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Toyoda Y, Zhu A, Kong F, Shan S, Zhao J, Wang N, Sun X, Zhang L, Yan C, Kobilka BK, Liu X. Structural basis of α 1A-adrenergic receptor activation and recognition by an extracellular nanobody. Nat Commun 2023; 14:3655. [PMID: 37339967 DOI: 10.1038/s41467-023-39310-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 06/07/2023] [Indexed: 06/22/2023] Open
Abstract
The α1A-adrenergic receptor (α1AAR) belongs to the family of G protein-coupled receptors that respond to adrenaline and noradrenaline. α1AAR is involved in smooth muscle contraction and cognitive function. Here, we present three cryo-electron microscopy structures of human α1AAR bound to the endogenous agonist noradrenaline, its selective agonist oxymetazoline, and the antagonist tamsulosin, with resolutions range from 2.9 Å to 3.5 Å. Our active and inactive α1AAR structures reveal the activation mechanism and distinct ligand binding modes for noradrenaline compared with other adrenergic receptor subtypes. In addition, we identified a nanobody that preferentially binds to the extracellular vestibule of α1AAR when bound to the selective agonist oxymetazoline. These results should facilitate the design of more selective therapeutic drugs targeting both orthosteric and allosteric sites in this receptor family.
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Affiliation(s)
- Yosuke Toyoda
- School of Medicine, Tsinghua University, Beijing, 100084, China.
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing, 100084, China.
- Institute for Integrated Cell-Material Sciences, Institute for Advanced Study, Kyoto University, Kyoto, 606-8501, Japan.
| | - Angqi Zhu
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing, 100084, China
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Fang Kong
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing, 100084, China
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Sisi Shan
- School of Medicine, Tsinghua University, Beijing, 100084, China
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing, 100084, China
- NexVac Research Center, Comprehensive AIDS Research Center, Center for Infectious Disease Research, Tsinghua University, Beijing, 100084, China
| | - Jiawei Zhao
- School of Medicine, Tsinghua University, Beijing, 100084, China
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing, 100084, China
| | - Nan Wang
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing, 100084, China
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xiaoou Sun
- School of Medicine, Tsinghua University, Beijing, 100084, China
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing, 100084, China
| | - Linqi Zhang
- School of Medicine, Tsinghua University, Beijing, 100084, China
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing, 100084, China
- NexVac Research Center, Comprehensive AIDS Research Center, Center for Infectious Disease Research, Tsinghua University, Beijing, 100084, China
| | - Chuangye Yan
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing, 100084, China.
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
| | - Brian K Kobilka
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
| | - Xiangyu Liu
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing, 100084, China.
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Pharmaceutical Sciences, Tsinghua University, Beijing, 100084, China.
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Papay RS, Macdonald JD, Stauffer SR, Perez DM. Characterization of a novel positive allosteric modulator of the α 1A-Adrenergic receptor. CURRENT RESEARCH IN PHARMACOLOGY AND DRUG DISCOVERY 2022; 4:100142. [PMID: 36544813 PMCID: PMC9762201 DOI: 10.1016/j.crphar.2022.100142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/27/2022] [Accepted: 11/15/2022] [Indexed: 12/05/2022] Open
Abstract
α1-Adrenergic Receptors (ARs) are G-protein Coupled Receptors (GPCRs) that regulate the sympathetic nervous system via the binding and activation of norepinephrine (NE) and epinephrine (Epi). α1-ARs control various aspects of neurotransmission, cognition, cardiovascular functions as well as other organ systems. However, therapeutic drug development for these receptors, particularly agonists, has been stagnant due to unwanted effects on blood pressure regulation. We report the synthesis and characterization of the first positive allosteric modulator (PAM) for the α1-AR based upon the derivation of the α1A-AR selective imidazoline agonist, cirazoline. Compound 3 (Cmpd-3) binds the α1A-AR with high and low affinity sites (0.13pM; 54 nM) typical of GPCR agonists, and reverts to a single low affinity site of 100 nM upon the addition of GTP. Comparison of Cmpd-3 versus other orthosteric α1A-AR-selective imidazoline ligands reveal unique properties that are consistent with a type I PAM. Cmpd-3 is both conformationally and ligand-selective for the α1A-AR subtype. In competition binding studies, Cmpd-3 potentiates NE-binding at the α1A-AR only on the high affinity state of NE with no effect on the Epi-bound α1A-AR. Moreover, Cmpd-3 demonstrates signaling-bias and potentiates the NE-mediated cAMP response of the α1A-AR at nM concentrations with no effects on the NE-mediated inositol phosphate response. There are no effects of Cmpd-3 on the signaling at the α1B- or α1D-AR subtypes. Cmpd-3 displays characteristics of a pure PAM with no intrinsic agonist properties. Specific derivation of Cmpd-3 at the R1 ortho-position recapitulated PAM characteristics. Our results characterize the first PAM for the α1-AR and holds promise for a first-in-class therapeutic to treat various diseases without the side effect of increasing blood pressure intrinsic to classical orthosteric agonists.
