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Gao ZG, Auchampach JA, Jacobson KA. Species dependence of A 3 adenosine receptor pharmacology and function. Purinergic Signal 2023; 19:523-550. [PMID: 36538251 PMCID: PMC9763816 DOI: 10.1007/s11302-022-09910-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 11/26/2022] [Indexed: 12/24/2022] Open
Abstract
Efforts to fully understand pharmacological differences between G protein-coupled receptor (GPCR) species homologues are generally not pursued in detail during the drug development process. To date, many GPCRs that have been successfully targeted are relatively well-conserved across species in amino acid sequence and display minimal variability of biological effects. However, the A3 adenosine receptor (AR), an exciting drug target for a multitude of diseases associated with tissue injury, ischemia, and inflammation, displays as little as 70% sequence identity among mammalian species (e.g., rodent vs. primate) commonly used in drug development. Consequently, the pharmacological properties of synthetic A3AR ligands vary widely, not only in binding affinity, selectivity, and signaling efficacy, but to the extent that some function as agonists in some species and antagonists in others. Numerous heterocyclic antagonists that have nM affinity at the human A3AR are inactive or weakly active at the rat and mouse A3ARs. Positive allosteric modulators, including the imidazo [4,5-c]quinolin-4-amine derivative LUF6000, are only active at human and some larger animal species that have been evaluated (rabbit and dog), but not rodents. A3AR agonists evoke systemic degranulation of rodent, but not human mast cells. The rat A3AR undergoes desensitization faster than the human A3AR, but the human homologue can be completely re-sensitized and recycled back to the cell surface. Thus, comprehensive pharmacological evaluation and awareness of potential A3AR species differences are critical in studies to further understand the basic biological functions of this unique AR subtype. Recombinant A3ARs from eight different species have been pharmacologically characterized thus far. In this review, we describe in detail current knowledge of species differences in genetic identity, G protein-coupling, receptor regulation, and both orthosteric and allosteric A3AR pharmacology.
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Affiliation(s)
- Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892-0810, USA.
| | - John A Auchampach
- Department of Pharmacology and Toxicology, and the Cardiovascular Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892-0810, USA.
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2
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Allosteric binding cooperativity in a kinetic context. Drug Discov Today 2023; 28:103441. [PMID: 36372329 DOI: 10.1016/j.drudis.2022.103441] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 11/02/2022] [Accepted: 11/08/2022] [Indexed: 11/13/2022]
Abstract
Allosteric modulators are of prime interest in drug discovery. These drugs regulate the binding and function of endogenous ligands, with some advantages over orthosteric ligands. A typical pharmacological parameter in allosteric modulation is binding cooperativity. This property can yield unexpected but illuminating results when decomposed into its kinetic parameters. Using two reference models (the allosteric ternary complex receptor model and a heterodimer receptor model), a relationship has been derived for the cooperativity rate constant parameters. This relationship allows many combinations of the cooperativity kinetic parameters for a single binding cooperativity value obtained under equilibrium conditions. This assessment may help understand striking experimental results involving allosteric modulation and suggest further investigations in the field.
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3
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Fallot LB, Suresh RR, Fisher CL, Salmaso V, O'Connor RD, Kaufman N, Gao ZG, Auchampach JA, Jacobson KA. Structure-Activity Studies of 1 H-Imidazo[4,5- c]quinolin-4-amine Derivatives as A 3 Adenosine Receptor Positive Allosteric Modulators. J Med Chem 2022; 65:15238-15262. [PMID: 36367749 PMCID: PMC10354740 DOI: 10.1021/acs.jmedchem.2c01170] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We previously reported 1H-imidazo[4,5-c]quinolin-4-amines as A3 adenosine receptor (A3AR) positive allosteric modulators (PAMs). A3AR agonists, but not PAMs, are in clinical trials for inflammatory diseases and liver conditions. We synthesized new analogues to distinguish 2-cyclopropyl antagonist 17 (orthosteric interaction demonstrated by binding and predicted computationally) from PAMs (derivatives with large 2-alkyl/cycloalkyl/bicycloalkyl groups). We predicted PAM binding at a hydrophobic site on the A3AR cytosolic interface. Although having low Caco-2 permeability and high plasma protein binding, hydrophobic 2-cyclohept-4-enyl-N-3,4-dichlorophenyl, MRS7788 18, and 2-heptan-4-yl-N-4-iodophenyl, MRS8054 39, derivatives were orally bioavailable in rat. 2-Heptan-4-yl-N-3,4-dichlorophenyl 14 and 2-cyclononyl-N-3,4-dichlorophenyl 20 derivatives and 39 greatly enhanced Cl-IB-MECA-stimulated [35S]GTPγS binding Emax, with only 12b trending toward decreasing the agonist EC50. A feasible route for radio-iodination at the p-position of a 4-phenylamino substituent suggests a potential radioligand for allosteric site binding. Herein, we advanced an allosteric approach to developing A3AR-activating drugs that are potentially event- and site-specific in action.
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Affiliation(s)
- Lucas B Fallot
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, Maryland 20814, United States
- Department of Chemistry and Life Science, United States Military Academy, 646 Swift Road, West Point, New York 10996, United States
| | - R Rama Suresh
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | | | - Veronica Salmaso
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Robert D O'Connor
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Noy Kaufman
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | | | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
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Pasquini S, Contri C, Cappello M, Borea PA, Varani K, Vincenzi F. Update on the recent development of allosteric modulators for adenosine receptors and their therapeutic applications. Front Pharmacol 2022; 13:1030895. [PMID: 36278183 PMCID: PMC9581118 DOI: 10.3389/fphar.2022.1030895] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
Adenosine receptors (ARs) have been identified as promising therapeutic targets for countless pathological conditions, spanning from inflammatory diseases to central nervous system disorders, from cancer to metabolic diseases, from cardiovascular pathologies to respiratory diseases, and beyond. This extraordinary therapeutic potential is mainly due to the plurality of pathophysiological actions of adenosine and the ubiquitous expression of its receptors. This is, however, a double-edged sword that makes the clinical development of effective ligands with tolerable side effects difficult. Evidence of this is the low number of AR agonists or antagonists that have reached the market. An alternative approach is to target allosteric sites via allosteric modulators, compounds endowed with several advantages over orthosteric ligands. In addition to the typical advantages of allosteric modulators, those acting on ARs could benefit from the fact that adenosine levels are elevated in pathological tissues, thus potentially having negligible effects on normal tissues where adenosine levels are maintained low. Several A1 and various A3AR allosteric modulators have been identified so far, and some of them have been validated in different preclinical settings, achieving promising results. Less fruitful, instead, has been the discovery of A2A and A2BAR allosteric modulators, although the results obtained up to now are encouraging. Collectively, data in the literature suggests that allosteric modulators of ARs could represent valuable pharmacological tools, potentially able to overcome the limitations of orthosteric ligands.
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Affiliation(s)
- Silvia Pasquini
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Ferrara, Italy
| | - Chiara Contri
- Department of Translational Medicine, University of Ferrara, Ferrara, Italy
| | - Martina Cappello
- Department of Translational Medicine, University of Ferrara, Ferrara, Italy
| | | | - Katia Varani
- Department of Translational Medicine, University of Ferrara, Ferrara, Italy
- *Correspondence: Katia Varani,
| | - Fabrizio Vincenzi
- Department of Translational Medicine, University of Ferrara, Ferrara, Italy
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5
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IJzerman AP, Jacobson KA, Müller CE, Cronstein BN, Cunha RA. International Union of Basic and Clinical Pharmacology. CXII: Adenosine Receptors: A Further Update. Pharmacol Rev 2022; 74:340-372. [PMID: 35302044 PMCID: PMC8973513 DOI: 10.1124/pharmrev.121.000445] [Citation(s) in RCA: 70] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Our previous International Union of Basic and Clinical Pharmacology report on the nomenclature and classification of adenosine receptors (2011) contained a number of emerging developments with respect to this G protein-coupled receptor subfamily, including protein structure, protein oligomerization, protein diversity, and allosteric modulation by small molecules. Since then, a wealth of new data and results has been added, allowing us to explore novel concepts such as target binding kinetics and biased signaling of adenosine receptors, to examine a multitude of receptor structures and novel ligands, to gauge new pharmacology, and to evaluate clinical trials with adenosine receptor ligands. This review should therefore be considered a further update of our previous reports from 2001 and 2011. SIGNIFICANCE STATEMENT: Adenosine receptors (ARs) are of continuing interest for future treatment of chronic and acute disease conditions, including inflammatory diseases, neurodegenerative afflictions, and cancer. The design of AR agonists ("biased" or not) and antagonists is largely structure based now, thanks to the tremendous progress in AR structural biology. The A2A- and A2BAR appear to modulate the immune response in tumor biology. Many clinical trials for this indication are ongoing, whereas an A2AAR antagonist (istradefylline) has been approved as an anti-Parkinson agent.
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Affiliation(s)
- Adriaan P IJzerman
- Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (A.P.IJ.); National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Molecular Recognition Section, Bethesda, Maryland (K.A.J.); Universität Bonn, Bonn, Germany (C.E.M.); New York University School of Medicine, New York, New York (B.N.C.); and Center for Neurosciences and Cell Biology and Faculty of Medicine, University of Coimbra, Coimbra, Portugal (R.A.C.)
| | - Kenneth A Jacobson
- Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (A.P.IJ.); National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Molecular Recognition Section, Bethesda, Maryland (K.A.J.); Universität Bonn, Bonn, Germany (C.E.M.); New York University School of Medicine, New York, New York (B.N.C.); and Center for Neurosciences and Cell Biology and Faculty of Medicine, University of Coimbra, Coimbra, Portugal (R.A.C.)
| | - Christa E Müller
- Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (A.P.IJ.); National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Molecular Recognition Section, Bethesda, Maryland (K.A.J.); Universität Bonn, Bonn, Germany (C.E.M.); New York University School of Medicine, New York, New York (B.N.C.); and Center for Neurosciences and Cell Biology and Faculty of Medicine, University of Coimbra, Coimbra, Portugal (R.A.C.)
| | - Bruce N Cronstein
- Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (A.P.IJ.); National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Molecular Recognition Section, Bethesda, Maryland (K.A.J.); Universität Bonn, Bonn, Germany (C.E.M.); New York University School of Medicine, New York, New York (B.N.C.); and Center for Neurosciences and Cell Biology and Faculty of Medicine, University of Coimbra, Coimbra, Portugal (R.A.C.)
| | - Rodrigo A Cunha
- Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (A.P.IJ.); National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Molecular Recognition Section, Bethesda, Maryland (K.A.J.); Universität Bonn, Bonn, Germany (C.E.M.); New York University School of Medicine, New York, New York (B.N.C.); and Center for Neurosciences and Cell Biology and Faculty of Medicine, University of Coimbra, Coimbra, Portugal (R.A.C.)
