1
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Vass M, Podlewska S, de Esch IJP, Bojarski AJ, Leurs R, Kooistra AJ, de Graaf C. Aminergic GPCR-Ligand Interactions: A Chemical and Structural Map of Receptor Mutation Data. J Med Chem 2018; 62:3784-3839. [PMID: 30351004 DOI: 10.1021/acs.jmedchem.8b00836] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The aminergic family of G protein-coupled receptors (GPCRs) plays an important role in various diseases and represents a major drug discovery target class. Structure determination of all major aminergic subfamilies has enabled structure-based ligand design for these receptors. Site-directed mutagenesis data provides an invaluable complementary source of information for elucidating the structural determinants of binding of different ligand chemotypes. The current study provides a comparative analysis of 6692 mutation data points on 34 aminergic GPCR subtypes, covering the chemical space of 540 unique ligands from mutagenesis experiments and information from experimentally determined structures of 52 distinct aminergic receptor-ligand complexes. The integrated analysis enables detailed investigation of structural receptor-ligand interactions and assessment of the transferability of combined binding mode and mutation data across ligand chemotypes and receptor subtypes. An overview is provided of the possibilities and limitations of using mutation data to guide the design of novel aminergic receptor ligands.
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Affiliation(s)
- Márton Vass
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS) , VU University Amsterdam , 1081HZ Amsterdam , The Netherlands
| | - Sabina Podlewska
- Department of Medicinal Chemistry, Institute of Pharmacology , Polish Academy of Sciences , Smętna 12 , PL31-343 Kraków , Poland
| | - Iwan J P de Esch
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS) , VU University Amsterdam , 1081HZ Amsterdam , The Netherlands
| | - Andrzej J Bojarski
- Department of Medicinal Chemistry, Institute of Pharmacology , Polish Academy of Sciences , Smętna 12 , PL31-343 Kraków , Poland
| | - Rob Leurs
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS) , VU University Amsterdam , 1081HZ Amsterdam , The Netherlands
| | - Albert J Kooistra
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS) , VU University Amsterdam , 1081HZ Amsterdam , The Netherlands.,Department of Drug Design and Pharmacology , University of Copenhagen , Universitetsparken 2 , 2100 Copenhagen , Denmark
| | - Chris de Graaf
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS) , VU University Amsterdam , 1081HZ Amsterdam , The Netherlands.,Sosei Heptares , Steinmetz Building, Granta Park, Great Abington , Cambridge CB21 6DG , U.K
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2
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Ragusa G, Bencivenni S, Morales P, Callaway T, Hurst DP, Asproni B, Merighi S, Loriga G, Pinna GA, Reggio PH, Gessi S, Murineddu G. Synthesis, Pharmacological Evaluation, and Docking Studies of Novel Pyridazinone-Based Cannabinoid Receptor Type 2 Ligands. ChemMedChem 2018; 13:1102-1114. [PMID: 29575721 DOI: 10.1002/cmdc.201800152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Indexed: 11/12/2022]
Abstract
In recent years, cannabinoid type 2 receptors (CB2 R) have emerged as promising therapeutic targets in a wide variety of diseases. Selective ligands of CB2 R are devoid of the psychoactive effects typically observed for CB1 R ligands. Based on our recent studies on a class of pyridazinone 4-carboxamides, further structural modifications of the pyridazinone core were made to better investigate the structure-activity relationships for this promising scaffold with the aim to develop potent CB2 R ligands. In binding assays, two of the new synthesized compounds [6-(3,4-dichlorophenyl)-2-(4-fluorobenzyl)-cis-N-(4-methylcyclohexyl)-3-oxo-2,3-dihydropyridazine-4-carboxamide (2) and 6-(4-chloro-3-methylphenyl)-cis-N-(4-methylcyclohexyl)-3-oxo-2-pentyl-2,3-dihydropyridazine-4-carboxamide (22)] showed high CB2 R affinity, with Ki values of 2.1 and 1.6 nm, respectively. In addition, functional assays of these compounds and other new active related derivatives revealed their pharmacological profiles as CB2 R inverse agonists. Compound 22 displayed the highest CB2 R selectivity and potency, presenting a favorable in silico pharmacokinetic profile. Furthermore, a molecular modeling study revealed how 22 produces inverse agonism through blocking the movement of the toggle-switch residue, W6.48.
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Affiliation(s)
- Giulio Ragusa
- Department of Chemistry and Pharmacy, University of Sassari, via F. Muroni 23/A, 07100, Sassari, Italy
| | - Serena Bencivenni
- Dipartimento di Scienze Mediche, Sezione di Farmacologia, Università di Ferrara, Via Fossato di Mortara, 17-19, 44121, Ferrara, Italy
| | - Paula Morales
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, 27402, USA
| | - Tyra Callaway
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, 27402, USA
| | - Dow P Hurst
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, 27402, USA
| | - Battistina Asproni
- Department of Chemistry and Pharmacy, University of Sassari, via F. Muroni 23/A, 07100, Sassari, Italy
| | - Stefania Merighi
- Dipartimento di Scienze Mediche, Sezione di Farmacologia, Università di Ferrara, Via Fossato di Mortara, 17-19, 44121, Ferrara, Italy
| | - Giovanni Loriga
- Institute of Translational Pharmacology, National Research Council, 09010 Pula, Cagliari, Italy
| | - Gerard A Pinna
- Department of Chemistry and Pharmacy, University of Sassari, via F. Muroni 23/A, 07100, Sassari, Italy
| | - Patricia H Reggio
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, 27402, USA
| | - Stefania Gessi
- Dipartimento di Scienze Mediche, Sezione di Farmacologia, Università di Ferrara, Via Fossato di Mortara, 17-19, 44121, Ferrara, Italy
| | - Gabriele Murineddu
- Department of Chemistry and Pharmacy, University of Sassari, via F. Muroni 23/A, 07100, Sassari, Italy
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3
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Abstract
The Reggio group has constructed computer models of the inactive and G-protein-activated states of the cannabinoid CB1 and CB2 receptors, as well as, several orphan receptors that recognize a subset of cannabinoid compounds, including GPR55 and GPR18. These models have been used to design ligands, mutations, and covalent labeling studies. The resultant second-generation models have been used to design ligands with improved affinity, efficacy, and subtype selectivity. Herein, we provide a guide for the development of GPCR models using the most recent orphan receptor studied in our lab, GPR3. GPR3 is an orphan receptor that belongs to the Class A family of G-protein-coupled receptors. It shares high sequence similarity with GPR6, GPR12, the lysophospholipid receptors, and the cannabinoid receptors. GPR3 is predominantly expressed in mammalian brain and oocytes and it is known as a Gαs-coupled receptor activated constitutively in cells. GPR3 represents a possible target for the treatment of different pathological conditions such as Alzheimer's disease, oocyte maturation, or neuropathic pain. However, the lack of potent and selective GPR3 ligands is delaying the exploitation of this promising therapeutic target. In this context, we aim to develop a homology model that helps us to elucidate the structural determinants governing ligand-receptor interactions at GPR3. In this chapter, we detail the methods and rationale behind the construction of the GPR3 active-and inactive-state models. These homology models will enable the rational design of novel ligands, which may serve as research tools for further understanding of the biological role of GPR3.
