1,2,3,4-tetrahydro-3-isoquinolinecarboxamide (JDTic). Synthesis and in vitro and in vivo opioid receptor antagonist activity. J Med Chem 2010; 53:5290-301. [PMID: 20568781 DOI: 10.1021/jm1004978] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis of compounds 6, 7a,b, 8a,b, 9a,b, and 10a,b where the amino -NH- group of JDTic (3) was replaced with an aromatic horizontal lineCH-, CH(2), O, S, or SO group was accomplished and used to further characterize the SAR of the compound 3 class of kappa opioid receptor antagonists. All of the compounds showed subnanomolar to low nanomolar K(e) values at the kappa opioid receptor. The most potent compound was 7a, where the amino -NH- group of 3 was replaced by a methylene (-CH(2)-) group. This compound had a K(e) = 0.18 nM and was 37- and 248-fold selective for the kappa relative to the mu and delta opioid receptors, respectively. Similar to compound 3, compound 7a antagonized selective kappa agonist U50,488-induced diuresis after sc administration in rats. In contrast to 3, where kappa antagonist activity lasted for three weeks, compound 7a did not show any kappa antagonist activity after one week.
Collapse
Affiliation(s)
- Scott P Runyon
- Organic and Medicinal Chemistry, Research Triangle Institute, Research Triangle Park, North Carolina 27709, USA
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Fujii H, Osa Y, Ishihara M, Hanamura S, Nemoto T, Nakajima M, Hasebe K, Mochizuki H, Nagase H. Synthesis of N-isobutylnoroxymorphone from naltrexone by a selective cyclopropane ring opening reaction. Bioorg Med Chem Lett 2008; 18:4978-81. [DOI: 10.1016/j.bmcl.2008.08.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 08/05/2008] [Accepted: 08/08/2008] [Indexed: 10/21/2022]
|
15
|
|
16
|
Labuz D, Mousa SA, Schäfer M, Stein C, Machelska H. Relative contribution of peripheral versus central opioid receptors to antinociception. Brain Res 2007; 1160:30-8. [PMID: 17599812 DOI: 10.1016/j.brainres.2007.05.049] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Revised: 05/08/2007] [Accepted: 05/09/2007] [Indexed: 11/30/2022]
Abstract
Opioid effects are mediated by central and peripheral opioid receptors. Here we examine the relative contribution of each receptor population to antinociception elicited by systemically administered centrally penetrating opioids, and by loperamide (a peripherally restricted opioid). Nociception (abdominal writhes) was induced by intraperitoneally (i.p.) injected 0.6% acetic acid in mice. We analyzed opioid receptor expression in peritoneum by immunohistochemistry, antinociception after i.p. injected agonists at mu (morphine, loperamide)-, delta (SNC80)- and kappa (U50488)-receptors, and its reversibility by subcutaneously (s.c.) administered centrally penetrating antagonists beta-funaltrexamine (mu), naltrindole (delta) and nor-binaltorphimine (kappa), and by the peripherally restricted antagonist naloxone methiodide (NLXM). NLXM was also injected intracerebroventricularly (i.c.v.) before i.p. loperamide. Mu-, kappa- and, to a lesser degree, delta-receptors were expressed on peripheral nerve terminals in the peritoneum. The anatomical distribution of the opioid receptor staining was very similar to the staining for calcitonin gene-related peptide, a marker of sensory neurons. Morphine, U50488 and, to a lesser degree, SNC80 blocked acetic and acid induced writhes. These effects were reversed by beta-funaltrexamine, nor-binaltorphimine and naltrindole, respectively. NLXM (s.c.) reversed antinociceptive effects of morphine, SNC80 and U50488 by 57%, 80% and 47%, respectively. Loperamide (0.05 mg/kg)-induced antinociception was reversed by s.c. beta-funaltrexamine and NLXM. Loperamide (0.1 mg/kg)-induced antinociception was completely blocked by s.c. beta-funaltrexamine but was only attenuated (by 50%) by s.c. or i.c.v. NLXM. In conclusion, systemically administered centrally penetrating mu-, delta- and kappa-agonists produced a substantial part of antinociception through peripheral opioid receptors. Higher dose loperamide-induced antinociception involved also central opioid receptors.