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6
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Korkutata M, Agrawal L, Lazarus M. Allosteric Modulation of Adenosine A 2A Receptors as a New Therapeutic Avenue. Int J Mol Sci 2022; 23:ijms23042101. [PMID: 35216213 PMCID: PMC8880556 DOI: 10.3390/ijms23042101] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/11/2022] [Accepted: 02/11/2022] [Indexed: 12/26/2022] Open
Abstract
The therapeutic potential of targeting adenosine A2A receptors (A2ARs) is immense due to their broad expression in the body and central nervous system. The role of A2ARs in cardiovascular function, inflammation, sleep/wake behaviors, cognition, and other primary nervous system functions has been extensively studied. Numerous A2AR agonist and antagonist molecules are reported, many of which are currently in clinical trials or have already been approved for treatment. Allosteric modulators can selectively elicit a physiologic response only where and when the orthosteric ligand is released, which reduces the risk of an adverse effect resulting from A2AR activation. Thus, these allosteric modulators have a potential therapeutic advantage over classical agonist and antagonist molecules. This review focuses on the recent developments regarding allosteric A2AR modulation, which is a promising area for future pharmaceutical research because the list of existing allosteric A2AR modulators and their physiologic effects is still short.
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Affiliation(s)
- Mustafa Korkutata
- Department of Neurology, Division of Sleep Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA;
| | - Lokesh Agrawal
- Molecular Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Onna 904-0412, Japan;
| | - Michael Lazarus
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba 305-8575, Japan
- Correspondence: ; Tel.: +81-29-853-3681
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7
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Mailavaram RP, Al-Attraqchi OH, Kar S, Ghosh S. Current Status in the Design and Development of Agonists and Antagonists of Adenosine A3 Receptor as Potential Therapeutic Agents. Curr Pharm Des 2019; 25:2772-2787. [DOI: 10.2174/1381612825666190716114056] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 07/03/2019] [Indexed: 12/31/2022]
Abstract
Adenosine receptors (ARs) belongs to the family of G-protein coupled receptors (GPCR) that are responsible
for the modulation of a wide variety of physiological functions. The ARs are also implicated in many
diseases such as cancer, arthritis, cardiovascular and renal diseases. The adenosine A3 receptor (A3AR) has
emerged as a potential drug target for the progress of new and effective therapeutic agents for the treatment of
various pathological conditions. This receptor’s involvement in many diseases and its validity as a target has been
established by many studies. Both agonists and antagonists of A3AR have been extensively investigated in the last
decade with the goal of developing novel drugs for treating diseases related to immune disorders, inflammation,
cancer, and others. In this review, we shall focus on the medicinal chemistry of A3AR ligands, exploring the
diverse chemical classes that have been projected as future leading drug candidates. Also, the recent advances in
the therapeuetic applications of A3AR ligands are highlighted.
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Affiliation(s)
- Raghu P. Mailavaram
- Department of Pharmaceutical Chemistry, Shri Vishnu College of Pharmacy, Vishnupur (Affiliated to Andhra University), Bhimavaram, W.G. Dist., AP, India
| | - Omar H.A. Al-Attraqchi
- Faculty of Pharmacy, Philadelphia University-Jordan, P.O BOX (1), Philadelphia University- 19392, Amman, Jordan
| | - Supratik Kar
- Interdisciplinary Center for Nanotoxicity, Department of Chemistry, Physics and Atmospheric Sciences, Jackson State University, Jackson, MS 39217, United States
| | - Shinjita Ghosh
- School of Public Health, Jackson State University, Jackson, MS 39217, United States
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8
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Al-Shar'i NA, Al-Balas QA. Molecular Dynamics Simulations of Adenosine Receptors: Advances, Applications and Trends. Curr Pharm Des 2019; 25:783-816. [DOI: 10.2174/1381612825666190304123414] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 02/26/2019] [Indexed: 01/09/2023]
Abstract
:
Adenosine receptors (ARs) are transmembrane proteins that belong to the G protein-coupled receptors
(GPCRs) superfamily and mediate the biological functions of adenosine. To date, four AR subtypes are known,
namely A1, A2A, A2B and A3 that exhibit different signaling pathways, tissue localization, and mechanisms of
activation. Moreover, the widespread ARs and their implication in numerous physiological and pathophysiological
conditions had made them pivotal therapeutic targets for developing clinically effective agents.
:
The crystallographic success in identifying the 3D crystal structures of A2A and A1 ARs has dramatically enriched
our understanding of their structural and functional properties such as ligand binding and signal transduction.
This, in turn, has provided a structural basis for a larger contribution of computational methods, particularly molecular
dynamics (MD) simulations, toward further investigation of their molecular properties and designing
bioactive ligands with therapeutic potential. MD simulation has been proved to be an invaluable tool in investigating
ARs and providing answers to some critical questions. For example, MD has been applied in studying ARs
in terms of ligand-receptor interactions, molecular recognition, allosteric modulations, dimerization, and mechanisms
of activation, collectively aiding in the design of subtype selective ligands.
:
In this review, we focused on the advances and different applications of MD simulations utilized to study the
structural and functional aspects of ARs that can foster the structure-based design of drug candidates. In addition,
relevant literature was briefly discussed which establishes a starting point for future advances in the field of drug
discovery to this pivotal group of drug targets.
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Affiliation(s)
- Nizar A. Al-Shar'i
- Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmacy, Jordan University of Science and Technology, P.O. Box 3030, Irbid 22110, Jordan
| | - Qosay A. Al-Balas
- Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmacy, Jordan University of Science and Technology, P.O. Box 3030, Irbid 22110, Jordan
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9
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Mahmod Al-Qattan MN, Mordi MN. Molecular Basis of Modulating Adenosine Receptors Activities. Curr Pharm Des 2019; 25:817-831. [DOI: 10.2174/1381612825666190304122624] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 02/26/2019] [Indexed: 01/04/2023]
Abstract
Modulating cellular processes through extracellular chemical stimuli is medicinally an attractive approach to control disease conditions. GPCRs are the most important group of transmembranal receptors that produce different patterns of activations using intracellular mediators (such as G-proteins and Beta-arrestins). Adenosine receptors (ARs) belong to GPCR class and are divided into A1AR, A2AAR, A2BAR and A3AR. ARs control different physiological activities thus considered valuable target to control neural, heart, inflammatory and other metabolic disorders. Targeting ARs using small molecules essentially works by binding orthosteric and/or allosteric sites of the receptors. Although targeting orthosteric site is considered typical to modulate receptor activity, allosteric sites provide better subtype selectivity, saturable modulation of activity and variable activation patterns. Each receptor exists in dynamical equilibrium between conformational ensembles. The equilibrium is affected by receptor interaction with other molecules. Changing the population of conformational ensembles of the receptor is the method by which orthosteric, allosteric and other cellular components control receptor signaling. Herein, the interactions of ARs with orthosteric, allosteric ligands as well as intracellular mediators are described. A quinary interaction model for the receptor is proposed and energy wells for major conformational ensembles are retrieved.
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Affiliation(s)
| | - Mohd Nizam Mordi
- Centre For Drug Research, Universiti Sains Malaysia, 11800 Gelugor, Penang, Malaysia
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Sykes DA, Stoddart LA, Kilpatrick LE, Hill SJ. Binding kinetics of ligands acting at GPCRs. Mol Cell Endocrinol 2019; 485:9-19. [PMID: 30738950 PMCID: PMC6406023 DOI: 10.1016/j.mce.2019.01.018] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 01/19/2019] [Accepted: 01/19/2019] [Indexed: 12/31/2022]
Abstract
The influence of drug-receptor binding kinetics has often been overlooked during the development of new therapeutics that target G protein-coupled receptors (GPCRs). Over the last decade there has been a growing understanding that an in-depth knowledge of binding kinetics at GPCRs is required to successfully target this class of proteins. Ligand binding to a GPCR is often not a simple single step process with ligand freely diffusing in solution. This review will discuss the experiments and equations that are commonly used to measure binding kinetics and how factors such as allosteric regulation, rebinding and ligand interaction with the plasma membrane may influence these measurements. We will then consider the molecular characteristics of a ligand and if these can be linked to association and dissociation rates.
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Affiliation(s)
- David A Sykes
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Leigh A Stoddart
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Laura E Kilpatrick
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Stephen J Hill
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.
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11
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Jacobson KA, Merighi S, Varani K, Borea PA, Baraldi S, Tabrizi MA, Romagnoli R, Baraldi PG, Ciancetta A, Tosh DK, Gao ZG, Gessi S. A 3 Adenosine Receptors as Modulators of Inflammation: From Medicinal Chemistry to Therapy. Med Res Rev 2018; 38:1031-1072. [PMID: 28682469 PMCID: PMC5756520 DOI: 10.1002/med.21456] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 05/02/2017] [Accepted: 06/13/2017] [Indexed: 01/09/2023]
Abstract
The A3 adenosine receptor (A3 AR) subtype is a novel, promising therapeutic target for inflammatory diseases, such as rheumatoid arthritis (RA) and psoriasis, as well as liver cancer. A3 AR is coupled to inhibition of adenylyl cyclase and regulation of mitogen-activated protein kinase (MAPK) pathways, leading to modulation of transcription. Furthermore, A3 AR affects functions of almost all immune cells and the proliferation of cancer cells. Numerous A3 AR agonists, partial agonists, antagonists, and allosteric modulators have been reported, and their structure-activity relationships (SARs) have been studied culminating in the development of potent and selective molecules with drug-like characteristics. The efficacy of nucleoside agonists may be suppressed to produce antagonists, by structural modification of the ribose moiety. Diverse classes of heterocycles have been discovered as selective A3 AR blockers, although with large species differences. Thus, as a result of intense basic research efforts, the outlook for development of A3 AR modulators for human therapeutics is encouraging. Two prototypical selective agonists, N6-(3-Iodobenzyl)adenosine-5'-N-methyluronamide (IB-MECA; CF101) and 2-chloro-N6-(3-iodobenzyl)-adenosine-5'-N-methyluronamide (Cl-IB-MECA; CF102), have progressed to advanced clinical trials. They were found safe and well tolerated in all preclinical and human clinical studies and showed promising results, particularly in psoriasis and RA, where the A3 AR is both a promising therapeutic target and a biologically predictive marker, suggesting a personalized medicine approach. Targeting the A3 AR may pave the way for safe and efficacious treatments for patient populations affected by inflammatory diseases, cancer, and other conditions.