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Affiliation(s)
- Paula Morales
- University of North Carolina at Greensboro, Greensboro, NC, United States.
| | - Dow P Hurst
- University of North Carolina at Greensboro, Greensboro, NC, United States
| | - Patricia H Reggio
- University of North Carolina at Greensboro, Greensboro, NC, United States
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4
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Morales P, Gómez-Cañas M, Navarro G, Hurst DP, Carrillo-Salinas FJ, Lagartera L, Pazos R, Goya P, Reggio PH, Guaza C, Franco R, Fernández-Ruiz J, Jagerovic N. Chromenopyrazole, a Versatile Cannabinoid Scaffold with in Vivo Activity in a Model of Multiple Sclerosis. J Med Chem 2016; 59:6753-6771. [PMID: 27309150 DOI: 10.1021/acs.jmedchem.6b00397] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A combination of molecular modeling and structure-activity relationship studies has been used to fine-tune CB2 selectivity in the chromenopyrazole ring, a versatile CB1/CB2 cannabinoid scaffold. Thus, a series of 36 new derivatives covering a wide range of structural diversity has been synthesized, and docking studies have been performed for some of them. Biological evaluation of the new compounds includes, among others, cannabinoid binding assays, functional studies, and surface plasmon resonance measurements. The most promising compound [43 (PM226)], a selective and potent CB2 agonist isoxazole derivative, was tested in the acute phase of Theiler's murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD), a well-established animal model of primary progressive multiple sclerosis. Compound 43 dampened neuroinflammation by reducing microglial activation in the TMEV.
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Affiliation(s)
- Paula Morales
- Instituto de Química Médica, Consejo Superior de Investigaciones Científicas, Calle Juan de la Cierva, 3, E-28006 Madrid, Spain
| | - María Gómez-Cañas
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense de Madrid, E-28040 Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), E-28040 Madrid, Spain
| | - Gemma Navarro
- Departamento de Bioquímica y Biología Molecular, Facultad de Biología, Universidad de Barcelona, E-08028 Barcelona, Spain
| | - Dow P Hurst
- Department of Chemistry and Biochemistry, University of North Carolina Greensboro, Greensboro, North Carolina 27402, United States
| | - Francisco J Carrillo-Salinas
- Grupo de Neuroinmunología Neurobiología Funcional y de Sistemas, Instituto Cajal, Consejo Superior de Investigaciones Científicas, E-28002 Madrid, Spain
| | - Laura Lagartera
- Instituto de Química Médica, Consejo Superior de Investigaciones Científicas, Calle Juan de la Cierva, 3, E-28006 Madrid, Spain
| | - Ruth Pazos
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense de Madrid, E-28040 Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), E-28040 Madrid, Spain
| | - Pilar Goya
- Instituto de Química Médica, Consejo Superior de Investigaciones Científicas, Calle Juan de la Cierva, 3, E-28006 Madrid, Spain
| | - Patricia H Reggio
- Department of Chemistry and Biochemistry, University of North Carolina Greensboro, Greensboro, North Carolina 27402, United States
| | - Carmen Guaza
- Grupo de Neuroinmunología Neurobiología Funcional y de Sistemas, Instituto Cajal, Consejo Superior de Investigaciones Científicas, E-28002 Madrid, Spain
| | - Rafael Franco
- Departamento de Bioquímica y Biología Molecular, Facultad de Biología, Universidad de Barcelona, E-08028 Barcelona, Spain
| | - Javier Fernández-Ruiz
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense de Madrid, E-28040 Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), E-28040 Madrid, Spain
| | - Nadine Jagerovic
- Instituto de Química Médica, Consejo Superior de Investigaciones Científicas, Calle Juan de la Cierva, 3, E-28006 Madrid, Spain
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5
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Hu J, Feng Z, Ma S, Zhang Y, Tong Q, Alqarni MH, Gou X, Xie XQ. Difference and Influence of Inactive and Active States of Cannabinoid Receptor Subtype CB2: From Conformation to Drug Discovery. J Chem Inf Model 2016; 56:1152-63. [PMID: 27186994 PMCID: PMC5395206 DOI: 10.1021/acs.jcim.5b00739] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Cannabinoid receptor 2 (CB2), a G protein-coupled receptor (GPCR), is a promising target for the treatment of neuropathic pain, osteoporosis, immune system, cancer, and drug abuse. The lack of an experimental three-dimensional CB2 structure has hindered not only the development of studies of conformational differences between the inactive and active CB2 but also the rational discovery of novel functional compounds targeting CB2. In this work, we constructed models of both inactive and active CB2 by homology modeling. Then we conducted two comparative 100 ns molecular dynamics (MD) simulations on the two systems-the active CB2 bound with both the agonist and G protein and the inactive CB2 bound with inverse agonist-to analyze the conformational difference of CB2 proteins and the key residues involved in molecular recognition. Our results showed that the inactive CB2 and the inverse agonist remained stable during the MD simulation. However, during the MD simulations, we observed dynamical details about the breakdown of the "ionic lock" between R131(3.50) and D240(6.30) as well as the outward/inward movements of transmembrane domains of the active CB2 that bind with G proteins and agonist (TM5, TM6, and TM7). All of these results are congruent with the experimental data and recent reports. Moreover, our results indicate that W258(6.48) in TM6 and residues in TM4 (V164(4.56)-L169(4.61)) contribute greatly to the binding of the agonist on the basis of the binding energy decomposition, while residues S180-F183 in extracellular loop 2 (ECL2) may be of importance in recognition of the inverse agonist. Furthermore, pharmacophore modeling and virtual screening were carried out for the inactive and active CB2 models in parallel. Among all 10 hits, two compounds exhibited novel scaffolds and can be used as novel chemical probes for future studies of CB2. Importantly, our studies show that the hits obtained from the inactive CB2 model mainly act as inverse agonist(s) or neutral antagonist(s) at low concentration. Moreover, the hit from the active CB2 model also behaves as a neutral antagonist at low concentration. Our studies provide new insight leading to a better understanding of the structural and conformational differences between two states of CB2 and illuminate the effects of structure on virtual screening and drug design.