Collapse
Affiliation(s)
- Dominika Labuz
- Klinik für Anaesthesiologie und operative Intensivmedizin, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, D-12200 Berlin, Germany
| | | | | | | | | |
Collapse
|
17
|
Kane BE, Nieto MJ, McCurdy CR, Ferguson DM. A unique binding epitope for salvinorin A, a non-nitrogenous kappa opioid receptor agonist. FEBS J 2006; 273:1966-74. [PMID: 16640560 DOI: 10.1111/j.1742-4658.2006.05212.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Salvinorin A is a potent kappa opioid receptor (KOP) agonist with unique structural and pharmacological properties. This non-nitrogenous ligand lacks nearly all the structural features commonly associated with opioid ligand binding and selectivity. This study explores the structural basis to salvinorin A binding and selectivity using a combination of chimeric and single-point mutant opioid receptors. The experiments were designed based on previous models of salvinorin A that locate the ligand within a pocket formed by transmembrane (TM) II, VI, and VII. More traditional sites of opioid recognition were also explored, including the highly conserved aspartate in TM III (D138) and the KOP selectivity site E297, to determine the role, if any, that these residues play in binding and selectivity. The results indicate that salvinorin A recognizes a cluster of residues in TM II and VII, including Q115, Y119, Y312, Y313, and Y320. Based on the position of these residues within the receptor, and prior study on salvinorin A, a model is proposed that aligns the ligand vertically, between TM II and VII. In this orientation, the ligand spans residues that are spaced one to two turns down the face of the helices within the receptor cavity. The ligand is also in close proximity to EL-2 which, based on chimeric data, is proposed to play an indirect role in salvinorin A binding and selectivity.
Collapse
MESH Headings
- Animals
- Binding Sites
- Cell Line
- Cells, Cultured
- Diterpenes/metabolism
- Diterpenes, Clerodane
- Epitope Mapping
- Epitopes/metabolism
- Humans
- Mice
- Mutagenesis, Site-Directed
- Point Mutation
- Rats
- Receptors, Opioid, delta/genetics
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/genetics
- Receptors, Opioid, kappa/metabolism
- Receptors, Opioid, mu/genetics
- Receptors, Opioid, mu/metabolism
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Salvia/chemistry
- Salvia/metabolism
Collapse
Affiliation(s)
- Brian E Kane
- Department of Medicinal Chemistry and Center for Drug Design, University of Minnesota, MN 55455, USA
| | | | | | | |
Collapse
|
18
|
Li W, Tang Y, Zheng YL, Qiu ZB. Molecular modeling and 3D-QSAR studies of indolomorphinan derivatives as kappa opioid antagonists. Bioorg Med Chem 2006; 14:601-10. [PMID: 16202615 DOI: 10.1016/j.bmc.2005.08.052] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2005] [Revised: 08/19/2005] [Accepted: 08/20/2005] [Indexed: 11/30/2022]
Abstract
Molecular modeling and 3D-QSAR studies were performed on 31 indolomorphinan derivatives to evaluate their antagonistic behaviors on kappa opioid receptor and provide information for further modification of this kind of compounds. Best predictions were obtained with CoMFA standard model (q2 = 0.693, N = 4, r2 = 0.900) and CoMSIA combined model (q2 = 0.617, N = 4, r2 = 0.904). Both models were further validated by an external test set of eight compounds with satisfactory predictions: r2 = 0.607 for CoMFA and r2 = 0.701 for CoMSIA. In addition, the 3D structure of human kappa opioid receptor was constructed based on the crystal structure of bovine rhodopsin, and the CoMSIA contour plots were then mapped into the structural model of kappa opioid receptor-GNTI complex to identify key residues, which might account for kappa antagonist potency and selectivity. The roles of nonconserved Glu297 and conserved Lys227 of human kappa opioid receptor were then discussed.
Collapse
Affiliation(s)
- Wei Li
- Department of Medicinal Chemistry, School of Pharmacy, Fudan University, Shanghai 200032, China
| | | | | | | |
Collapse
|
19
|
Watanabe A, Kai T, Nagase H. Novel Synthesis of the Ortho Ester Derivative of 4,5-Epoxymorphinan. Org Lett 2006; 8:523-6. [PMID: 16435875 DOI: 10.1021/ol052883a] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text]. A method was found for the novel synthesis of ortho ester derivatives that are potentially useful as selective epsilon opioid receptor ligands. An unexpected 17-(cyclopropylmethyl)-4,5alpha-epoxy-6alpha-hydroxy-3,7,7-trimethoxy-8-oxa-6,14-endoethanomorphinan was produced when 17-(cyclopropylmethyl)-4,5alpha-epoxy-3-methoxy-6alpha,14-dihydroxy-6beta-(1,3-dithia-2-yl)-morphinan was treated in methanol with trimethyl orthoformate and CuO/CuCl2. This ortho ester derivative was then converted to an ester with acid. The structure of the ortho ester was determined by 2D NMR (HMBC) and mass spectra.