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Affiliation(s)
- Kenneth A. Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD20892
| | - Stefania Merighi
- Department of Medical Sciences, Pharmacology Section, University of Ferrara, Via Fossato di Mortara 17/19, 44121 Ferrara, Italy
| | - Katia Varani
- Department of Medical Sciences, Pharmacology Section, University of Ferrara, Via Fossato di Mortara 17/19, 44121 Ferrara, Italy
| | - Pier Andrea Borea
- Department of Medical Sciences, Pharmacology Section, University of Ferrara, Via Fossato di Mortara 17/19, 44121 Ferrara, Italy
| | - Stefania Baraldi
- Department of Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
| | - Mojgan Aghazadeh Tabrizi
- Department of Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
| | - Romeo Romagnoli
- Department of Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
| | - Pier Giovanni Baraldi
- Department of Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
| | - Antonella Ciancetta
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD20892
| | - Dilip K. Tosh
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD20892
| | - Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD20892
| | - Stefania Gessi
- Department of Medical Sciences, Pharmacology Section, University of Ferrara, Via Fossato di Mortara 17/19, 44121 Ferrara, Italy
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Singh S, Cooper S, Glenn JR, Beresford J, Percival LR, Tyndall JDA, Hill SJ, Kilpatrick LE, Vernall AJ. Synthesis of novel (benzimidazolyl)isoquinolinols and evaluation as adenosine A1 receptor tools. RSC Adv 2018; 8:16362-16369. [PMID: 35542203 PMCID: PMC9080270 DOI: 10.1039/c7ra13148h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 04/21/2018] [Indexed: 11/21/2022] Open
Abstract
G protein-coupled receptors (GPCRs) constitute the largest family of transmembrane receptors in eukaryotes. The adenosine A1 receptor (A1AR) is a class A GPCR that is of interest as a therapeutic target particularly in the treatment of cardiovascular disease and neuropathic pain. Increased knowledge of the role A1AR plays in mediating these pathophysiological processes will help realise the therapeutic potential of this receptor. There is a lack of enabling tools such as selective fluorescent probes to study A1AR, therefore we designed a series of (benzimidazolyl)isoquinolinols conjugated to a fluorescent dye (31–35, 42–43). An improved procedure for the synthesis of isoquinolinols from tetrahydroisoquinolinols via oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and atmospheric oxygen is reported. This synthetic method offers advantages over previous metal-based methods for the preparation of isoquinolinols and isoquinolines, which are important scaffolds found in many biologically active compounds and natural products. We report the first synthesis of the (benzimidazolyl)isoquinolinol compound class, however the fluorescent conjugates were not successful as A1AR fluorescent ligands. Mild, metal free aromatization of tetrahydroisoquinolinols. Synthesis of (benzimidazolyl)isoquinolinols.![]()
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Affiliation(s)
- Sameek Singh
- School of Pharmacy
- University of Otago
- Dunedin 9054
- New Zealand
| | - Samantha L. Cooper
- Physiology, Pharmacology and Neuroscience Division
- School of Life Sciences
- University of Nottingham
- Nottingham
- UK
| | - Jacqueline R. Glenn
- Physiology, Pharmacology and Neuroscience Division
- School of Life Sciences
- University of Nottingham
- Nottingham
- UK
| | - Jessica Beresford
- Physiology, Pharmacology and Neuroscience Division
- School of Life Sciences
- University of Nottingham
- Nottingham
- UK
| | - Lydia R. Percival
- Physiology, Pharmacology and Neuroscience Division
- School of Life Sciences
- University of Nottingham
- Nottingham
- UK
| | | | - Stephen J. Hill
- Physiology, Pharmacology and Neuroscience Division
- School of Life Sciences
- University of Nottingham
- Nottingham
- UK
| | - Laura E. Kilpatrick
- Physiology, Pharmacology and Neuroscience Division
- School of Life Sciences
- University of Nottingham
- Nottingham
- UK
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13
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Du L, Gao ZG, Paoletta S, Wan TC, Gizewski ET, Barbour S, van Veldhoven JPD, IJzerman AP, Jacobson KA, Auchampach JA. Species differences and mechanism of action of A 3 adenosine receptor allosteric modulators. Purinergic Signal 2017; 14:59-71. [PMID: 29170977 DOI: 10.1007/s11302-017-9592-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 11/01/2017] [Indexed: 02/01/2023] Open
Abstract
Activity of the A3 adenosine receptor (AR) allosteric modulators LUF6000 (2-cyclohexyl-N-(3,4-dichlorophenyl)-1H-imidazo [4,5-c]quinolin-4-amine) and LUF6096 (N-{2-[(3,4-dichlorophenyl)amino]quinolin-4-yl}cyclohexanecarbox-amide) was compared at four A3AR species homologs used in preclinical drug development. In guanosine 5'-[γ-[35S]thio]triphosphate ([35S]GTPγS) binding assays with cell membranes isolated from human embryonic kidney cells stably expressing recombinant A3ARs, both modulators substantially enhanced agonist efficacy at human, dog, and rabbit A3ARs but provided only weak activity at mouse A3ARs. For human, dog, and rabbit, both modulators increased the maximal efficacy of the A3AR agonist 2-chloro-N 6-(3-iodobenzyl)adenosine-5'-N-methylcarboxamide as well as adenosine > 2-fold, while slightly reducing potency in human and dog. Based on results from N 6-(4-amino-3-[125I]iodobenzyl)adenosine-5'-N-methylcarboxamide ([125I]I-AB-MECA) binding assays, we hypothesize that potency reduction is explained by an allosterically induced slowing in orthosteric ligand binding kinetics that reduces the rate of formation of ligand-receptor complexes. Mutation of four amino acid residues of the human A3AR to the murine sequence identified the extracellular loop 1 (EL1) region as being important in selectively controlling the allosteric actions of LUF6096 on [125I]I-AB-MECA binding kinetics. Homology modeling suggested interaction between species-variable EL1 and agonist-contacting EL2. These results indicate that A3AR allostery is species-dependent and provide mechanistic insights into this therapeutically promising class of agents.
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Affiliation(s)
- Lili Du
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 200892-0810, USA
| | - Silvia Paoletta
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 200892-0810, USA
| | - Tina C Wan
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Elizabeth T Gizewski
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Samantha Barbour
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Jacobus P D van Veldhoven
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, PO Box 9502, 2300 RA, Leiden, The Netherlands
| | - Adriaan P IJzerman
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, PO Box 9502, 2300 RA, Leiden, The Netherlands
| | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 200892-0810, USA
| | - John A Auchampach
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
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14
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Sakkal LA, Rajkowski KZ, Armen RS. Prediction of consensus binding mode geometries for related chemical series of positive allosteric modulators of adenosine and muscarinic acetylcholine receptors. J Comput Chem 2017; 38:1209-1228. [PMID: 28130813 PMCID: PMC5403616 DOI: 10.1002/jcc.24728] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Revised: 11/29/2016] [Accepted: 12/20/2016] [Indexed: 12/13/2022]
Abstract
Following insights from recent crystal structures of the muscarinic acetylcholine receptor, binding modes of Positive Allosteric Modulators (PAMs) were predicted under the assumption that PAMs should bind to the extracellular surface of the active state. A series of well-characterized PAMs for adenosine (A1 R, A2A R, A3 R) and muscarinic acetylcholine (M1 R, M5 R) receptors were modeled using both rigid and flexible receptor CHARMM-based molecular docking. Studies of adenosine receptors investigated the molecular basis of the probe-dependence of PAM activity by modeling in complex with specific agonist radioligands. Consensus binding modes map common pharmacophore features of several chemical series to specific binding interactions. These models provide a rationalization of how PAM binding slows agonist radioligand dissociation kinetics. M1 R PAMs were predicted to bind in the analogous M2 R PAM LY2119620 binding site. The M5 R NAM (ML-375) was predicted to bind in the PAM (ML-380) binding site with a unique induced-fit receptor conformation. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Leon A. Sakkal
- Department of Pharmaceutical Sciences, College of Pharmacy, Thomas Jefferson University, 901 Walnut St. Suite 918. Philadelphia, PA 19170
| | - Kyle Z. Rajkowski
- Department of Pharmaceutical Sciences, College of Pharmacy, Thomas Jefferson University, 901 Walnut St. Suite 918. Philadelphia, PA 19170
| | - Roger S. Armen
- Department of Pharmaceutical Sciences, College of Pharmacy, Thomas Jefferson University, 901 Walnut St. Suite 918. Philadelphia, PA 19170
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15
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Yu Z, Liu J, van Veldhoven JPD, IJzerman AP, Schalij MJ, Pijnappels DA, Heitman LH, de Vries AAF. Allosteric Modulation of Kv11.1 (hERG) Channels Protects Against Drug-Induced Ventricular Arrhythmias. Circ Arrhythm Electrophysiol 2016; 9:e003439. [PMID: 27071825 DOI: 10.1161/circep.115.003439] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 02/04/2016] [Indexed: 12/26/2022]
Abstract
BACKGROUND Ventricular arrhythmias as a result of unintentional blockade of the Kv11.1 (hERG [human ether-à-go-go-related gene]) channel are a major safety concern in drug development. In past years, several highly prescribed drugs have been withdrawn for their ability to cause such proarrhythmia. Here, we investigated whether the proarrhythmic risk of existing drugs could be reduced by Kv11.1 allosteric modulators. METHODS AND RESULTS Using [(3)H]dofetilide-binding assays with membranes of human Kv11.1-expressing human embryonic kidney 293 cells, 2 existing compounds (VU0405601 and ML-T531) and a newly synthesized compound (LUF7244) were found to be negative allosteric modulators of dofetilide binding to the Kv11.1 channel, with LUF7244 showing the strongest effect at 10 μmol/L. The Kv11.1 affinities of typical blockers (ie, dofetilide, astemizole, sertindole, and cisapride) were significantly decreased by LUF7244. Treatment of confluent neonatal rat ventricular myocyte (NRVM) monolayers with astemizole or sertindole caused heterogeneous prolongation of action potential duration and a high incidence of early afterdepolarizations on 1-Hz electric point stimulation, occasionally leading to unstable, self-terminating tachyarrhythmias. Pretreatment of NRVMs with LUF7244 prevented these proarrhythmic effects. NRVM monolayers treated with LUF7244 alone displayed electrophysiological properties indistinguishable from those of untreated NRVM cultures. Prolonged exposure of NRVMs to LUF7244 or LUF7244 plus astemizole did not affect their viability, excitability, and contractility as assessed by molecular, immunological, and electrophysiological assays. CONCLUSIONS Allosteric modulation of the Kv11.1 channel efficiently suppresses drug-induced ventricular arrhythmias in vitro by preventing potentially arrhythmogenic changes in action potential characteristics, raising the possibility to resume the clinical use of unintended Kv11.1 blockers via pharmacological combination therapy.