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Affiliation(s)
- Jianping Hu
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, NIH National Center of Excellence for Computational Drug Abuse Research, Drug Discovery Institute, and Department of Computational Biology and Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
- College of Chemistry, Leshan Normal University, Leshan, Sichuan 614004, China
- School of Pharmacy and Bioengineering; Key Laboratory of Medicinal and Edible Plants Resources Development, Chengdu University, Chengdu, Sichuan 610106, China
| | - Zhiwei Feng
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, NIH National Center of Excellence for Computational Drug Abuse Research, Drug Discovery Institute, and Department of Computational Biology and Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Shifan Ma
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, NIH National Center of Excellence for Computational Drug Abuse Research, Drug Discovery Institute, and Department of Computational Biology and Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Yu Zhang
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, NIH National Center of Excellence for Computational Drug Abuse Research, Drug Discovery Institute, and Department of Computational Biology and Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Qin Tong
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, NIH National Center of Excellence for Computational Drug Abuse Research, Drug Discovery Institute, and Department of Computational Biology and Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Mohammed Hamed Alqarni
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, NIH National Center of Excellence for Computational Drug Abuse Research, Drug Discovery Institute, and Department of Computational Biology and Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Xiaojun Gou
- School of Pharmacy and Bioengineering; Key Laboratory of Medicinal and Edible Plants Resources Development, Chengdu University, Chengdu, Sichuan 610106, China
| | - Xiang-Qun Xie
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, NIH National Center of Excellence for Computational Drug Abuse Research, Drug Discovery Institute, and Department of Computational Biology and Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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6
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Picone RP, Kendall DA. Minireview: From the bench, toward the clinic: therapeutic opportunities for cannabinoid receptor modulation. Mol Endocrinol 2015; 29:801-13. [PMID: 25866875 DOI: 10.1210/me.2015-1062] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The effects of cannabinoids have been known for centuries and over the past several decades two G protein-coupled receptors, CB1 and CB2, that are responsible for their activity have been identified. Endogenous lipid-derived cannabinergic agents have been found, biosynthetic and catabolic machinery has been characterized, and synthetic agents have been designed to modulate these receptors. Selective agents including agonists, antagonists, inverse agonists, and novel allosteric modulators targeting either CB1 or CB2 have been developed to inhibit or augment their basal tone. As a result, the role these receptors play in human physiology and their potential therapeutic applications in disease states are being elucidated. The CB1 receptor, although ubiquitous, is densely expressed in the brain, and CB2 is largely found on cells of immune origin. This minireview highlights the role of CB1 in excitotoxic assaults in the brain and its potential to limit addiction liability. In addition, it will examine the relationship between receptor activity and stimulation of insulin release from pancreatic β-cells, insulin resistance, and feeding behavior leading toward obesity. The roles of CB2 in the neuropathology of amyotrophic lateral sclerosis and in the central manifestations of chronic HIV infection potentially converge at inflammatory cell activation, thereby providing an opportunity for intervention. Last, CB2 modulation is discussed in the context of an experimental model of postmenopausal osteoporosis. Achieving exquisite receptor selectivity and elucidating the mechanisms underlying receptor inhibition and activation will be essential for the development of the next generation of cannabinergic-based therapeutic agents.
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Affiliation(s)
- Robert P Picone
- Clinical Development (R.P.P.), Medical and Regulatory Affairs, Novo Nordisk Inc, Plainsboro, New Jersey 08536; and Department of Pharmaceutical Sciences (D.A.K.), University of Connecticut, Storrs, Connecticut 06269-3092
| | - Debra A Kendall
- Clinical Development (R.P.P.), Medical and Regulatory Affairs, Novo Nordisk Inc, Plainsboro, New Jersey 08536; and Department of Pharmaceutical Sciences (D.A.K.), University of Connecticut, Storrs, Connecticut 06269-3092
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7
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Lucchesi V, Hurst DP, Shore DM, Bertini S, Ehrmann BM, Allarà M, Lawrence L, Ligresti A, Minutolo F, Saccomanni G, Sharir H, Macchia M, Di Marzo V, Abood ME, Reggio PH, Manera C. CB2-selective cannabinoid receptor ligands: synthesis, pharmacological evaluation, and molecular modeling investigation of 1,8-Naphthyridin-2(1H)-one-3-carboxamides. J Med Chem 2014; 57:8777-91. [PMID: 25272206 PMCID: PMC4234427 DOI: 10.1021/jm500807e] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
![]()
We
have recently identified 1,8-naphthyridin-2(1H)-one-3-carboxamide
as a new scaffold very suitable for the development
of new CB2 receptor potent and selective ligands. In this paper we
describe a number of additional derivatives in which the same central
scaffold has been variously functionalized in position 1 or 6. All
new compounds showed high selectivity and affinity in the nanomolar
range for the CB2 receptor. Furthermore, we found that their functional
activity is controlled by the presence of the substituents at position
C-6 of the naphthyridine scaffold. In fact, the introduction of substituents
in this position determined a functionality switch from agonist to
antagonists/inverse agonists. Finally, docking studies showed that
the difference between the pharmacology of these ligands may be in
the ability/inability to block the Toggle Switch W6.48(258) (χ1 g+ → trans) transition.