Collapse
Affiliation(s)
- Akio Watanabe
- School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | | | | |
Collapse
|
20
|
Metcalf MD, Coop A. Kappa opioid antagonists: past successes and future prospects. AAPS JOURNAL 2005. [PMID: 16353947 DOI: 10.1208/aapsj070371].] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Antagonists of the kappa opioid receptor were initially investigated as pharmacological tools that would reverse the effects of kappa opioid receptor agonists. In the years following the discovery of the first selective kappa opioid antagonists, much information about their chemistry and pharmacology has been elicited and their potential therapeutic uses have been investigated. The review presents the current chemistry, ligand-based structure activity relationships, and pharmacology of the known nonpeptidic selective kappa opioid receptor antagonists. This manuscript endeavors to provide the reader with a useful reference of the investigations made to define the structure-activity relationships and pharmacology of selective kappa opioid receptor antagonists and their potential uses as pharmacological tools and as therapeutic agents in the treatment of disease states.
Collapse
Affiliation(s)
- Matthew D Metcalf
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 Penn Street, Baltimore, MD 21201, USA
| | | |
Collapse
|
21
|
Metcalf MD, Coop A. Kappa opioid antagonists: past successes and future prospects. AAPS J 2005. [PMID: 16353947 DOI: 10.1208/aapsj070371]] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Antagonists of the kappa opioid receptor were initially investigated as pharmacological tools that would reverse the effects of kappa opioid receptor agonists. In the years following the discovery of the first selective kappa opioid antagonists, much information about their chemistry and pharmacology has been elicited and their potential therapeutic uses have been investigated. The review presents the current chemistry, ligand-based structure activity relationships, and pharmacology of the known nonpeptidic selective kappa opioid receptor antagonists. This manuscript endeavors to provide the reader with a useful reference of the investigations made to define the structure-activity relationships and pharmacology of selective kappa opioid receptor antagonists and their potential uses as pharmacological tools and as therapeutic agents in the treatment of disease states.
Collapse
Affiliation(s)
- Matthew D Metcalf
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 Penn Street, Baltimore, MD 21201, USA
| | | |
Collapse
|
22
|
Metcalf MD, Coop A. Kappa opioid antagonists: past successes and future prospects. AAPS JOURNAL 2005; 7:E704-22. [PMID: 16353947 PMCID: PMC2751273 DOI: 10.1208/aapsj070371] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Antagonists of the kappa opioid receptor were initially investigated as pharmacological tools that would reverse the effects of kappa opioid receptor agonists. In the years following the discovery of the first selective kappa opioid antagonists, much information about their chemistry and pharmacology has been elicited and their potential therapeutic uses have been investigated. The review presents the current chemistry, ligand-based structure activity relationships, and pharmacology of the known nonpeptidic selective kappa opioid receptor antagonists. This manuscript endeavors to provide the reader with a useful reference of the investigations made to define the structure-activity relationships and pharmacology of selective kappa opioid receptor antagonists and their potential uses as pharmacological tools and as therapeutic agents in the treatment of disease states.