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Affiliation(s)
- Robert S. Papay
- The Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH, 44195, USA
| | - Jonathan D. Macdonald
- Center for Therapeutics Discovery, Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH, 44195, USA
| | - Shaun R. Stauffer
- Center for Therapeutics Discovery, Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH, 44195, USA
| | - Dianne M. Perez
- The Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH, 44195, USA
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3
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Polymorphisms in common antihypertensive targets: Pharmacogenomic implications for the treatment of cardiovascular disease. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2022; 94:141-182. [PMID: 35659371 DOI: 10.1016/bs.apha.2022.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The idea of personalized medicine came to fruition with sequencing the human genome; however, aside from a few cases, the genetic revolution has yet to materialize. Cardiovascular diseases are the leading cause of death globally, and hypertension is a common prelude to nearly all cardiovascular diseases. Thus, hypertension is an ideal candidate disease to apply tenants of personalized medicine to lessen cardiovascular disease. Herein is a survey that visually depicts the polymorphisms in the top eight antihypertensive targets. Although there are numerous genome-wide association studies regarding cardiovascular disease, few studies look at the effects of receptor polymorphisms on drug treatment. With 17,000+ polymorphisms in the combined target proteins examined, it is expected that some of the clinical variability in the treatment of hypertension is due to polymorphisms in the drug targets. Recent advances in techniques and technology, such as high throughput examination of single mutations, structure prediction, computational power for modeling, and CRISPR models of point mutations, allow for a relatively rapid and comprehensive examination of the effects of known and future polymorphisms on drug affinity and effects. As hypertension is easy to measure and has a plethora of clinically viable ligands, hypertension makes an excellent disease to study pharmacogenomics in the lab and the clinic. If the promises of personalized medicine are to materialize, a concerted effort to examine the effects polymorphisms have on drugs is required. A clinician with the knowledge of a patient's genotype can then prescribe drugs that are optimal for treating that specific patient.
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da Silva SB, Feitosa SGD, de L Alves SM, Santos RCA, Dos Anjos JV, Araújo AV. A Concise and Useful Guide to Understand How Alpha1 Adrenoceptor Antagonists Work. Mini Rev Med Chem 2022; 22:2383-2405. [PMID: 35507746 DOI: 10.2174/1389557522666220504141949] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 02/23/2022] [Accepted: 03/16/2022] [Indexed: 11/22/2022]
Abstract
Adrenoceptors are the receptors for the catecholamines, adrenaline and noradrenaline. They are divided in α (α1 and α2) and β (β1, β2 and β3). α1-Adrenoceptors are subdivided in α1A, α1B and α1D. Most tissues express mixtures of α1-adrenoceptors subtypes, which appear to coexist in different densities and ratios, and in most cases their responses are probably due to the activation of more than one type. The three subtypes of α1-adrenoceptors are G-protein-coupled receptors (GPCR), specifically coupled to Gq/11. Additionally, the activation of these receptors may activate other signaling pathways or different components of these pathways, which leads to a great variety of possible cellular effects. The first clinically used α1 antagonist was Prazosin, for Systemic Arterial Hypertension (SAH). It was followed by its congeners, Terazosin and Doxazosin. Nowadays, there are many classes of α-adrenergic antagonists with different selectivity profiles. In addition to SAH, the α1-adrenoceptors are used for the treatment of Benign Prostatic Hyperplasia (BPH) and urolithiasis. This antagonism may be part of the mechanism of action of tricyclic antidepressants. Moreover, the activation of these receptors may lead to adverse effects such as orthostatic hypotension, similar to what happens with the antidepressants and with some antipsychotic. Structure-activity relationships can explain, in part, how antagonists work and how selective they can be for each one of the subtypes. However, it is necessary to develop new molecules which antagonize the α1-adrenoceptors or make chemical modifications in these molecules to improve the selectivity, pharmacokinetic profile and/or reduce the adverse effects of known drugs.