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Affiliation(s)
- Valentina Lucchesi
- Dipartimento di Farmacia, Università di Pisa , Via Bonanno 6, 56126 Pisa, Italy
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8
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Feng Z, Alqarni MH, Yang P, Tong Q, Chowdhury A, Wang L, Xie XQ. Modeling, molecular dynamics simulation, and mutation validation for structure of cannabinoid receptor 2 based on known crystal structures of GPCRs. J Chem Inf Model 2014; 54:2483-99. [PMID: 25141027 PMCID: PMC4170816 DOI: 10.1021/ci5002718] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Indexed: 12/29/2022]
Abstract
The cannabinoid receptor 2 (CB2) plays an important role in the immune system. Although a few of GPCRs crystallographic structures have been reported, it is still challenging to obtain functional transmembrane proteins and high resolution X-ray crystal structures, such as for the CB2 receptor. In the present work, we used 10 reported crystal structures of GPCRs which had high sequence identities with CB2 to construct homology-based comparative CB2 models. We applied these 10 models to perform a prescreen by using a training set consisting of 20 CB2 active compounds and 980 compounds randomly selected from the National Cancer Institute (NCI) database. We then utilized the known 170 cannabinoid receptor 1 (CB1) or CB2 selective compounds for further validation. Based on the docking results, we selected one CB2 model (constructed by β1AR) that was most consistent with the known experimental data, revealing that the defined binding pocket in our CB2 model was well-correlated with the training and testing data studies. Importantly, we identified a potential allosteric binding pocket adjacent to the orthosteric ligand-binding site, which is similar to the reported allosteric pocket for sodium ion Na(+) in the A2AAR and the δ-opioid receptor. Our studies in correlation of our data with others suggested that sodium may reduce the binding affinities of endogenous agonists or its analogs to CB2. We performed a series of docking studies to compare the important residues in the binding pockets of CB2 with CB1, including antagonist, agonist, and our CB2 neutral compound (neutral antagonist) XIE35-1001. Then, we carried out 50 ns molecular dynamics (MD) simulations for the CB2 docked with SR144528 and CP55940, respectively. We found that the conformational changes of CB2 upon antagonist/agonist binding were congruent with recent reports of those for other GPCRs. Based on these results, we further examined one known residue, Val113(3.32), and predicted two new residues, Phe183 in ECL2 and Phe281(7.35), that were important for SR144528 and CP55940 binding to CB2. We then performed site-directed mutation experimental study for these residues and validated the predictions by radiometric binding affinity assay.
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Affiliation(s)
- Zhiwei Feng
- Department
of Pharmaceutical Sciences and Computational Chemical
Genomics Screening Center, School of Pharmacy, Computational Drug Abuse Research
Center, Drug Discovery Institute, and Department of Computational Biology and Department
of Structural Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Mohammed Hamed Alqarni
- Department
of Pharmaceutical Sciences and Computational Chemical
Genomics Screening Center, School of Pharmacy, Computational Drug Abuse Research
Center, Drug Discovery Institute, and Department of Computational Biology and Department
of Structural Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Peng Yang
- Department
of Pharmaceutical Sciences and Computational Chemical
Genomics Screening Center, School of Pharmacy, Computational Drug Abuse Research
Center, Drug Discovery Institute, and Department of Computational Biology and Department
of Structural Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Qin Tong
- Department
of Pharmaceutical Sciences and Computational Chemical
Genomics Screening Center, School of Pharmacy, Computational Drug Abuse Research
Center, Drug Discovery Institute, and Department of Computational Biology and Department
of Structural Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Ananda Chowdhury
- Department
of Pharmaceutical Sciences and Computational Chemical
Genomics Screening Center, School of Pharmacy, Computational Drug Abuse Research
Center, Drug Discovery Institute, and Department of Computational Biology and Department
of Structural Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Lirong Wang
- Department
of Pharmaceutical Sciences and Computational Chemical
Genomics Screening Center, School of Pharmacy, Computational Drug Abuse Research
Center, Drug Discovery Institute, and Department of Computational Biology and Department
of Structural Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Xiang-Qun Xie
- Department
of Pharmaceutical Sciences and Computational Chemical
Genomics Screening Center, School of Pharmacy, Computational Drug Abuse Research
Center, Drug Discovery Institute, and Department of Computational Biology and Department
of Structural Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
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9
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Alqarni M, Myint KZ, Tong Q, Yang P, Bartlow P, Wang L, Feng R, Xie XQ. Examining the critical roles of human CB2 receptor residues Valine 3.32 (113) and Leucine 5.41 (192) in ligand recognition and downstream signaling activities. Biochem Biophys Res Commun 2014; 452:334-9. [PMID: 25148941 DOI: 10.1016/j.bbrc.2014.08.048] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 08/11/2014] [Indexed: 11/19/2022]
Abstract
We performed molecular modeling and docking to predict a putative binding pocket and associated ligand-receptor interactions for human cannabinoid receptor 2 (CB2). Our data showed that two hydrophobic residues came in close contact with three structurally distinct CB2 ligands: CP-55,940, SR144528 and XIE95-26. Site-directed mutagenesis experiments and subsequent functional assays implicated the roles of Valine residue at position 3.32 (V113) and Leucine residue at position 5.41 (L192) in the ligand binding function and downstream signaling activities of the CB2 receptor. Four different point mutations were introduced to the wild type CB2 receptor: V113E, V113L, L192S and L192A. Our results showed that mutation of Val113 with a Glutamic acid and Leu192 with a Serine led to the complete loss of CB2 ligand binding as well as downstream signaling activities. Substitution of these residues with those that have similar hydrophobic side chains such as Leucine (V113L) and Alanine (L192A), however, allowed CB2 to retain both its ligand binding and signaling functions. Our modeling results validated by competition binding and site-directed mutagenesis experiments suggest that residues V113 and L192 play important roles in ligand binding and downstream signaling transduction of the CB2 receptor.