Collapse
Affiliation(s)
- Matthew D. Metcalf
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 Penn Street, 21201 Baltimore, MD
| | - Andrew Coop
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 Penn Street, 21201 Baltimore, MD
| |
Collapse
|
23
|
Pogozheva ID, Przydzial MJ, Mosberg HI. Homology modeling of opioid receptor-ligand complexes using experimental constraints. AAPS JOURNAL 2005; 7:E434-48. [PMID: 16353922 PMCID: PMC2750980 DOI: 10.1208/aapsj070243] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Opioid receptors interact with a variety of ligands, including endogenous peptides, opiates, and thousands of synthetic compounds with different structural scaffolds. In the absence of experimental structures of opioid receptors, theoretical modeling remains an important tool for structure-function analysis. The combination of experimental studies and modeling approaches allows development of realistic models of ligand-receptor complexes helpful for elucidation of the molecular determinants of ligand affinity and selectivity and for understanding mechanisms of functional agonism or antagonism. In this review we provide a brief critical assessment of the status of such theoretical modeling and describe some common problems and their possible solutions. Currently, there are no reliable theoretical methods to generate the models in a completely automatic fashion. Models of higher accuracy can be produced if homology modeling, based on the rhodopsin X-ray template, is supplemented by experimental structural constraints appropriate for the active or inactive receptor conformations, together with receptor-specific and ligand-specific interactions. The experimental constraints can be derived from mutagenesis and cross-linking studies, correlative replacements of ligand and receptor groups, and incorporation of metal binding sites between residues of receptors or receptors and ligands. This review focuses on the analysis of similarity and differences of the refined homology models of mu, delta, and kappa-opioid receptors in active and inactive states, emphasizing the molecular details of interaction of the receptors with some representative peptide and nonpeptide ligands, underlying the multiple modes of binding of small opiates, and the differences in binding modes of agonists and antagonists, and of peptides and alkaloids.
Collapse
Affiliation(s)
- Irina D Pogozheva
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, USA
| | | | | |
Collapse
|
24
|
Yan F, Mosier PD, Westkaemper RB, Stewart J, Zjawiony JK, Vortherms TA, Sheffler DJ, Roth BL. Identification of the molecular mechanisms by which the diterpenoid salvinorin A binds to kappa-opioid receptors. Biochemistry 2005; 44:8643-51. [PMID: 15952771 DOI: 10.1021/bi050490d] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Salvinorin A is a naturally occurring hallucinogenic diterpenoid from the plant Salvia divinorumthat selectively and potently activates kappa-opioid receptors (KORs). Salvinorin A is unique in that it is the only known lipid-like molecule that selectively and potently activates a G-protein coupled receptor (GPCR), which has as its endogenous agonist a peptide; salvinorin A is also the only known non-nitrogenous opioid receptor agonist. In this paper, we identify key residues in KORs responsible for the high binding affinity and agonist efficacy of salvinorin A. Surprisingly, we discovered that salvinorin A was stabilized in the binding pocket by interactions with tyrosine residues in helix 7 (Tyr313 and Tyr320) and helix 2 (Tyr119). Intriguingly, activation of KORs by salvinorin A required interactions with the helix 7 tyrosines Tyr312, Tyr313, and Tyr320 and with Tyr139 in helix 3. In contrast, the prototypical nitrogenous KOR agonist U69593 and the endogenous peptidergic agonist dynorphin A (1-13) showed differential requirements for these three residues for binding and activation. We also employed a novel approach, whereby we examined the effects of cysteine-substitution mutagenesis on the binding of salvinorin A and an analogue with a free sulfhydryl group, 2-thiosalvinorin B. We discovered that residues predicted to be in close proximity, especially Tyr313, to the free thiol of 2-thiosalvinorin B when mutated to Cys showed enhanced affinity for 2-thiosalvinorin B. When these findings are taken together, they imply that the diterpenoid salvinorin A utilizes unique residues within a commonly shared binding pocket to selectively activate KORs.
Collapse
Affiliation(s)
- Feng Yan
- Department of Biochemistry, Case Western Reserve University Medical School, Cleveland, Ohio 44106, USA
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Commiskey S, Fan LW, Ho IK, Rockhold RW. Butorphanol: effects of a prototypical agonist-antagonist analgesic on kappa-opioid receptors. J Pharmacol Sci 2005; 98:109-16. [PMID: 15942128 DOI: 10.1254/jphs.crj05001x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
The opioid analgesic, butorphanol (17-cyclobutylmethyl-3,14-dihydroxymorphinan) tartrate is a prototypical agonist-antagonist opioid analgesic agent whose potential for abuse has been the cause of litigation in the United States. With a published affinity for opioid receptors in vitro of 1:4:25 (mu:delta:kappa), the relative contribution of actions at each of these receptors to the in vivo actions of the drug are an issue of active investigation. A body of evidence has been developed which indicates that a substantial selective action of butorphanol on the kappa-opioid receptor mediates the development of tolerance to butorphanol and cross-tolerance to other opioid agonists; to the production of dependence upon butorphanol, particularly in the rodent; and to compensatory alterations in brain opioid receptor-effector systems. This perspective will identify the current state of understanding of the effects produced by butorphanol on brain opioid receptors, particularly on the kappa-opioid receptor subtype, and on the expression of phosphotyrosyl proteins following chronic treatment with butorphanol.