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Affiliation(s)
- Zhiyi Yu
- From the Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (Z.Y., J.P.D.v.V., A.P.I., L.H.H.); Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands (J.L., M.J.S., D.A.P., A.A.F.d.V.); and ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.L., A.A.F.d.V.)
| | - Jia Liu
- From the Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (Z.Y., J.P.D.v.V., A.P.I., L.H.H.); Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands (J.L., M.J.S., D.A.P., A.A.F.d.V.); and ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.L., A.A.F.d.V.)
| | - Jacobus P D van Veldhoven
- From the Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (Z.Y., J.P.D.v.V., A.P.I., L.H.H.); Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands (J.L., M.J.S., D.A.P., A.A.F.d.V.); and ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.L., A.A.F.d.V.)
| | - Adriaan P IJzerman
- From the Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (Z.Y., J.P.D.v.V., A.P.I., L.H.H.); Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands (J.L., M.J.S., D.A.P., A.A.F.d.V.); and ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.L., A.A.F.d.V.)
| | - Martin J Schalij
- From the Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (Z.Y., J.P.D.v.V., A.P.I., L.H.H.); Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands (J.L., M.J.S., D.A.P., A.A.F.d.V.); and ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.L., A.A.F.d.V.)
| | - Daniël A Pijnappels
- From the Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (Z.Y., J.P.D.v.V., A.P.I., L.H.H.); Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands (J.L., M.J.S., D.A.P., A.A.F.d.V.); and ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.L., A.A.F.d.V.)
| | - Laura H Heitman
- From the Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (Z.Y., J.P.D.v.V., A.P.I., L.H.H.); Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands (J.L., M.J.S., D.A.P., A.A.F.d.V.); and ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.L., A.A.F.d.V.).
| | - Antoine A F de Vries
- From the Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (Z.Y., J.P.D.v.V., A.P.I., L.H.H.); Laboratory of Experimental Cardiology, Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands (J.L., M.J.S., D.A.P., A.A.F.d.V.); and ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.L., A.A.F.d.V.).
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16
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Guo D, Heitman LH, IJzerman AP. Kinetic Aspects of the Interaction between Ligand and G Protein-Coupled Receptor: The Case of the Adenosine Receptors. Chem Rev 2016; 117:38-66. [DOI: 10.1021/acs.chemrev.6b00025] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Dong Guo
- Division of Medicinal Chemistry,
Leiden Academic Centre for Drug Research (LACDR), Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Laura H. Heitman
- Division of Medicinal Chemistry,
Leiden Academic Centre for Drug Research (LACDR), Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Adriaan P. IJzerman
- Division of Medicinal Chemistry,
Leiden Academic Centre for Drug Research (LACDR), Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
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17
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Yu Z, van Veldhoven JPD, 't Hart IME, Kopf AH, Heitman LH, IJzerman AP. Synthesis and biological evaluation of negative allosteric modulators of the Kv11.1(hERG) channel. Eur J Med Chem 2015; 106:50-9. [PMID: 26519929 DOI: 10.1016/j.ejmech.2015.10.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 10/14/2015] [Accepted: 10/16/2015] [Indexed: 01/13/2023]
Abstract
We synthesized and evaluated a series of compounds for their allosteric modulation at the Kv11.1 (hERG) channel. Most compounds were negative allosteric modulators of [(3)H]dofetilide binding to the channel, in particular 7f, 7h-j and 7p. Compounds 7f and 7p were the most potent negative allosteric modulators amongst all ligands, significantly increasing the dissociation rate of dofetilide in the radioligand kinetic binding assay, while remarkably reducing the affinities of dofetilide and astemizole in a competitive displacement assay. Additionally, both 7f and 7p displayed peculiar displacement characteristics with Hill coefficients significantly distinct from unity as shown by e.g., dofetilide, further indicative of their allosteric effects on dofetilide binding. Our findings in this investigation yielded several promising negative allosteric modulators for future functional and clinical research with respect to their antiarrhythmic propensities, either alone or in combination with known Kv11.1 blockers.
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Affiliation(s)
- Zhiyi Yu
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, 2300 RA Leiden, The Netherlands
| | - Jacobus P D van Veldhoven
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, 2300 RA Leiden, The Netherlands
| | - Ingrid M E 't Hart
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, 2300 RA Leiden, The Netherlands
| | - Adrian H Kopf
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, 2300 RA Leiden, The Netherlands
| | - Laura H Heitman
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, 2300 RA Leiden, The Netherlands
| | - Adriaan P IJzerman
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, 2300 RA Leiden, The Netherlands.
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18
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Guo D, Venhorst SN, Massink A, van Veldhoven JPD, Vauquelin G, IJzerman AP, Heitman LH. Molecular mechanism of allosteric modulation at GPCRs: insight from a binding kinetics study at the human A1 adenosine receptor. Br J Pharmacol 2014; 171:5295-312. [PMID: 25040887 PMCID: PMC4294041 DOI: 10.1111/bph.12836] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 06/27/2014] [Accepted: 07/03/2014] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND AND PURPOSE Many GPCRs can be allosterically modulated by small-molecule ligands. This modulation is best understood in terms of the kinetics of the ligand-receptor interaction. However, many current kinetic assays require at least the (radio)labelling of the orthosteric ligand, which is impractical for studying a range of ligands. Here, we describe the application of a so-called competition association assay at the adenosine A1 receptor for this purpose. EXPERIMENTAL APPROACH We used a competition association assay to examine the binding kinetics of several unlabelled orthosteric agonists of the A1 receptor in the absence or presence of two allosteric modulators. We also tested three bitopic ligands, in which an orthosteric and an allosteric pharmacophore were covalently linked with different spacer lengths. The relevance of the competition association assay for the binding kinetics of the bitopic ligands was also explored by analysing simulated data. KEY RESULTS The binding kinetics of an unlabelled orthosteric ligand were affected by the addition of an allosteric modulator and such effects were probe- and concentration-dependent. Covalently linking the orthosteric and allosteric pharmacophores into one bitopic molecule had a substantial effect on the overall on- or off-rate. CONCLUSION AND IMPLICATIONS The competition association assay is a useful tool for exploring the allosteric modulation of the human adenosine A1 receptor. This assay may have general applicability to study allosteric modulation at other GPCRs as well.
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Affiliation(s)
- Dong Guo
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research (LACDR), Leiden UniversityLeiden, The Netherlands
| | - Suzanne N Venhorst
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research (LACDR), Leiden UniversityLeiden, The Netherlands
| | - Arnault Massink
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research (LACDR), Leiden UniversityLeiden, The Netherlands
| | - Jacobus P D van Veldhoven
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research (LACDR), Leiden UniversityLeiden, The Netherlands
| | - Georges Vauquelin
- Institute for Molecular Biology and Biotechnology, Free University of Brussels (VUB)Brussel, Belgium
| | - Adriaan P IJzerman
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research (LACDR), Leiden UniversityLeiden, The Netherlands
| | - Laura H Heitman
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research (LACDR), Leiden UniversityLeiden, The Netherlands
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19
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Hill SJ, May LT, Kellam B, Woolard J. Allosteric interactions at adenosine A(1) and A(3) receptors: new insights into the role of small molecules and receptor dimerization. Br J Pharmacol 2014; 171:1102-13. [PMID: 24024783 DOI: 10.1111/bph.12345] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 07/09/2013] [Accepted: 07/12/2013] [Indexed: 12/22/2022] Open
Abstract
The purine nucleoside adenosine is present in all cells in tightly regulated concentrations. It is released under a variety of physiological and pathophysiological conditions to facilitate protection and regeneration of tissues. Adenosine acts via specific GPCRs to either stimulate cyclic AMP formation, as exemplified by Gs -protein-coupled adenosine receptors (A2A and A2B ), or inhibit AC activity, in the case of Gi/o -coupled adenosine receptors (A1 and A3 ). Recent advances in our understanding of GPCR structure have provided insights into the conformational changes that occur during receptor activation following binding of agonists to orthosteric (i.e. at the same binding site as an endogenous modulator) and allosteric regulators to allosteric sites (i.e. at a site that is topographically distinct from the endogenous modulator). Binding of drugs to allosteric sites may lead to changes in affinity or efficacy, and affords considerable potential for increased selectivity in new drug development. Herein, we provide an overview of the properties of selective allosteric regulators of the adenosine A1 and A3 receptors, focusing on the impact of receptor dimerization, mechanistic approaches to single-cell ligand-binding kinetics and the effects of A1 - and A3 -receptor allosteric modulators on in vivo pharmacology.
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Affiliation(s)
- Stephen J Hill
- Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, UK
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20
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Antonioli L, Csóka B, Fornai M, Colucci R, Kókai E, Blandizzi C, Haskó G. Adenosine and inflammation: what's new on the horizon? Drug Discov Today 2014; 19:1051-68. [DOI: 10.1016/j.drudis.2014.02.010] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 02/06/2014] [Accepted: 02/25/2014] [Indexed: 12/18/2022]
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21
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Corriden R, Kilpatrick LE, Kellam B, Briddon SJ, Hill SJ. Kinetic analysis of antagonist-occupied adenosine-A3 receptors within membrane microdomains of individual cells provides evidence of receptor dimerization and allosterism. FASEB J 2014; 28:4211-22. [PMID: 24970394 PMCID: PMC4202110 DOI: 10.1096/fj.13-247270] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
In our previous work, using a fluorescent adenosine-A3 receptor (A3AR) agonist and fluorescence correlation spectroscopy (FCS), we demonstrated high-affinity labeling of the active receptor (R*) conformation. In the current study, we used a fluorescent A3AR antagonist (CA200645) to study the binding characteristics of antagonist-occupied inactive receptor (R) conformations in membrane microdomains of individual cells. FCS analysis of CA200645-occupied A3ARs revealed 2 species, τD2 and τD3, that diffused at 2.29 ± 0.35 and 0.09 ± 0.03 μm(2)/s, respectively. FCS analysis of a green fluorescent protein (GFP)-tagged A3AR exhibited a single diffusing species (0.105 μm(2)/s). The binding of CA200645 to τD3 was antagonized by nanomolar concentrations of the A3 antagonist MRS 1220, but not by the agonist NECA (up to 300 nM), consistent with labeling of R. CA200645 normally dissociated slowly from the A3AR, but inclusion of xanthine amine congener (XAC) or VUF 5455 during washout markedly accelerated the reduction in the number of particles exhibiting τD3 characteristics. It is notable that this effect was accompanied by a significant increase in the number of particles with τD2 diffusion. These data show that FCS analysis of ligand-occupied receptors provides a unique means of monitoring ligand A3AR residence times that are significantly reduced as a consequence of allosteric interaction across the dimer interface
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Affiliation(s)
- Ross Corriden
- Institute of Cell Signalling, School of Life Sciences, Medical School, and
| | - Laura E Kilpatrick
- Institute of Cell Signalling, School of Life Sciences, Medical School, and
| | - Barrie Kellam
- School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Stephen J Briddon
- Institute of Cell Signalling, School of Life Sciences, Medical School, and
| | - Stephen J Hill
- Institute of Cell Signalling, School of Life Sciences, Medical School, and
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22
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Allosteric modulators of rhodopsin-like G protein-coupled receptors: opportunities in drug development. Pharmacol Ther 2012; 135:292-315. [PMID: 22728155 DOI: 10.1016/j.pharmthera.2012.06.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 06/07/2012] [Indexed: 11/21/2022]
Abstract
Rhodopsin-like (class A) G protein-coupled receptors (GPCRs) are one of the most important classes of drug targets. The discovery that these GPCRs can be allosterically modulated by small drug molecules has opened up new opportunities in drug development. It will allow the drugability of "difficult targets", such as GPCRs activated by large (glyco)proteins, or by very polar or highly lipophilic physiological agonists. Receptor subtype selectivity should be more easily achievable with allosteric than with orthosteric ligands. Allosteric modulation will allow a broad spectrum of pharmacological effects largely expanding that of orthosteric ligands. Furthermore, allosteric modulators may show an improved safety profile as compared to orthosteric ligands. Only recently, the explicit search for allosteric modulators has been started for only a few rhodopsin-like GPCRs. The first negative allosteric modulators (allosteric antagonists) of chemokine receptors, maraviroc (CCR5 receptor), used in HIV therapy, and plerixafor (CXCR4 receptor) for stem cell mobilization, have been approved as drugs. The development of allosteric modulators for rhodopsin-like GPCRs as novel drugs is still at an early stage; it appears highly promising.