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Affiliation(s)
- Mohammed Alqarni
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, Pittsburgh, PA 15260, USA
| | - Kyaw Zeyar Myint
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, Pittsburgh, PA 15260, USA; Joint Carnegie Mellon University-University of Pittsburgh Ph.D. Program, Department of Computational Biology and Structural Biology, School of Medicine, Pittsburgh, PA 15260, USA
| | - Qin Tong
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, Pittsburgh, PA 15260, USA
| | - Peng Yang
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, Pittsburgh, PA 15260, USA
| | - Patrick Bartlow
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, Pittsburgh, PA 15260, USA
| | - Lirong Wang
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, Pittsburgh, PA 15260, USA
| | - Rentian Feng
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, Pittsburgh, PA 15260, USA
| | - Xiang-Qun Xie
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, Pittsburgh, PA 15260, USA; Joint Carnegie Mellon University-University of Pittsburgh Ph.D. Program, Department of Computational Biology and Structural Biology, School of Medicine, Pittsburgh, PA 15260, USA; Drug Discovery Institute, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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10
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Kimura T, Vukoti K, Lynch DL, Hurst DP, Grossfield A, Pitman MC, Reggio PH, Yeliseev AA, Gawrisch K. Global fold of human cannabinoid type 2 receptor probed by solid-state 13C-, 15N-MAS NMR and molecular dynamics simulations. Proteins 2013; 82:452-65. [PMID: 23999926 DOI: 10.1002/prot.24411] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 08/12/2013] [Accepted: 08/21/2013] [Indexed: 12/12/2022]
Abstract
The global fold of human cannabinoid type 2 (CB2 ) receptor in the agonist-bound active state in lipid bilayers was investigated by solid-state (13)C- and (15)N magic-angle spinning (MAS) NMR, in combination with chemical-shift prediction from a structural model of the receptor obtained by microsecond-long molecular dynamics (MD) simulations. Uniformly (13)C- and (15)N-labeled CB2 receptor was expressed in milligram quantities by bacterial fermentation, purified, and functionally reconstituted into liposomes. (13)C MAS NMR spectra were recorded without sensitivity enhancement for direct comparison of Cα, Cβ, and C=O bands of superimposed resonances with predictions from protein structures generated by MD. The experimental NMR spectra matched the calculated spectra reasonably well indicating agreement of the global fold of the protein between experiment and simulations. In particular, the (13) C chemical shift distribution of Cα resonances was shown to be very sensitive to both the primary amino acid sequence and the secondary structure of CB2. Thus the shape of the Cα band can be used as an indicator of CB2 global fold. The prediction from MD simulations indicated that upon receptor activation a rather limited number of amino acid residues, mainly located in the extracellular Loop 2 and the second half of intracellular Loop 3, change their chemical shifts significantly (≥ 1.5 ppm for carbons and ≥ 5.0 ppm for nitrogens). Simulated two-dimensional (13) Cα(i)-(13)C=O(i) and (13)C=O(i)-(15)NH(i + 1) dipolar-interaction correlation spectra provide guidance for selective amino acid labeling and signal assignment schemes to study the molecular mechanism of activation of CB2 by solid-state MAS NMR.
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Affiliation(s)
- Tomohiro Kimura
- Laboratory of Membrane Biochemistry and Biophysics, NIAAA, NIH, Bethesda, Maryland, 20892
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11
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Kotsikorou E, Navas F, Roche MJ, Gilliam AF, Thomas B, Seltzman HH, Kumar P, Song ZH, Hurst DP, Lynch DL, Reggio PH. The importance of hydrogen bonding and aromatic stacking to the affinity and efficacy of cannabinoid receptor CB2 antagonist, 5-(4-chloro-3-methylphenyl)-1-[(4-methylphenyl)methyl]-N-[(1S,2S,4R)-1,3,3-trimethylbicyclo[2.2.1]hept-2-yl]-1H-pyrazole-3-carboxamide (SR144528). J Med Chem 2013; 56:6593-612. [PMID: 23855811 PMCID: PMC3804063 DOI: 10.1021/jm400070u] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Despite the therapeutic promise of the subnanomolar affinity cannabinoid CB2 antagonist, 5-(4-chloro-3-methylphenyl)-1-[(4-methylphenyl)methyl]-N-[(1S,2S,4R)-1,3,3-trimethylbicyclo[2.2.1]hept-2-yl]-1H-pyrazole-3-carboxamide (SR144528, 1), little is known about its binding site interactions and no primary interaction site for 1 at CB2 has been identified. We report here the results of Glide docking studies in our cannabinoid CB2 inactive state model that were then tested via compound synthesis, binding, and functional assays. Our results show that the amide functional group of 1 is critical to its CB2 affinity and efficacy and that aromatic stacking interactions in the TMH5/6 aromatic cluster of CB2 are also important. Molecular modifications that increased the positive electrostatic potential in the region between the fenchyl and aromatic rings led to more efficacious compounds. This result is consistent with the EC-3 loop negatively charged amino acid, D275 (identified via Glide docking studies) acting as the primary interaction site for 1 and its analogues.
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Affiliation(s)
| | - Frank Navas
- Research Triangle Institute, Research Triangle Park, NC 27609
| | | | - Anne F. Gilliam
- Research Triangle Institute, Research Triangle Park, NC 27609
| | - Brian Thomas
- Research Triangle Institute, Research Triangle Park, NC 27609
| | | | - Pritesh Kumar
- Department of Pharmacology and Toxicology, University of Louisville, University of Louisville School of Medicine, Louisville, KY 40292
| | - Zhao-Hui Song
- Department of Pharmacology and Toxicology, University of Louisville, University of Louisville School of Medicine, Louisville, KY 40292
| | - Dow P. Hurst
- Center for Drug Discovery, Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402
| | - Diane L. Lynch
- Center for Drug Discovery, Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402
| | - Patricia H. Reggio
- Center for Drug Discovery, Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402
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12
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Renault N, Laurent X, Farce A, El Bakali J, Mansouri R, Gervois P, Millet R, Desreumaux P, Furman C, Chavatte P. Virtual Screening of CB2Receptor Agonists from Bayesian Network and High-Throughput Docking: Structural Insights into Agonist-Modulated GPCR Features. Chem Biol Drug Des 2013; 81:442-54. [DOI: 10.1111/cbdd.12095] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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13
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Kimura T, Yeliseev AA, Vukoti K, Rhodes SD, Cheng K, Rice KC, Gawrisch K. Recombinant cannabinoid type 2 receptor in liposome model activates g protein in response to anionic lipid constituents. J Biol Chem 2012; 287:4076-87. [PMID: 22134924 PMCID: PMC3281699 DOI: 10.1074/jbc.m111.268425] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Revised: 11/29/2011] [Indexed: 11/06/2022] Open
Abstract
Human cannabinoid type 2 (CB(2)) receptor expressed in Escherichia coli was purified and successfully reconstituted in the functional form into lipid bilayers composed of POPC, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine (POPS), and cholesteryl hemisuccinate (CHS). Reconstitution was performed by detergent removal from the protein/lipid/detergent mixed micelles either on an adsorbent column, or by rapid dilution to below the critical micelle concentration of detergent followed by removal of detergent monomers on a concentrator. Proteoliposomes prepared at a protein/phospholipid/CHS molar ratio of 1/620-650/210-220 are free of detergent as shown by (1)H NMR, have a homogeneous protein/lipid ratio shown by isopycnic gradient ultracentrifugation, and are small in size with a mean diameter of 150-200 nm as measured by dynamic light scattering. Functional integrity of the reconstituted receptor was confirmed by quantitative binding of (2)H-labeled agonist CP-55,940-d(6) measured by (2)H magic angle spinning NMR, as well as by activation of G protein. The efficiency of G protein activation by agonist-bound CB(2) receptor was affected by negative electric surface potentials of proteoliposomes controlled by the content of anionic CHS or POPS. The activation was highest at an anionic lipid content of about 50 mol %. There was no correlation between the efficiency of G protein activation and an increase of hydrocarbon chain order induced by CHS or cholesterol. The results suggest the importance of anionic lipids in regulating signal transduction by CB(2) receptor and other class A GPCR. The successful reconstitution of milligram quantities of pure, functional CB(2) receptor enables a wide variety of structural studies.