Collapse
Affiliation(s)
- Stephen Commiskey
- Department of Pharmacology & Toxicology, University of Mississippi Medical Center, Jackson, USA
| | | | | | | |
Collapse
|
26
|
Fowler CB, Pogozheva ID, Lomize AL, LeVine H, Mosberg HI. Complex of an active mu-opioid receptor with a cyclic peptide agonist modeled from experimental constraints. Biochemistry 2005; 43:15796-810. [PMID: 15595835 DOI: 10.1021/bi048413q] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Site-directed mutagenesis and design of Zn(2+)-binding centers have been used to determine a set of specific tertiary interactions between the mu-opioid receptor, a rhodopsin-like G protein-coupled receptor (GPCR), and its cyclic peptide agonist ligand, Tyr(1)-c(S-Et-S)[d-Cys(2)-Phe(3)-d-Pen(4)]NH(2) (JOM6). The binding affinity of the tetrapeptide is strongly dependent on the nature of its first and third residues and on substitutions at positions 213, 216, 237, 300, 315, and 318 of the mu-opioid receptor. His(1) and His(3) analogues of the ligand were able to form metal-binding complexes with the V300C and G213C/T315C receptor mutants, respectively. Direct contact of the Phe(3) residue of JOM6 with Gly(213), Asp(216), Thr(315), and Trp(318) of the receptor was suggested by the binding affinities of His(3)-, Nle(3)-, Leu(3)-, Aci(3)-, Delta(E)Phe(3)-, and Delta(Z)Phe(3)-substituted peptides with the G213C/T315C, D216V, T315C, and W318L mutants. The improved binding affinity of the free carboxylate analogue of JOM6 for binding to the E229D mutant revealed an interaction between the C-terminal group of the peptide and Glu(229) of the receptor. The experimental constraints that were obtained were applied for distance geometry modeling of the mu-receptor in complex with the tetrapeptide agonist ligand, JOM6. The active conformation of the opioid receptor was calculated using the crystal structure of "inactive" rhodopsin and published engineered and intrinsic metal-binding sites and disulfide bonds that allow or facilitate activation of GPCRs. Interhelical H-bonds existing in the mu-receptor were applied as additional distance constraints. The calculated model of the receptor-ligand complex can serve as a prototype of the active state for all rhodopsin-like GPCRs. It displays a strongly shifted transmembrane helix 6 (TM6) and reorientation of the conserved Trp(293) residue in TM6 upon its interaction with the agonist. Importantly, the binding pockets of the active and inactive states are not identical, which implies distinct interaction modes of agonists and antagonists. In the active state, the binding pocket of the mu-receptor is complementary to the previously proposed receptor-bound conformation of JOM6.
Collapse
MESH Headings
- Amino Acid Sequence
- Amino Acid Substitution/genetics
- Animals
- Binding Sites/genetics
- COS Cells
- Cattle
- Chlorocebus aethiops
- DNA Mutational Analysis
- Models, Molecular
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Peptides, Cyclic/chemistry
- Peptides, Cyclic/genetics
- Peptides, Cyclic/pharmacology
- Point Mutation/genetics
- Protein Conformation
- Rats
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/chemistry
- Receptors, Opioid, mu/genetics
- Zinc/metabolism
Collapse
Affiliation(s)
- Carol B Fowler
- Department of Medicinal Chemistry, University of Michigan, 428 Church Street, Ann Arbor, Michigan 48109-1065, USA
| | | | | | | | | |
Collapse
|
27
|
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.
Collapse
Affiliation(s)
- Maria Waldhoer
- Ernest Gallo Clinic and Research Center, University of California, San Francisco, Emeryville, California 94608, USA.