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23
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Baraldi PG, Preti D, Borea PA, Varani K. Medicinal Chemistry of A3 Adenosine Receptor Modulators: Pharmacological Activities and Therapeutic Implications. J Med Chem 2012; 55:5676-703. [DOI: 10.1021/jm300087j] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Pier Giovanni Baraldi
- Dipartimento
di Scienze Farmaceutiche and ‡Dipartimento di Medicina Clinica e Sperimentale-Sezione
di Farmacologia, Università di Ferrara, 44121 Ferrara, Italy
| | - Delia Preti
- Dipartimento
di Scienze Farmaceutiche and ‡Dipartimento di Medicina Clinica e Sperimentale-Sezione
di Farmacologia, Università di Ferrara, 44121 Ferrara, Italy
| | - Pier Andrea Borea
- Dipartimento
di Scienze Farmaceutiche and ‡Dipartimento di Medicina Clinica e Sperimentale-Sezione
di Farmacologia, Università di Ferrara, 44121 Ferrara, Italy
| | - Katia Varani
- Dipartimento
di Scienze Farmaceutiche and ‡Dipartimento di Medicina Clinica e Sperimentale-Sezione
di Farmacologia, Università di Ferrara, 44121 Ferrara, Italy
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24
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Cheong SL, Federico S, Venkatesan G, Mandel AL, Shao YM, Moro S, Spalluto G, Pastorin G. The A3 adenosine receptor as multifaceted therapeutic target: pharmacology, medicinal chemistry, and in silico approaches. Med Res Rev 2011; 33:235-335. [PMID: 22095687 DOI: 10.1002/med.20254] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Adenosine is an ubiquitous local modulator that regulates various physiological and pathological functions by stimulating four membrane receptors, namely A(1), A(2A), A(2B), and A(3). Among these G protein-coupled receptors, the A(3) subtype is found mainly in the lung, liver, heart, eyes, and brain in our body. It has been associated with cerebroprotection and cardioprotection, as well as modulation of cellular growth upon its selective activation. On the other hand, its inhibition by selective antagonists has been reported to be potentially useful in the treatment of pathological conditions including glaucoma, inflammatory diseases, and cancer. In this review, we focused on the pharmacology and the therapeutic implications of the human (h)A(3) adenosine receptor (AR), together with an overview on the progress of hA(3) AR agonists, antagonists, allosteric modulators, and radioligands, as well as on the recent advances pertaining to the computational approaches (e.g., quantitative structure-activity relationships, homology modeling, molecular docking, and molecular dynamics simulations) applied to the modeling of hA(3) AR and drug design.
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Affiliation(s)
- Siew Lee Cheong
- Department of Pharmacy, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore
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25
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Du L, Gao ZG, Nithipatikom K, Ijzerman AP, Veldhoven JPDV, Jacobson KA, Gross GJ, Auchampach JA. Protection from myocardial ischemia/reperfusion injury by a positive allosteric modulator of the A₃ adenosine receptor. J Pharmacol Exp Ther 2011; 340:210-7. [PMID: 22011434 DOI: 10.1124/jpet.111.187559] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Adenosine is increased in ischemic tissues where it serves a protective role by activating adenosine receptors (ARs), including the A₃ AR subtype. We investigated the effect of N-{2-[(3,4-dichlorophenyl)amino]quinolin-4-yl}cyclohexanecarboxamide (LUF6096), a positive allosteric modulator of the A₃ AR, on infarct size in a barbital-anesthetized dog model of myocardial ischemia/reperfusion injury. Dogs were subjected to 60 min of coronary artery occlusion and 3 h of reperfusion. Infarct size was assessed by macrohistochemical staining. Three experimental groups were included in the study. Groups I and II received two doses of vehicle or LUF6096 (0.5 mg/kg i.v. bolus), one administered before ischemia and the other immediately before reperfusion. Group III received a single dose of LUF6096 (1 mg/kg i.v. bolus) immediately before reperfusion. In preliminary in vitro studies, LUF6096 was found to exert potent enhancing activity (EC₅₀ 114.3 ± 15.9 nM) with the canine A₃ AR in a guanosine 5'-[γ-[³⁵S]thio]triphosphate binding assay. LUF6096 increased the maximal efficacy of the partial A₃ AR agonist 2-chloro-N⁶-(3-iodobenzyl)adenosine-5'-N-methylcarboxamide and the native agonist adenosine more than 2-fold while producing a slight decrease in potency. In the dog studies, administration of LUF6096 had no effect on any hemodynamic parameter measured. Pretreatment with LUF6096 before coronary occlusion and during reperfusion in group II dogs produced a marked reduction in infarct size (∼50% reduction) compared with group I vehicle-treated dogs. An equivalent reduction in infarct size was observed when LUF6096 was administered immediately before reperfusion in group III dogs. This is the first study to demonstrate efficacy of an A₃ AR allosteric enhancer in an in vivo model of infarction.
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Affiliation(s)
- Lili Du
- Department of Pharmacology and the Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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26
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Fredholm BB, IJzerman AP, Jacobson KA, Linden J, Müller CE. International Union of Basic and Clinical Pharmacology. LXXXI. Nomenclature and classification of adenosine receptors--an update. Pharmacol Rev 2011; 63:1-34. [PMID: 21303899 PMCID: PMC3061413 DOI: 10.1124/pr.110.003285] [Citation(s) in RCA: 1025] [Impact Index Per Article: 78.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
In the 10 years since our previous International Union of Basic and Clinical Pharmacology report on the nomenclature and classification of adenosine receptors, no developments have led to major changes in the recommendations. However, there have been so many other developments that an update is needed. The fact that the structure of one of the adenosine receptors has recently been solved has already led to new ways of in silico screening of ligands. The evidence that adenosine receptors can form homo- and heteromultimers has accumulated, but the functional significance of such complexes remains unclear. The availability of mice with genetic modification of all the adenosine receptors has led to a clarification of the functional roles of adenosine, and to excellent means to study the specificity of drugs. There are also interesting associations between disease and structural variants in one or more of the adenosine receptors. Several new selective agonists and antagonists have become available. They provide improved possibilities for receptor classification. There are also developments hinting at the usefulness of allosteric modulators. Many drugs targeting adenosine receptors are in clinical trials, but the established therapeutic use is still very limited.
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Affiliation(s)
- Bertil B Fredholm
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
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27
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Jacobson KA, Gao ZG, Göblyös A, IJzerman AP. Allosteric modulation of purine and pyrimidine receptors. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2011; 61:187-220. [PMID: 21586360 PMCID: PMC3165024 DOI: 10.1016/b978-0-12-385526-8.00007-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Among the purine and pyrimidine receptors, the discovery of small molecular allosteric modulators has been most highly advanced for the A(1) and A(3) adenosine receptors (ARs). These AR modulators have allosteric effects that are structurally separated from the orthosteric effects in SAR studies. The benzoylthiophene derivatives tend to act as allosteric agonists as well as selective positive allosteric modulators (PAMs) of the A(1) AR. A 2-amino-3-aroylthiophene derivative T-62 has been under development as a PAM of the A(1) AR for the treatment of chronic pain. Several structurally distinct classes of allosteric modulators of the human A(3) AR have been reported: 3-(2-pyridinyl)isoquinolines, 2,4-disubstituted quinolines, 1H-imidazo-[4,5-c]quinolin-4-amines, endocannabinoid 2-arachidonylglycerol, and the food dye Brilliant Black BN. Site-directed mutagenesis of A(1) and A(3) ARs has identified residues associated with the allosteric effect, distinct from those that affect orthosteric binding. A few small molecular allosteric modulators have been reported for several of the P2X ligand-gated ion channels and the G protein-coupled P2Y receptor nucleotides. Metal ion modulation of the P2X receptors has been extensively explored. The allosteric approach to modulation of purine and pyrimidine receptors looks promising for development of drugs that are event and site specific in action.
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Affiliation(s)
- Kenneth A. Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Anikó Göblyös
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA, Leiden, The Netherlands
| | - Adriaan P. IJzerman
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA, Leiden, The Netherlands
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28
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The crystallographic structure of the human adenosine A2A receptor in a high-affinity antagonist-bound state: implications for GPCR drug screening and design. Curr Opin Struct Biol 2010; 20:401-14. [DOI: 10.1016/j.sbi.2010.05.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Accepted: 05/09/2010] [Indexed: 01/28/2023]
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29
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De Amici M, Dallanoce C, Holzgrabe U, Tränkle C, Mohr K. Allosteric ligands for G protein-coupled receptors: a novel strategy with attractive therapeutic opportunities. Med Res Rev 2010; 30:463-549. [PMID: 19557759 DOI: 10.1002/med.20166] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Allosteric receptor ligands bind to a recognition site that is distinct from the binding site of the endogenous messenger molecule. As a consequence, allosteric agents may attach to receptors that are already transmitter-bound. Ternary complex formation opens an avenue to qualitatively new drug actions at G protein-coupled receptors (GPCRs), in particular receptor subtype selective potentiation of endogenous transmitter action. Consequently, suitable exploitation of allosteric recognition sites as alternative molecular targets could pave the way to a drug discovery paradigm different from those aimed at mimicking or blocking the effects of endogenous (orthosteric) receptor activators. The number of allosteric ligands reported to modulate GPCR function is steadily increasing and some have already reached routine clinical use. This review aims at introducing into this fascinating field of drug discovery and at providing an overview about the achievements that have already been made. Various case examples will be discussed in the framework of GPCR classification (family A, B, and C receptors). In addition, the behavior at muscarinic receptors of hybrid derivatives incorporating both an allosteric and an orthosteric fragment in a common molecular skeleton will be illustrated.