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Affiliation(s)
- Tomohiro Kimura
- From the Laboratory of Membrane Biochemistry and Biophysics, NIAAA, and
| | | | - Krishna Vukoti
- From the Laboratory of Membrane Biochemistry and Biophysics, NIAAA, and
| | - Steven D. Rhodes
- From the Laboratory of Membrane Biochemistry and Biophysics, NIAAA, and
| | - Kejun Cheng
- the Chemical Biology Research Branch, NIDA and NIAAA, National Institutes of Health, Bethesda, Maryland 20852
| | - Kenner C. Rice
- the Chemical Biology Research Branch, NIDA and NIAAA, National Institutes of Health, Bethesda, Maryland 20852
| | - Klaus Gawrisch
- From the Laboratory of Membrane Biochemistry and Biophysics, NIAAA, and
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14
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Cumella J, Hernández-Folgado L, Girón R, Sánchez E, Morales P, Hurst DP, Gómez-Cañas M, Gómez-Ruiz M, Pinto DCGA, Goya P, Reggio PH, Martin MI, Fernández-Ruiz J, Silva AMS, Jagerovic N. Chromenopyrazoles: non-psychoactive and selective CB₁ cannabinoid agonists with peripheral antinociceptive properties. ChemMedChem 2012; 7:452-63. [PMID: 22302767 DOI: 10.1002/cmdc.201100568] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 01/18/2012] [Indexed: 01/01/2023]
Abstract
The unwanted psychoactive effects of cannabinoid receptor agonists have limited their development as medicines. These CB₁-mediated side effects are due to the fact that CB₁ receptors are largely expressed in the central nervous system (CNS). As it is known that CB₁ receptors are also located peripherally, there is growing interest in targeting cannabinoid receptors located outside the brain. A library of chromenopyrazoles designed analogously to the classical cannabinoid cannabinol were synthesized, characterized, and tested for cannabinoid activity. Radioligand binding assays were used to determine their affinities at CB₁ and CB₂ receptors. Structural features required for CB₁/CB₂ affinity and selectivity were explored by molecular modeling. Some compounds in the chromenopyrazole series were observed to be selective CB₁ ligands. These modeling studies suggest that full CB₁ selectivity over CB₂ can be explained by the presence of a pyrazole ring in the structure. The functional activities of selected chromenopyrazoles were evaluated in isolated tissues. In vivo behavioral tests were then carried out on the most effective CB₁ cannabinoid agonist, 13 a. Chromenopyrazole 13 a did not induce modifications in any of the tested parameters on the mouse cannabinoid tetrad, thus discounting CNS-mediated effects. This lack of agonistic activity in the CNS suggests that this compound does not readily cross the blood-brain barrier. Moreover, 13 a can induce antinociception in a rat peripheral model of orofacial pain. Taking into account the negative results obtained with the hot-plate test, the antinociception induced by 13 a in the orofacial test could be mediated through peripheral mechanisms.
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Affiliation(s)
- Jose Cumella
- Instituto de Química Médica, CSIC, Juan de la Cierva 3, 28006 Madrid, Spain
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15
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Kotsikorou E, Madrigal KE, Hurst DP, Sharir H, Lynch DL, Heynen-Genel S, Milan LB, Chung TD, Seltzman HH, Bai Y, Caron MG, Barak L, Abood ME, Reggio PH. Identification of the GPR55 agonist binding site using a novel set of high-potency GPR55 selective ligands. Biochemistry 2011; 50:5633-47. [PMID: 21534610 PMCID: PMC3723401 DOI: 10.1021/bi200010k] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Marijuana is the most widely abused illegal drug, and its spectrum of effects suggests that several receptors are responsible for the activity. Two cannabinoid receptor subtypes, CB1 and CB2, have been identified, but the complex pharmacological properties of exogenous cannabinoids and endocannabinoids are not fully explained by their signaling. The orphan receptor GPR55 binds a subset of CB1 and CB2 ligands and has been proposed as a cannabinoid receptor. This designation, however, is controversial as a result of recent studies in which lysophosphatidylinositol (LPI) was identified as a GPR55 agonist. Defining a biological role for GPR55 requires GPR55 selective ligands that have been unavailable. From a β-arrestin, high-throughput, high-content screen of 300000 compounds run in collaboration with the Molecular Libraries Probe Production Centers Network initiative (PubChem AID1965), we identified potent GPR55 selective agonists. By modeling of the GPR55 activated state, we compared the GPR55 binding conformations of three of the novel agonists obtained from the screen, CID1792197, CID1172084, and CID2440433 (PubChem Compound IDs), with that of LPI. Our modeling indicates the molecular shapes and electrostatic potential distributions of these agonists mimic those of LPI; the GPR55 binding site accommodates ligands that have inverted-L or T shapes with long, thin profiles that can fit vertically deep in the receptor binding pocket while their broad head regions occupy a horizontal binding pocket near the GPR55 extracellular loops. Our results will allow the optimization and design of second-generation GPR55 ligands and provide a means for distinguishing GPR55 selective ligands from those interacting with cannabinoid receptors.