| | | | | |
Collapse
|
28
|
Bellucci F, Meini S, Cucchi P, Catalani C, Giuliani S, Zappitelli S, Rotondaro L, Quartara L, Giolitti A, Maggi CA. The N-terminal of Icatibant and bradykinin interact with the same Asp residues in the human B2 receptor. Eur J Pharmacol 2004; 491:121-5. [PMID: 15140628 DOI: 10.1016/j.ejphar.2004.03.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2004] [Accepted: 03/17/2004] [Indexed: 11/23/2022]
Abstract
The pharmacology of peptide and non-peptide bradykinin B2 receptor ligands was evaluated in the inositol phosphate (IP) production assay in CHO cells expressing the human bradykinin B2 receptor. The effect of single and double alanine mutation of D266 and D284 residues at the human bradykinin B2 receptor was evaluated on the agonist profile of bradykinin (H-Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg-OH) and the synthetic agonist FR190997 (8-[2,6-dichloro-3-[N-methylcarbamoyl)cinnamidoacetyl]-N-methylamino]benzyloxy]-2-methyl-4-(2-pyridylmethoxy)quinoline). Bradykinin potency (EC50 0.5 nM at the wild-type receptor) was reduced by 16-fold at D266A and D284A mutants and by 2300-fold at the D266A/D284A double mutant. None of the mutants affected the potency or the efficacy of FR190997. Peptide antagonists, Icatibant (H-DArg-Arg-Pro-Hyp-Gly-Thi-Ser-Dtic-Oic-Arg-OH) and MEN11270 (H-DArg-Arg-Pro-Hyp-Gly-Thi-c(Dab-DTic-Oic-Arg)c(7gamma-10alpha)) (100 nM) similarly antagonized the concentration-response curve to bradykinin or FR190997 (pA2 values 8.5 and 8.4 versus bradykinin and 8.2 and 8.4 versus FR190997) at the wild-type receptor. Non-peptide antagonists FR173657 ((E)-3-(6-acetamido-3-pyridyl)-N-[N-[2,4-dichloro-3-[(2-methyl-8-quinolinyl) oxymethyl]phenyl]-N-methylaminocarbonyl methyl]acrylamide) and LF16-0687 (1-[[2,4-dichloro-3-[(2,4-dimethylquinolin-8-yl)oxy] methyl]-phenyl]sulfonyl]-N-[3-[[4-(aminoiminomethyl)-phenyl]carbonylamino]propyl]-(S)-pyrrolidine carboxamide) (100 nM) showed an equivalent potency values in blocking the IP production induced by bradykinin or FR190997 (pA2 values 8.7 and 8.8 versus bradykinin and 8.8 and 8.6 versus FR190997). Whilst the antagonist potency of FR173657 and LF16-0687 was not affected by D266A/D284A double mutation (IP production induced by the synthetic agonist), that of Icatibant and MEN11270 was reduced by 50- and 200-fold. The antagonist potency of [Ala1]-Icatibant and [Ala2]-Icatibant (pA2 values at wild-type 7.7 and 6.4) was significantly less reduced (20-fold and 13-fold, respectively) by the D266A/D284A double mutation. Our results highlight a crucial role for two aspartic residues, D266 and D284, located at the top of transmembrane segments 6 and 7, in the high-affinity interaction of peptide antagonists with the human bradykinin B2 receptor. An interaction of these receptor residues with the N-terminal basic residues of Icatibant is hypothesized.
Collapse
Affiliation(s)
- Francesca Bellucci
- Department of Pharmacology, Menarini Ricerche S.p.A., via Rismondo 12A, 50131, Florence, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Thomas JB, Fix SE, Rothman RB, Mascarella SW, Dersch CM, Cantrell BE, Zimmerman DM, Carroll FI. Importance of phenolic address groups in opioid kappa receptor selective antagonists. J Med Chem 2004; 47:1070-3. [PMID: 14761209 DOI: 10.1021/jm030467v] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In vitro characterization and comparison of JDTic, its dehydroxy analogue and nor-BNI, and its dehydroxy analogue demonstrates that the N-substituted 3,4-dimethyl-(3-hydroxyphenyl)piperidine-derived antagonist, JDTic, relies more heavily on its phenol address group for affinity and antagonist activity relative to the corresponding naltrexone derived antagonists, nor-BNI. The structural flexibility of the former class of compound relative to the latter is postulated to underlie the difference.