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Affiliation(s)
- Marco De Amici
- Department of Pharmaceutical Sciences Pietro Pratesi, University of Milan, via Mangiagalli 25, 20133 Milano, Italy.
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30
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Göblyös A, Ijzerman AP. Allosteric modulation of adenosine receptors. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1808:1309-18. [PMID: 20599682 DOI: 10.1016/j.bbamem.2010.06.013] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Revised: 06/10/2010] [Accepted: 06/10/2010] [Indexed: 10/19/2022]
Abstract
Allosteric ligands for G protein-coupled receptors (GPCRs) may alter receptor conformations induced by an orthosteric ligand. These modulators can thus fine-tune classical pharmacological responses. In this review we will describe efforts to synthesize and characterize allosteric modulators for one particular GPCR subfamily, the adenosine receptors. There are four subtypes of these receptors: A(1), A(2A), A(2B) and A(3). Allosteric enhancers for the adenosine A(1) receptor may have anti-arrythmic and anti-lipolytic activity. They may also act as analgesics and neuroprotective agents. A(3) allosteric enhancers are thought to be beneficial in ischemic conditions or as antitumor agents. We will summarize recent developments regarding the medicinal chemistry of such compounds. Most data have been and are published about the adenosine A(1) and A(3) receptor, whereas limited or no information is available for the A(2A) and A(2B) receptor, respectively. Receptor mutation studies are also discussed, as they may shed light on the localization of the allosteric binding sites. This article is part of a Special Issue entitled: "Adenosine Receptors".
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Affiliation(s)
- Anikó Göblyös
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Leiden, The Netherlands
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31
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May LT, Self TJ, Briddon SJ, Hill SJ. The effect of allosteric modulators on the kinetics of agonist-G protein-coupled receptor interactions in single living cells. Mol Pharmacol 2010; 78:511-23. [PMID: 20571079 DOI: 10.1124/mol.110.064493] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Allosteric binding sites on adenosine -A(1) and -A(3) receptors represent attractive therapeutic targets for amplifying, in a spatially and temporally selective manner, the tissue protective actions of endogenous adenosine. This study has directly quantified the kinetics of agonist/G protein-coupled receptor interactions at the single-cell level, reflecting the physiological situation in which intracellular signaling proteins can exert major allosteric effects on agonist-receptor interactions. The association and dissociation rate constants at both A(1) and A(3) receptors, and therefore the affinity of the fluorescent adenosine derivative ABA-X-BY630 (structure appears in J Med Chem 50:782-793, 2007), were concentration-independent. The equilibrium dissociation constants of ABA-X-BY630 at A(1) and A(3) receptors were approximately 50 and 10 nM, respectively, suggesting that, even in live cells, low agonist concentrations predominantly detect high-affinity receptor states. At A(1) receptors, the dissociation of ABA-X-BY630 (30 nM) was significantly faster in the absence (k(off) = 1.95 +/- 0.09 min(-1)) compared with the presence of the allosteric enhancer (2-amino-4,5-dimethyl-3-thienyl)(3-(trifluoromethyl)phenyl)-methanone (PD81,723; 10 microM; k(off) = 0.80 +/- 0.03 min(-1)) and allosteric inhibitor 4-methoxy-N-(7-methyl-3-(2-pyridinyl)-1-isoquinolinyl)benzamide (VUF5455; 1 microM; k(off) = 1.48 +/- 0.16 min(-1)). In contrast, ABA-X-BY630 dissociation from A(3) receptors was significantly slower in the absence (k(off) = 0.78 +/- 0.18 min(-1)) than in the presence of the allosteric inhibitors VUF5455 (1 microM; k(off) = 3.15 +/- 0.12 min(-1)) and PD81,723 (10 microM; k(off) = 2.46 +/- 0.18 min(-1)). An allosteric mechanism of action has previously not been identified for PD81,723 at the A(3) receptor or VUF5455 at the A(1) receptor. Furthermore, the marked enhancement in fluorescent agonist dissociation by VUF5455 in living cells contrasts previous observations from broken cell preparations and emphasizes the need to study the allosteric regulation of agonist binding in living cells.
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Affiliation(s)
- Lauren T May
- The Institute of Cell Signalling, School of Biomedical Sciences, the University of Nottingham, Nottingham, United Kingdom
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32
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May LT, Briddon SJ, Hill SJ. Antagonist selective modulation of adenosine A1 and A3 receptor pharmacology by the food dye Brilliant Black BN: evidence for allosteric interactions. Mol Pharmacol 2010; 77:678-86. [PMID: 20086038 DOI: 10.1124/mol.109.063065] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Allosteric binding sites on the adenosine receptor family represent potential therapeutic targets for a number of conditions involving metabolic stress. This study has identified Brilliant Black BN as a novel allosteric modulator of the adenosine A(1) and A(3) receptors. In addition to being a food dye and pharmaceutical excipient, Brilliant Black BN is commonly used within calcium mobilization assays to quench extracellular fluorescence. Brilliant Black BN (5-500 microM) had no significant effect on the calcium mobilization stimulated by the nonselective adenosine receptor agonist 5'-(N-ethylcarboxamido)adenosine in Chinese hamster ovary cells stably transfected with the human adenosine A(1) or A(3) receptor. Likewise, calcium mobilization and radioligand binding assays found that Brilliant Black BN (5-500 microM) did not significantly influence the antagonism mediated by 8-cyclopentyl-1,3-dipropylxanthine (100 nM) at the A(1) receptor. In contrast, the affinity of N-[9-chloro-2-(2-furanyl)[1,2,4]-triazolo[1,5-c]quinazolin-5-yl]benzene acetamide (MRS1220) at the A(3) receptor and xanthine amine congener (XAC) and XAC-X-BY630 at the A(1) and A(3) receptors was significantly decreased in the presence of 500 muM Brilliant Black BN. A reduction in XAC potency at the A(1) and A(3) receptor was achieved within 1 min of Brilliant Black BN addition, despite receptors having been pre-equilibrated with antagonist. Dissociation kinetics of the fluorescent XAC derivative, XAC-X-BY630, revealed that the decrease in affinity is probably due to a significant increase in dissociation rate of the antagonist in the presence of Brilliant Black BN. Taken together, these results suggest that Brilliant Black BN can act allosterically to modify ligand affinity at A(1) and A(3) receptors.
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Affiliation(s)
- L T May
- Institute of Cell Signaling, The University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH, UK
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33
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Kim Y, de Castro S, Gao ZG, Ijzerman AP, Jacobson KA. Novel 2- and 4-substituted 1H-imidazo[4,5-c]quinolin-4-amine derivatives as allosteric modulators of the A3 adenosine receptor. J Med Chem 2009; 52:2098-108. [PMID: 19284749 PMCID: PMC2765805 DOI: 10.1021/jm801659w] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
4-Arylamino and 2- cycloalkyl (including amino substitution) modifications were made in a series of 1H-imidazo[4,5-c]quinolin-4-amine derivatives as allosteric modulators of the human A(3) adenosine receptor (AR). In addition to allosteric modulation of the maximum functional efficacy (in [(35)S]GTPgammaS G protein binding assay) of the A(3)AR agonist Cl-IB-MECA (15), some analogues also weakly inhibited equilibrium radioligand binding at ARs. 4-(3,5-Dichlorophenylamino) (6) or 2-(1-adamantyl) (20) substitution produced allosteric enhancement (twice the maximal agonist efficacy), with minimal inhibition of orthosteric AR binding. 2-(4-Tetrahydropyranyl) substitution abolished allosteric enhancement but preserved inhibition of orthosteric binding. Introduction of nitrogen in the six-membered ring at the 2 position, to improve aqueous solubility and provide a derivatization site, greatly reduced the allosteric enhancement. 2-(4-(Benzoylamino)cyclohexyl) analogues 23 and 24 were weak negative A(3)AR modulators. Thus, consistent with previous findings, the allosteric and orthosteric inhibitory A(3)AR effects in imidazoquinolines are structurally separable, suggesting the possible design of additional derivatives with enhanced positive or negative allosteric A(3)AR activity and improved selectivity in comparison to inhibition of orthosteric binding.
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Affiliation(s)
- Yoonkyung Kim
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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34
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Heitman LH, Göblyös A, Zweemer AM, Bakker R, Mulder-Krieger T, van Veldhoven JPD, de Vries H, Brussee J, IJzerman AP. A Series of 2,4-Disubstituted Quinolines as a New Class of Allosteric Enhancers of the Adenosine A3 Receptor. J Med Chem 2009; 52:926-31. [DOI: 10.1021/jm8014052] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Laura H. Heitman
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Anikó Göblyös
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Annelien M. Zweemer
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Renée Bakker
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Thea Mulder-Krieger
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Jacobus P. D. van Veldhoven
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Henk de Vries
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Johannes Brussee
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Adriaan P. IJzerman
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
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35
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Giorgi I, Biagi G, Bianucci AM, Borghini A, Livi O, Leonardi M, Pietra D, Calderone V, Martelli A. N6-1,3-Diphenylurea derivatives of 2-phenyl-9-benzyladenines and 8-azaadenines: Synthesis and biological evaluation as allosteric modulators of A2A adenosine receptors. Eur J Med Chem 2008; 43:1639-47. [DOI: 10.1016/j.ejmech.2007.10.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2006] [Revised: 10/15/2007] [Accepted: 10/16/2007] [Indexed: 10/22/2022]
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36
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Abstract
Allosteric modulators for adenosine receptors may have potential therapeutic advantage over orthosteric ligands. Allosteric enhancers at the adenosine A1 receptor have been linked to antiarrhythmic and antilipolytic activity. They may also have therapeutic potential as analgesics and neuroprotective agents. A3 allosteric enhancers are postulated to be useful against ischemic conditions or as antitumor agents. In this review, we address recent developments regarding the medicinal chemistry of such compounds. Most efforts have been and are directed toward adenosine A1 and A3 receptors, whereas limited or no information is available for A2A and A2B receptors. We also discuss some findings, mostly receptor mutation studies, regarding localization of the allosteric binding sites on the receptors.