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Affiliation(s)
| | - Karla E. Madrigal
- Center for Drug Discovery, UNCG Greensboro, Greensboro, NC 27402 USA
| | - Dow P. Hurst
- Center for Drug Discovery, UNCG Greensboro, Greensboro, NC 27402 USA
| | - Haleli Sharir
- Department of Anatomy and Cell Biology and Center for Substance Abuse Research, Temple University, Philadelphia, PA 19140 USA
| | - Diane L. Lynch
- Center for Drug Discovery, UNCG Greensboro, Greensboro, NC 27402 USA
| | - Susanne Heynen-Genel
- Conrad Prebys Center for Chemical Genomics at Sanford-Burnham Medical Research Institute, La Jolla, CA 92037 USA
| | - Loribelle B. Milan
- Conrad Prebys Center for Chemical Genomics at Sanford-Burnham Medical Research Institute, La Jolla, CA 92037 USA
| | - Thomas D.Y. Chung
- Conrad Prebys Center for Chemical Genomics at Sanford-Burnham Medical Research Institute, La Jolla, CA 92037 USA
| | - Herbert H. Seltzman
- Center for Organic and Medicinal Chemistry, Research Triangle Institute, Research Triangle Park, NC 27709 USA
| | - Yushi Bai
- Department of Cell Biology, Duke University, Durham, NC 27708 USA
| | - Marc G. Caron
- Department of Cell Biology, Duke University, Durham, NC 27708 USA
| | - Larry Barak
- Department of Cell Biology, Duke University, Durham, NC 27708 USA
| | - Mary E. Abood
- Department of Anatomy and Cell Biology and Center for Substance Abuse Research, Temple University, Philadelphia, PA 19140 USA
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16
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Shim JY, Rudd J, Ding TT. Distinct second extracellular loop structures of the brain cannabinoid CB(1) receptor: implication in ligand binding and receptor function. Proteins 2011; 79:581-97. [PMID: 21120862 DOI: 10.1002/prot.22907] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The G-protein-coupled receptor (GPCR) second extracellular loop (E2) is known to play an important role in receptor structure and function. The brain cannabinoid (CB(1)) receptor is unique in that it lacks the interloop E2 disulfide linkage to the transmembrane (TM) helical bundle, a characteristic of many GPCRs. Recent mutation studies of the CB(1) receptor, however, suggest the presence of an alternative intraloop disulfide bond between two E2 Cys residues. Considering the oxidation state of these Cys residues, we determine the molecular structures of the 17-residue E2 in the dithiol form (E2(dithiol)) and in the disulfide form (E2(disulfide)) of the CB(1) receptor in a fully hydrated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine bilayer, using a combination of simulated annealing and molecular dynamics simulation approaches. We characterize the CB(1) receptor models with these two E2 forms, CB(1)(E2(dithiol)) and CB(1)(E2(disulfide)), by analyzing interaction energy, contact number, core crevice, and cross correlation. The results show that the distinct E2 structures interact differently with the TM helical bundle and uniquely modify the TM helical topology, suggesting that E2 of the CB(1) receptor plays a critical role in stabilizing receptor structure, regulating ligand binding, and ultimately modulating receptor activation. Further studies on the role of E2 of the CB(1) receptor are warranted, particularly comparisons of the ligand-bound form with the present ligand-free form.
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Affiliation(s)
- Joong-Youn Shim
- JL Chambers Biomedical/Biotechnology Research Institute, North Carolina Central University, Durham, North Carolina 27707, USA.
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17
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Shim JY. Understanding functional residues of the cannabinoid CB1. Curr Top Med Chem 2011; 10:779-98. [PMID: 20370713 DOI: 10.2174/156802610791164210] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Accepted: 10/27/2009] [Indexed: 02/07/2023]
Abstract
The brain cannabinoid (CB(1)) receptor that mediates numerous physiological processes in response to marijuana and other psychoactive compounds is a G protein coupled receptor (GPCR) and shares common structural features with many rhodopsin class GPCRs. For the rational development of therapeutic agents targeting the CB(1) receptor, understanding of the ligand-specific CB(1) receptor interactions responsible for unique G protein signals is crucial. For a more than a decade, a combination of mutagenesis and computational modeling approaches has been successfully employed to study the ligand-specific CB(1) receptor interactions. In this review, after a brief discussion about recent advances in understanding of some structural and functional features of GPCRs commonly applicable to the CB(1) receptor, the CB(1) receptor functional residues reported from mutational studies are divided into three different types, ligand binding (B), receptor stabilization (S) and receptor activation (A) residues, to delineate the nature of the binding pockets of anandamide, CP55940, WIN55212-2 and SR141716A and to describe the molecular events of the ligand-specific CB(1) receptor activation from ligand binding to G protein signaling. Taken these CB(1) receptor functional residues, some of which are unique to the CB(1) receptor, together with the biophysical knowledge accumulated for the GPCR active state, it is possible to propose the early stages of the CB(1) receptor activation process that not only provide some insights into understanding molecular mechanisms of receptor activation but also are applicable for identifying new therapeutic agents by applying the validated structure-based approaches, such as virtual high throughput screening (HTS) and fragment-based approach (FBA).
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Affiliation(s)
- Joong-Youn Shim
- J.L. Chambers Biomedical/Biotechnology Research Institute, North Carolina Central University, 700 George Street, Durham, NC 27707, USA.
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18
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Zhang Y, Xie Z, Wang L, Schreiter B, Lazo JS, Gertsch J, Xie XQ. Mutagenesis and computer modeling studies of a GPCR conserved residue W5.43(194) in ligand recognition and signal transduction for CB2 receptor. Int Immunopharmacol 2011; 11:1303-10. [PMID: 21539938 DOI: 10.1016/j.intimp.2011.04.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 04/15/2011] [Accepted: 04/18/2011] [Indexed: 10/18/2022]
Abstract
W5.43(194), a conserved tryptophan residue among G-protein coupled receptors (GPCRs) and cannabinoid receptors (CB), was examined in the present report for its significance in CB2 receptor ligand binding and adenylyl cyclase (AC) activity. Computer modeling postulates that this site in CB2 may be involved in the affinity of WIN55212-2 and SR144528 through aromatic contacts. In the present study, we reported that a CB2 receptor mutant, W5.43(194)Y, which had a tyrosine (Y) substitution for tryptophan (W), retained the binding affinity for CB agonist CP55940, but reduced binding affinity for CB2 agonist WIN55212-2 and inverse agonist SR144528 by 8-fold and 5-fold, respectively; the CB2 W5.43(194)F and W5.43(194)A mutations significantly affect the binding activities of CP55940, WIN55212-2 and SR144528. Furthermore, we found that agonist-mediated inhibition of the forskolin-induced cAMP production was dramatically diminished in the CB2 mutant W5.43(194)Y, whereas W5.43(194)F and W5.43(194)A mutants resulted in complete elimination of downstream signaling, suggesting that W5.43(194) was essential for the full activation of CB2. These results indicate that both aromatic interaction and hydrogen bonding are involved in ligand binding for the residue W5.43(194), and the mutations of this tryptophan site may affect the conformation of the ligand binding pocket and therefore control the active conformation of the wild type CB2 receptor. W5.43(194)Y/F/A mutations also displayed noticeable enhancement of the constitutive activation probably attributed to the receptor conformational changes resulted from the mutations.