Collapse
MESH Headings
- Animals
- Binding, Competitive
- Brain/metabolism
- In Vitro Techniques
- Naltrexone/analogs & derivatives
- Naltrexone/chemistry
- Naltrexone/pharmacology
- Phenols/chemistry
- Phenols/pharmacology
- Piperidines/chemistry
- Piperidines/pharmacology
- Radioligand Assay
- Rats
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/metabolism
- Receptors, Opioid, mu/antagonists & inhibitors
- Receptors, Opioid, mu/metabolism
- Structure-Activity Relationship
- Tetrahydroisoquinolines/chemistry
- Tetrahydroisoquinolines/pharmacology
Collapse
Affiliation(s)
- James B Thomas
- Chemistry and Life Sciences, Research Triangle Institute, Research Triangle Park, North Carolina 27709, USA
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Uwai K, Uchiyama H, Sakurada S, Kabuto C, Takeshita M. Syntheses and receptor-binding studies of derivatives of the opioid antagonist naltrexone. Bioorg Med Chem 2004; 12:417-21. [PMID: 14723960 DOI: 10.1016/j.bmc.2003.10.039] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Naltrexone (1), which is a member of the group of competitive opioid antagonists, shows a strong affinity for mu-receptors and its derivatives have been notable as novel receptor antagonists. In this paper, the preparation of several naltrexone derivatives is described; these were used to investigate the role of the oxygenated functional groups in facilitating binding to a series of the opioid receptors. The derivatives showed affinity for opioid mu-receptors which was similar to that of naltrexone, but these compounds, which had masked hydroxyl functional groups, displayed a moderate activity. These results suggest that every oxygenated functional group in naltrexone (1) plays an important role in binding to the opioid receptor.
Collapse
Affiliation(s)
- Koji Uwai
- Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, 981-8558 Sendai, Japan
| | | | | | | | | |
Collapse
|
31
|
Fan LW, Tien LT, Tanaka S, Sasaki K, Park Y, Ma T, Rockhold RW, Ho IK. Enhanced binding of nor-binaltorphimine to kappa-opioid receptors in rats dependent on butorphanol. J Neurosci Res 2003; 72:781-9. [PMID: 12774318 DOI: 10.1002/jnr.10578] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Autoradiographic characterization of binding for brain kappa(1) ([(3)H]CI-977) and kappa(2) ([(3)H]bremazocine) in the presence of DAMGO ([D-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin), DPDPE ([D-Pen(2), D-Pen(5)]-enkephalin), and U-69,593 opioid receptors, in the presence of different concentrations of a selective unlabeled kappa-opioid receptor antagonist, nor-binaltorphimine (nor-BNI), was performed in rats in which dependence on or withdrawal from butorphanol had been established. Dependence was induced by a 72 hr intracerebroventricular (i.c.v.) infusion with butorphanol (26 nmol/microl/hr; butorphanol dependent). Butorphanol withdrawal was produced by terminating the infusion of butorphanol in dependent animals. Responses were studied 7 hr following termination (butorphanol withdrawal). IC(50) values from competition studies were estimated by fitting inhibition curves for both kappa(1)- and kappa(2)-opioid receptor assays. In both dependent and withdrawal groups, the IC(50) values obtained against [(3)H]CI-977 or [(3)H]bremazocine with nor-BNI were decreased (ratios of approximately 0.03-0.21 and approximately 0.05-0.42 vs. control, respectively) in brain regions, including frontal cortex, nucleus accumbens, claustrum, dorsal endopiriform nucleus, caudate putamen, parietal cortex, posterior basolateral amygdaloid nucleus, dorsomedial hypothalamus, hippocampus, posterior paraventricular thalamic nucleus, periaqueductal gray, substantia nigra, superficial gray layer of the superior colliculus, ventral tegmental area, and locus coeruleus, compared with control. These results indicate that, in butorphanol-dependent and butorphanol-withdrawal rats, the brain kappa(1)- and kappa(2)-opioid receptors developed a supersensitivity to antagonist binding.
Collapse
Affiliation(s)
- Lir-Wan Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi 39216, USA
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Flippen-Anderson JL, Deschamps JR, George C, Hruby VJ, Misicka A, Lipkowski AW. Crystal structure of biphalin sulfate: a multireceptor opioid peptide. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 2002; 59:123-33. [PMID: 11985706 DOI: 10.1034/j.1399-3011.2002.01967.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Biphalin is a dimeric opioid peptide, composed of two tetrapeptides connected 'tail-to-tail', that exhibits a high affinity for all three opioid receptor types (i.e. mu, delta and kappa). This study presents the X-ray crystal structure of biphalin sulfate and compares it to other opioids that interact with the same biological targets. Both halves of the molecule have a folded backbone conformation but differ significantly from one another. Residues 1-4 in biphalin, which compare well with the delta selective opioid peptide DADLE, fold into a random coil. Residues 5-8, which can be fit to the mu selective peptide D-TIPP-NH2, exhibit a fairly normal type III' beta bend. Biphalin also exhibits structural similarities with two naltrexone analogs, naltrexonazine and norbinaltorphamine, that are specific to mu and kappa receptor sites.