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37
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Abstract
The past decade has witnessed a significant growth in the identification of allosteric modulators of G protein-coupled receptors (GPCRs), i.e., ligands that interact with binding sites that are topographically distinct from the orthosteric site recognized by the receptor's endogenous agonist. Because of their ability to modulate receptor conformations in the presence of orthosteric ligand, allosteric modulators can "fine-tune" classical pharmacological responses. This is advantageous in terms of a potential for engendering greater GPCR subtype-selectivity, but represents a significant challenge for detecting and validating allosteric behaviors. Although allosteric sites need not have evolved to accommodate endogenous ligands, there are a number of examples of where such modulators have been shown to contribute to physiological or pathophysiological processes. Studies are also beginning to unravel the structural basis of allosteric modulation of GPCRs. It remains to be determined whether such modulation represents interactions within monomers versus across dimers.
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Affiliation(s)
- Lauren T May
- Department of Pharmacology, University of Melbourne, 3010 Parkville, Victoria
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Bhattacharya S, Youkey R, Ghartey K, Leonard M, Linden J, Tucker A. The allosteric enhancer PD81,723 increases chimaeric A1/A2A adenosine receptor coupling with Gs. Biochem J 2006; 396:139-46. [PMID: 16390330 PMCID: PMC1449996 DOI: 10.1042/bj20051422] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PD81,723 {(2-amino-4,5-dimethyl-3-thienyl)-[3-(trifluromethyl)-phenyl]methanone} is a selective allosteric enhancer of the G(i)-coupled A1 AR (adenosine receptor) that is without effect on G(s)-coupled A2A ARs. PD81,723 elicits a decrease in the dissociation kinetics of A1 AR agonist radioligands and an increase in functional agonist potency. In the present study, we sought to determine whether enhancer sensitivity is dependent on coupling domains or G-protein specificity of the A1 AR. Using six chimaeric A1/A2A ARs, we show that the allosteric effect of PD81,723 is maintained in a chimaera in which the predominant G-protein-coupling domain of the A1 receptor, the 3ICL (third intracellular loop), is replaced with A2A sequence. These chimaeric receptors are dually coupled with G(s) and G(i), and PD81,723 increases the potency of N6-cyclopentyladenosine to augment cAMP accumulation with or without pretreatment of cells with pertussis toxin. Thus PD81,723 has similar functional effects on chimaeric receptors with A1 transmembrane sequences that couple with G(i) or G(s). This is the first demonstration that an allosteric regulator can function in the context of a switch in G-protein-coupling specificity. There is no enhancement by PD81,723 of G(i)-coupled A2A chimaeric receptors with A1 sequence replacing A2A sequence in the 3ICL. The results suggest that the recognition site for PD81,723 is on the A1 receptor and that the enhancer acts to directly stabilize the receptor to a conformational state capable of coupling with G(i) or G(s).
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MESH Headings
- Adenosine/analogs & derivatives
- Adenosine/pharmacology
- Adrenergic alpha-Agonists/pharmacology
- Adrenergic alpha-Antagonists/pharmacology
- Allosteric Regulation/drug effects
- Animals
- Cell Line
- Cyclic AMP/metabolism
- Dogs
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- GTP-Binding Protein alpha Subunits, Gs/metabolism
- Humans
- Iodobenzenes/pharmacology
- Kidney/cytology
- Protein Conformation
- Protein Interaction Mapping
- Protein Structure, Tertiary
- Radioligand Assay
- Receptor, Adenosine A1/chemistry
- Receptor, Adenosine A1/drug effects
- Receptor, Adenosine A1/genetics
- Receptor, Adenosine A1/metabolism
- Receptor, Adenosine A2A/chemistry
- Receptor, Adenosine A2A/drug effects
- Receptor, Adenosine A2A/genetics
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/drug effects
- Recombinant Fusion Proteins/metabolism
- Thiophenes/pharmacology
- Transfection
- Xanthines/pharmacology
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Affiliation(s)
- Samita Bhattacharya
- *Department of Internal Medicine, Cardiovascular Division, University of Virginia Health Sciences Center, Charlottesville, VA 22908, U.S.A
| | - Rebecca L. Youkey
- *Department of Internal Medicine, Cardiovascular Division, University of Virginia Health Sciences Center, Charlottesville, VA 22908, U.S.A
| | - Kobina Ghartey
- *Department of Internal Medicine, Cardiovascular Division, University of Virginia Health Sciences Center, Charlottesville, VA 22908, U.S.A
| | - Matthew Leonard
- *Department of Internal Medicine, Cardiovascular Division, University of Virginia Health Sciences Center, Charlottesville, VA 22908, U.S.A
| | - Joel Linden
- *Department of Internal Medicine, Cardiovascular Division, University of Virginia Health Sciences Center, Charlottesville, VA 22908, U.S.A
- †Department of Molecular Physiology and Biological Physics, University of Virginia Health Sciences Center, Charlottesville, VA 22908, U.S.A
- ‡Cardiovascular Research Center, University of Virginia Health Sciences Center, Charlottesville, VA 22908, U.S.A
| | - Amy L. Tucker
- *Department of Internal Medicine, Cardiovascular Division, University of Virginia Health Sciences Center, Charlottesville, VA 22908, U.S.A
- †Department of Molecular Physiology and Biological Physics, University of Virginia Health Sciences Center, Charlottesville, VA 22908, U.S.A
- ‡Cardiovascular Research Center, University of Virginia Health Sciences Center, Charlottesville, VA 22908, U.S.A
- To whom correspondence should be addressed, at Box 801394, MR5 Room G219, University of Virginia Health System, Charlottesville, VA 22908, U.S.A. (email )
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Schwartz TW, Holst B. Ago-allosteric modulation and other types of allostery in dimeric 7TM receptors. J Recept Signal Transduct Res 2006; 26:107-28. [PMID: 16595341 DOI: 10.1080/10799890600567570] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Conventionally, an allosteric modulator is neutral in respect of efficacy and binds to a receptor site distant from the orthosteric site of the endogenous agonist. However, recently compounds being ago-allosteric modulators have been described i.e., compounds acting both as agonists on their own and as enhancers for the endogenous agonists in both increasing agonist potency and providing additive efficacy-superagonism. The additive efficacy can also be observed with agonists, which are neutral or even negative modulators of the potency of the endogenous ligand. Based on the prevailing dimeric concept for 7TM receptors, it is proposed that the ago-allosteric modulators bind in the orthosteric binding site, but-importantly-in the "other" or allosteric protomer of the dimer. Hereby, they can act both as additive co-agonists, and through intermolecular cooperative effects between the protomers, they may influence the potency of the endogenous agonist. It is of interest that at least some endogenous agonists can only occupy one protomer of a dimeric 7TM receptor complex at a time and thereby they leave the orthosteric binding site in the allosteric protomer free, potentially for binding of exogenous, allosteric modulators. If the allosteric modulator is an agonist, it is an ago-allosteric modulator; if it is neutral, it is a classical enhancer. Molecular mapping in hetero-dimeric class-C receptors, where the endogenous agonist clearly binds only in one protomer, supports the notion that allosteric modulators can act through binding in the "other" protomer. It is suggested that for the in vivo, clinical setting a positive ago-allosteric modulator should be the preferred agonist drug.
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Affiliation(s)
- Thue W Schwartz
- Laboratory for Molecular Pharmacology, Department of Pharmacology, University of Copenhagen and 7TM Pharma A/S, Hørsholm, Denmark.
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Abstract
Allosteric modulation of membrane receptors has been intensively studied in the past three decades and is now considered to be an important indirect mechanism for the control of receptor function. The allosteric site on the GABA(A) receptor is the target for the most widely prescribed sleep medicines, the benzodiazepines. Cinacalcet, an allosteric enhancer of the calcium-sensing receptor, is used to treat secondary hyperparathyroidism. Allosteric ligands might be especially valuable to control receptors for which the design of selective orthosteric agonists or antagonists has been elusive, such as muscarinic acetylcholine receptors.
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Affiliation(s)
- Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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Pastorin G, Bolcato C, Cacciari B, Kachler S, Klotz KN, Montopoli C, Moro S, Spalluto G. Synthesis, biological and modeling studies of 1,3-di-n-propyl-2,4-dioxo-6-methyl-8-(substituted) 1,2,3,4-tetrahydro [1,2,4]-triazolo [3,4-f]-purines as adenosine receptor antagonists. ACTA ACUST UNITED AC 2006; 60:643-51. [PMID: 15961085 DOI: 10.1016/j.farmac.2005.04.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2005] [Revised: 04/27/2005] [Accepted: 04/28/2005] [Indexed: 10/25/2022]
Abstract
A new series of potential adenosine receptor antagonists with a [1,2,4]-triazolo-[3,4-f]-purine structure bearing at the 1 and 3 position n-propyl groups have been synthesized, and their affinities at the four human adenosine receptor subtypes (A(1), A(2A), A(2B) and A(3)) have been evaluated. In this case the presence of n-propyl groups seems to induce potency at the A(2A) and A(3) adenosine receptor subtypes as opposed to our previously reported series bearing methyl substituents at the 1 and 3 positions. In particular the non-acylated derivative 17 showed affinity at these two receptor subtypes in the micromolar range. Indeed, preliminary molecular modeling investigations according to the experimental binding data indicate a modest steric and electrostatic antagonist-receptor complementarity.
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Affiliation(s)
- G Pastorin
- Dipartimento di Scienze Farmaceutiche, Università di Trieste, Piazzale Europa 1, 34127 Trieste, Italy
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Moro S, Bacilieri M, Deflorian F, Spalluto G. G protein-coupled receptors as challenging druggable targets: insights from in silico studies. NEW J CHEM 2006. [DOI: 10.1039/b516389g] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Pastorin G, Bolcato C, Cacciari B, Kachler S, Klotz KN, Montopoli C, Moro S, Spalluto G. Synthesis, biological studies and molecular modeling investigation of 1,3-dimethyl-2,4-dioxo-6-methyl-8-(substituted) 1,2,3,4-tetrahydro [1,2,4]-triazolo [3,4-f]-purines as potential adenosine receptor antagonists. ACTA ACUST UNITED AC 2005; 60:299-306. [PMID: 15848204 DOI: 10.1016/j.farmac.2005.01.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2004] [Revised: 01/12/2005] [Accepted: 01/15/2005] [Indexed: 11/18/2022]
Abstract
A new series of potential adenosine receptor antagonists with a [1,2,4]-triazolo-[3,4-f]-purine structure have been synthesized, and their affinities at the four adenosine receptor subtypes (A1, A2A, A2B and A3) have been evaluated. The design was based on the demonstrated approach to novel A3 adenosine receptor antagonists of adding a third ring to the xanthine structure. Unfortunately, all the synthesized compounds were completely inactive at all four adenosine receptor subtypes independently of their substitutions. Preliminary molecular modeling investigation has demonstrated that only a low degree of steric and electrostatic complementarity has been observed for all the new synthesized triazolo-purines with respect to other structurally related A3 receptor antagonists. This analysis yielded valuable information about structure-activity relationships and further design of potential adenosine receptor antagonists.