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Affiliation(s)
- Yuxun Zhang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
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19
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Hurst DP, Grossfield A, Lynch DL, Feller S, Romo TD, Gawrisch K, Pitman MC, Reggio PH. A lipid pathway for ligand binding is necessary for a cannabinoid G protein-coupled receptor. J Biol Chem 2010; 285:17954-64. [PMID: 20220143 PMCID: PMC2878557 DOI: 10.1074/jbc.m109.041590] [Citation(s) in RCA: 176] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Revised: 02/13/2010] [Indexed: 11/06/2022] Open
Abstract
Recent isothiocyanate covalent labeling studies have suggested that a classical cannabinoid, (-)-7'-isothiocyanato-11-hydroxy-1',1'dimethylheptyl-hexahydrocannabinol (AM841), enters the cannabinoid CB2 receptor via the lipid bilayer (Pei, Y., Mercier, R. W., Anday, J. K., Thakur, G. A., Zvonok, A. M., Hurst, D., Reggio, P. H., Janero, D. R., and Makriyannis, A. (2008) Chem. Biol. 15, 1207-1219). However, the sequence of steps involved in such a lipid pathway entry has not yet been elucidated. Here, we test the hypothesis that the endogenous cannabinoid sn-2-arachidonoylglycerol (2-AG) attains access to the CB2 receptor via the lipid bilayer. To this end, we have employed microsecond time scale all-atom molecular dynamics (MD) simulations of the interaction of 2-AG with CB2 via a palmitoyl-oleoyl-phosphatidylcholine lipid bilayer. Results suggest the following: 1) 2-AG first partitions out of bulk lipid at the transmembrane alpha-helix (TMH) 6/7 interface; 2) 2-AG then enters the CB2 receptor binding pocket by passing between TMH6 and TMH7; 3) the entrance of the 2-AG headgroup into the CB2 binding pocket is sufficient to trigger breaking of the intracellular TMH3/6 ionic lock and the movement of the TMH6 intracellular end away from TMH3; and 4) subsequent to protonation at D3.49/D6.30, further 2-AG entry into the ligand binding pocket results in both a W6.48 toggle switch change and a large influx of water. To our knowledge, this is the first demonstration via unbiased molecular dynamics that a ligand can access the binding pocket of a class A G protein-coupled receptor via the lipid bilayer and the first demonstration via molecular dynamics of G protein-coupled receptor activation triggered by a ligand binding event.
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Affiliation(s)
- Dow P. Hurst
- From the Department of Chemistry and Biochemistry, Center for Drug Discovery, University of North Carolina, Greensboro, North Carolina 27402
| | - Alan Grossfield
- the Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, New York 14642
| | - Diane L. Lynch
- From the Department of Chemistry and Biochemistry, Center for Drug Discovery, University of North Carolina, Greensboro, North Carolina 27402
| | - Scott Feller
- the Department of Chemistry, Wabash College, Crawfordsville, Indiana 47933
| | - Tod D. Romo
- the Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, New York 14642
| | - Klaus Gawrisch
- Membrane Biochemistry/Biophysics, NIAAA, National Institutes of Health, Bethesda, Maryland 20892, and
| | - Michael C. Pitman
- the Computational Biology Center, IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598
| | - Patricia H. Reggio
- From the Department of Chemistry and Biochemistry, Center for Drug Discovery, University of North Carolina, Greensboro, North Carolina 27402
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20
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Westrich L, Gil-Mast S, Kortagere S, Kuzhikandathil EV. Development of tolerance in D3 dopamine receptor signaling is accompanied by distinct changes in receptor conformation. Biochem Pharmacol 2009; 79:897-907. [PMID: 19879251 DOI: 10.1016/j.bcp.2009.10.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2009] [Revised: 10/16/2009] [Accepted: 10/19/2009] [Indexed: 10/20/2022]
Abstract
The D3 but not D2 dopamine receptors exhibit a tolerance property in which agonist-induced D3 receptor response progressively decreases upon repeated agonist stimulation. We have previously shown that the D3 receptor tolerance property is not mediated by receptor internalization, persistent agonist binding or a decrease in receptor binding affinity. In this paper, we test the hypothesis that alterations in D3 receptor conformation underlie the tolerance property. Structural models of wild type and mutant human D3 receptors were generated using the beta adrenergic receptor crystal structure as a template. These models suggested that the agonist-bound D3 receptor undergoes conformational changes that could underlie its tolerance property. To experimentally assess changes in receptor conformation, we measured the accessibility of native cysteine residues present in the extracellular and transmembrane regions of the human D3 receptor to two different thiol-modifying biotinylating reagents. The accessibilities of the native cysteine residues present in the D3 receptor were assessed under control conditions, in the presence of agonist and under conditions that induced receptor tolerance. By comparing the accessibility of D3 receptor cysteine residues to hydrophobic and hydrophilic thiol-modifying biotinylating reagents, we show that the alteration of D3 receptor conformation during tolerance involves the net movement of cysteine residues into a hydrophobic environment. Our results show that the conformation state of the D3 receptor during tolerance is distinct from the conformation under basal and agonist-bound conditions. The results suggest that the D3 receptor tolerance property is mediated by conformational changes that may uncouple the receptor from G-protein signaling.
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Affiliation(s)
- Ligia Westrich
- Department of Pharmacology & Physiology and Integrative Neuroscience Graduate Program, UMDNJ-New Jersey Medical School, Newark, NJ 07103, USA
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21
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Tiburu EK, Tyukhtenko S, Deshmukh L, Vinogradova O, Janero DR, Makriyannis A. Structural biology of human cannabinoid receptor-2 helix 6 in membrane-mimetic environments. Biochem Biophys Res Commun 2009; 384:243-8. [PMID: 19397896 DOI: 10.1016/j.bbrc.2009.04.099] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Accepted: 04/19/2009] [Indexed: 10/20/2022]
Abstract
We detail the structure and dynamics of a synthetic peptide corresponding to transmembrane helix 6 (TMH6) of human cannabinoid receptor-2 (hCB2) in biomembrane-mimetic environments. The peptide's NMR structural biology is characterized by two alpha-helical domains bridged by a flexible, nonhelical hinge region containing a highly-conserved CWFP motif with an environmentally sensitive, Pro-based conformational switch. Buried within the peptide's flexible region, W(258) may hydrogen-bond with L(255) to help stabilize the Pro-kinked hCB2 TMH6 structure and position C(257) advantageously for interaction with agonist ligands. These characteristics of hCB2 TMH6 are potential structural features of ligand-induced hCB2 activation in vivo.
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Affiliation(s)
- Elvis K Tiburu
- Center for Drug Discovery and Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115-5000, USA
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