Collapse
Affiliation(s)
- J L Flippen-Anderson
- Laboratory for the Structure of Matter, Naval Research Laboratory, Washington, DC 20375-5000, USA.
| | | | | | | | | | | |
Collapse
|
33
|
Portoghese PS. From models to molecules: opioid receptor dimers, bivalent ligands, and selective opioid receptor probes. J Med Chem 2001; 44:2259-69. [PMID: 11428919 DOI: 10.1021/jm010158+] [Citation(s) in RCA: 156] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
MESH Headings
- Amino Acid Sequence
- Binding Sites
- Dimerization
- Dynorphins/metabolism
- Ligands
- Models, Molecular
- Molecular Sequence Data
- Naltrexone/analogs & derivatives
- Naltrexone/metabolism
- Narcotic Antagonists
- Protein Structure, Secondary
- Receptors, Opioid/agonists
- Receptors, Opioid/chemistry
- Receptors, Opioid/metabolism
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/metabolism
- Structure-Activity Relationship
Collapse
Affiliation(s)
- P S Portoghese
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| |
Collapse
|
34
|
Chavkin C, McLaughlin JP, Celver JP. Regulation of opioid receptor function by chronic agonist exposure: constitutive activity and desensitization. Mol Pharmacol 2001; 60:20-5. [PMID: 11408596 DOI: 10.1124/mol.60.1.20] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- C Chavkin
- Department of Pharmacology, University of Washington, Seattle, Washington 98195-7280, USA.
| | | | | |
Collapse
|
35
|
Metzger TG, Paterlini MG, Ferguson DM, Portoghese PS. Investigation of the selectivity of oxymorphone- and naltrexone-derived ligands via site-directed mutagenesis of opioid receptors: exploring the "address" recognition locus. J Med Chem 2001; 44:857-62. [PMID: 11300867 DOI: 10.1021/jm000381r] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The delta-selective opioid antagonist naltrindole (NTI), as well as the kappa-selective opioid antagonists norbinaltorphimine (norBNI) and 5'-guanidinonaltrindole (GNTI), are derived from naltrexone, a universal opioid antagonist. Previous studies have indicated that extracellular loop III is the key region for discrimination by naltrexone-derived selective ligands between the delta, mu, and kappa opioid receptor types. It has been proposed that selective ligands could bind to all three receptor types if the appropriate portions of the extracellular loops were eliminated. To investigate this possibility, several single-point mutant opioid receptors have been generated with the aim of conferring enhanced affinity of selective ligands for their nonpreferred receptor types. Mutations were made in all three types of opioid receptors with the focus on two positions at the extracellular end of transmembrane regions (TM) VI and VII. It was found that the delta-selective NTI could bind both mu and kappa receptors with significantly enhanced affinity when an aromatic residue in TM VII was replaced with alanine (mu[W318A] and kappa[Y312A]). Similarly, kappa-selective antagonists, norBNI and GNTI, showed enhanced affinity for the mu[W318A] mutant and for both mu and delta receptors when a glutamate residue was incorporated into the extracellular end of TM VI (mu[K303E] and delta[W284E]). These results demonstrate that naltrexone-derived selective ligands achieve their selectivity via a combination of enhanced affinity of the address for a particular subsite along with loss of affinity due to steric interference at nonpreferred types. The results reveal key residues in the "address" recognition locus that contribute to the selectivity of opioid ligands and support the hypothesis that recognition of the naltrexone moiety is essentially the same for all three receptor types.
Collapse
MESH Headings
- Amino Acid Sequence
- Base Sequence
- Binding, Competitive
- Cell Line
- Humans
- Ligands
- Models, Molecular
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Naltrexone/analogs & derivatives
- Naltrexone/metabolism
- Narcotic Antagonists
- Oxymorphone/analogs & derivatives
- Oxymorphone/metabolism
- Receptors, Opioid/agonists
- Receptors, Opioid/genetics
- Receptors, Opioid/metabolism
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, delta/genetics
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/genetics
- Receptors, Opioid, kappa/metabolism
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/antagonists & inhibitors
- Receptors, Opioid, mu/genetics
- Receptors, Opioid, mu/metabolism
Collapse
Affiliation(s)
- T G Metzger
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA
| | | | | | | |
Collapse
|