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Affiliation(s)
- Giorgia Pastorin
- Dipartimento di Scienze Farmaceutiche, Università di Trieste, Piazzale Europa 1, I-34127, Trieste, Italy
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Moro S, Spalluto G, Jacobson KA. Techniques: Recent developments in computer-aided engineering of GPCR ligands using the human adenosine A3 receptor as an example. Trends Pharmacol Sci 2005; 26:44-51. [PMID: 15629204 DOI: 10.1016/j.tips.2004.11.006] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
G-protein-coupled receptors (GPCRs) represent the largest known family of signal-transducing molecules, and convey signals for light and many extracellular regulatory molecules. GPCRs are dysfunctional or dysregulated in several human diseases and are estimated to be the targets of >40% of the drugs used in clinical medicine today. The crystal structure of rhodopsin provides the first information on the three-dimensional structure of GPCRs, which now supports homology modeling studies and structure-based drug-design approaches. In this article, we review recent work on adenosine receptors, a family of GPCRs, and, in particular, on adenosine A(3) receptor antagonists. We focus on an iterative, bi-directional approach in which models are used to generate hypotheses that are tested by experimentation; the experimental findings are, in turn, used to refine the model. The success of this approach is due to the synergistic interaction between theory and experimentation.
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Affiliation(s)
- Stefano Moro
- Molecular Modeling Section, Dipartimento di Scienze Farmaceutiche, Università di Padova, Via Marzolo 5, I-35131 Padova, Italy.
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Soudijn W, Van Wijngaarden I, IJzerman AP. Allosteric modulation of G protein-coupled receptors: perspectives and recent developments. Drug Discov Today 2004; 9:752-8. [PMID: 15450241 DOI: 10.1016/s1359-6446(04)03220-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Allosteric modulation of G protein-coupled receptors has recently been recognized as an alternative approach to gain selectivity in drug action. In this overview, allosteric modulators that enhance or diminish the effects of (endogenous) agonists or antagonists on a variety of G protein-coupled receptors are described. Emphasis is placed on the latest developments in this research area, including data on the first clinical studies. It appears that all three major classes of G protein-coupled receptors (A, B and C) are amenable to allosteric modulation by small molecules. This constitutes an attractive and novel means to identify new leads in the drug discovery process. However, it requires a re-engineering of the majority of current assays. Finally, it is suggested to introduce the term 'non-competitive agonism' or 'allosteric agonism' next to allosteric modulation.
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Affiliation(s)
- Willem Soudijn
- Division of Medicinal Chemistry Leiden/Amsterdam Center for Drug Research Leiden University PO Box 9502, 2300RA Leiden, The Netherlands
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Gao ZG, Gross AS, Jacobson KA. Effects of the allosteric modulator SCH-202676 on adenosine and P2Y receptors. Life Sci 2004; 74:3173-80. [PMID: 15081581 PMCID: PMC4367543 DOI: 10.1016/j.lfs.2003.11.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2003] [Accepted: 11/21/2003] [Indexed: 11/16/2022]
Abstract
The G protein-coupled receptor allosteric modulator SCH-202676 (N-(2,3-diphenyl-1,2,4-thiadiazol-5-(2H)-ylidene)methanamine), which affects a wide range of structurally unrelated G protein-coupled receptors, has highly divergent effects on purine receptors. SCH-202676 inhibited radioligand binding to human adenosine A(1), A(2A), and A(3) receptors (IC(50) = 0.5-0.8 microM) and affected dissociation kinetics, but at the human P2Y(1) nucleotide receptor it had no effect. SCH-202676 (10 microM) selectively accelerated agonist dissociation at adenosine A(3) receptors and either slowed (adenosine A(1) receptors) or accelerated (adenosine A(2A) receptors) antagonist dissociation. Thus, SCH-202676 differentially modulated A(1), A(2A), and A(3) receptors as well as agonist- and antagonist-occupied receptors.
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Affiliation(s)
- Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, Bldg. 8A, Rm. B1A-19, Bethesda, MD 20892-0810, USA
| | - Ariel S. Gross
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, Bldg. 8A, Rm. B1A-19, Bethesda, MD 20892-0810, USA
| | - Kenneth A. Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, Bldg. 8A, Rm. B1A-19, Bethesda, MD 20892-0810, USA
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Jensen AA, Spalding TA. Allosteric modulation of G-protein coupled receptors. Eur J Pharm Sci 2004; 21:407-20. [PMID: 14998571 DOI: 10.1016/j.ejps.2003.11.007] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2003] [Revised: 11/17/2003] [Accepted: 11/17/2003] [Indexed: 10/26/2022]
Abstract
The superfamily of G-protein coupled receptors (GPCRs) has more than 1000 members and is the largest family of proteins in the body. GPCRs mediate signalling of stimuli as diverse as light, ions, small molecules, peptides and proteins and are the targets for many pharmaceuticals. Most GPCR ligands are believed to activate (agonists) or inhibit (competitive antagonists) receptor signalling by binding the receptor at the same site as the endogenous agonist, the orthosteric site. In contrast, allosteric ligands modulate receptor function by binding to different regions in the receptor, allosteric sites. In recent years, combinatorial chemistry and high throughput screening have helped identify several allosteric GPCR modulators with novel structures, several of which already have become valuable pharmacological tools and may be candidates for clinical testing in the near future. This mini review outlines the current status and perspectives of allosteric modulation of GPCR function with emphasis on the pharmacology of endogenous and synthesised modulators, their receptor interactions and the therapeutic prospects of allosteric ligands compared to orthosteric ligands.
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Affiliation(s)
- Anders A Jensen
- Department of Medicinal Chemistry, The Danish University of Pharmaceutical Sciences, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
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Meno JR, Higashi H, Cambray AJ, Zhou J, D'Ambrosio R, Winn HR. Hippocampal injury and neurobehavioral deficits are improved by PD 81,723 following hyperglycemic cerebral ischemia. Exp Neurol 2003; 183:188-96. [PMID: 12957503 DOI: 10.1016/s0014-4886(03)00162-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We investigated the effects of PD 81,723, an allosteric enhancer for the adenosine A(1) receptor subtype, on hippocampal injury and Morris water maze (MWM) performance following hyperglycemic cerebral ischemia and reperfusion (4-VO, 10 min) in the rat. PD 81,723 (3 or 10 mg/kg) or the equivalent volume of saline was administered intraperitoneally 30 min prior to ischemia. Moderate hyperglycemia was achieved by administration of D-glucose (3g/kg, i.p.) 15 min prior to induction of ischemia. Morris water maze trials were performed on the 6th, 7th, and 8th days after the ischemic insult. The rat brains were sectioned (8 microm), stained with cresyl violet/acid fuchsin, and evaluated for hippocampal ischemic injury by an experimenter blinded to the treatment conditions. At the higher dose, PD 81,723 (10 mg/kg) had no effect on hippocampal injury or MWM performance following hyperglycemic ischemia compared to corresponding saline-treated animals. In contrast, a lower dose of PD 81,723 (3 mg/kg) resulted in significant (P < 0.05, n = 8) reduction of hippocampal injury following hyperglycemic ischemia. Furthermore, corresponding Morris water maze performance (latency, learning index, and cumulative distance swum) was significantly improved by PD 81,723 (P < 0.05, n = 8). The results of the present study suggest that, in the presence of PD 81,723, an A(1) allosteric enhancer, endogenously produced adenosine is sufficient to exert significant neuroprotection during hyperglycemic ischemia. Moreover, the present study provides further evidence for a neuromodulatory role of adenosine during hyperglycemic ischemia.
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Affiliation(s)
- Joseph R Meno
- Department of Neurological Surgery, University of Washington, Seattle, WA 98104, USA.
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Gao ZG, Blaustein JB, Gross AS, Melman N, Jacobson KA. N6-Substituted adenosine derivatives: selectivity, efficacy, and species differences at A3 adenosine receptors. Biochem Pharmacol 2003; 65:1675-84. [PMID: 12754103 PMCID: PMC3142561 DOI: 10.1016/s0006-2952(03)00153-9] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The activation of the human A(3) adenosine receptor (AR) by a wide range of N(6)-substituted adenosine derivatives was studied in intact CHO cells stably expressing this receptor. Selectivity of binding at rat and human ARs was also determined. Among N(6)-alkyl substitutions, small N(6)-alkyl groups were associated with selectivity for human A(3)ARs vs. rat A(3)ARs, and multiple points of branching were associated with decreased hA(3)AR efficacy. N(6)-Cycloalkyl-substituted adenosines were full (</=5 carbons) or partial (>/=6 carbons) hA(3)AR agonists. N(6)-(endo-Norbornyl)adenosine 13 was the most selective for both rat and human A(1)ARs. Numerous N(6)-arylmethyl analogues, including substituted benzyl, tended to be more potent in binding to A(1) and A(3) vs. A(2A)ARs (with variable degrees of partial to full A(3)AR agonisms). A chloro substituent decreased the efficacy depending on its position on the benzyl ring. The A(3)AR affinity and efficacy of N(6)-arylethyl adenosines depended highly on stereochemistry, steric bulk, and ring constraints. Stereoselectivity of binding was demonstrated for N(6)-(R-1-phenylethyl)adenosine vs. N(6)-(S-1-phenylethyl)adenosine, as well as for the N(6)-(1-phenyl-2-pentyl)adenosine, at the rat, but not human A(3)AR. Interestingly, DPMA, a potent agonist for the A(2A)AR (K(i)=4nM), was demonstrated to be a moderately potent antagonist for the human A(3)AR (K(i)=106nM). N(6)-[(1S,2R)-2-Phenyl-1-cyclopropyl]adenosine 48 was 1100-fold more potent in binding to human (K(i)=0.63nM) than rat A(3)ARs. Dual acting A(1)/A(3) agonists (N(6)-3-chlorobenzyl- 29, N(6)-(S-1-phenylethyl)- 39, and 2-chloro-N(6)-(R-phenylisopropyl)adenosine 53) might be useful for cardioprotection.
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Affiliation(s)
| | | | | | | | - Kenneth A. Jacobson
- Corresponding author. Tel.: +1-301-496-9024; fax: +1-301-480-8422. (K.A. Jacobson)
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