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Affiliation(s)
- Sidiane B da Silva
- Laboratório de Nutrição, Atividade Física e Plasticidade Fenotípica - Centro Acadêmico de Vitória - Universidade Federal de Pernambuco. R. Alto do Reservatório, s/n Bela Vista - Vitória de Santo Antão, PE, 50608-680, Brazil
| | - Sidney G D Feitosa
- Departamento de Química Fundamental - Universidade Federal de Pernambuco. Av. Jornalista Aníbal Fernandes, s/n, Cidade Universitária - Recife, PE, 50740-560, Brazil
| | - Silvia M de L Alves
- Laboratório de Nutrição, Atividade Física e Plasticidade Fenotípica - Centro Acadêmico de Vitória - Universidade Federal de Pernambuco. R. Alto do Reservatório, s/n Bela Vista - Vitória de Santo Antão, PE, 50608-680, Brazil
| | - Ruth C A Santos
- Laboratório de Nutrição, Atividade Física e Plasticidade Fenotípica - Centro Acadêmico de Vitória - Universidade Federal de Pernambuco. R. Alto do Reservatório, s/n Bela Vista - Vitória de Santo Antão, PE, 50608-680, Brazil
| | - Janaína V Dos Anjos
- Departamento de Química Fundamental - Universidade Federal de Pernambuco. Av. Jornalista Aníbal Fernandes, s/n, Cidade Universitária - Recife, PE, 50740-560, Brazil
| | - Alice V Araújo
- Núcleo de Saúde Pública, Centro Acadêmico de Vitória - Universidade Federal de Pernambuco R. Alto do Reservatório, s/n Bela Vista - Vitória de Santo Antão, PE, 50608-680, Brazil
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5
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Targeting Adrenergic Receptors in Metabolic Therapies for Heart Failure. Int J Mol Sci 2021; 22:ijms22115783. [PMID: 34071350 PMCID: PMC8198887 DOI: 10.3390/ijms22115783] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 05/20/2021] [Accepted: 05/22/2021] [Indexed: 12/14/2022] Open
Abstract
The heart has a reduced capacity to generate sufficient energy when failing, resulting in an energy-starved condition with diminished functions. Studies have identified numerous changes in metabolic pathways in the failing heart that result in reduced oxidation of both glucose and fatty acid substrates, defects in mitochondrial functions and oxidative phosphorylation, and inefficient substrate utilization for the ATP that is produced. Recent early-phase clinical studies indicate that inhibitors of fatty acid oxidation and antioxidants that target the mitochondria may improve heart function during failure by increasing compensatory glucose oxidation. Adrenergic receptors (α1 and β) are a key sympathetic nervous system regulator that controls cardiac function. β-AR blockers are an established treatment for heart failure and α1A-AR agonists have potential therapeutic benefit. Besides regulating inotropy and chronotropy, α1- and β-adrenergic receptors also regulate metabolic functions in the heart that underlie many cardiac benefits. This review will highlight recent studies that describe how adrenergic receptor-mediated metabolic pathways may be able to restore cardiac energetics to non-failing levels that may offer promising therapeutic strategies.
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6
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Perez DM. Current Developments on the Role of α 1-Adrenergic Receptors in Cognition, Cardioprotection, and Metabolism. Front Cell Dev Biol 2021; 9:652152. [PMID: 34113612 PMCID: PMC8185284 DOI: 10.3389/fcell.2021.652152] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 04/29/2021] [Indexed: 12/13/2022] Open
Abstract
The α1-adrenergic receptors (ARs) are G-protein coupled receptors that bind the endogenous catecholamines, norepinephrine, and epinephrine. They play a key role in the regulation of the sympathetic nervous system along with β and α2-AR family members. While all of the adrenergic receptors bind with similar affinity to the catecholamines, they can regulate different physiologies and pathophysiologies in the body because they couple to different G-proteins and signal transduction pathways, commonly in opposition to one another. While α1-AR subtypes (α1A, α1B, α1C) have long been known to be primary regulators of vascular smooth muscle contraction, blood pressure, and cardiac hypertrophy, their role in neurotransmission, improving cognition, protecting the heart during ischemia and failure, and regulating whole body and organ metabolism are not well known and are more recent developments. These advancements have been made possible through the development of transgenic and knockout mouse models and more selective ligands to advance their research. Here, we will review the recent literature to provide new insights into these physiological functions and possible use as a therapeutic target.
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Affiliation(s)
- Dianne M Perez
- The Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, OH, United States
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7
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Qu L, Zhou Q, Xu Y, Guo Y, Chen X, Yao D, Han GW, Liu ZJ, Stevens RC, Zhong G, Wu D, Zhao S. Structural Basis of the Diversity of Adrenergic Receptors. Cell Rep 2020; 29:2929-2935.e4. [PMID: 31801060 DOI: 10.1016/j.celrep.2019.10.088] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 09/23/2019] [Accepted: 10/22/2019] [Indexed: 11/25/2022] Open
Abstract
Adrenergic receptors are highly homologous while at the same time display a wide diversity of ligand and G-protein binding, and understanding this diversity is key for designing selective or biased drugs for them. Here, we determine two crystal structures of the α2A adrenergic receptor (α2AAR) in complex with a partial agonist and an antagonist. Key non-conserved residues from the ligand-binding pocket (Phe7.39 and Tyr6.55) to G-protein coupling region (Ile34.51 and Lys34.56) are discovered to play a key role in the interplay between partial agonism and biased signaling of α2AAR, which provides insights into the diversity of ligand binding and G-protein coupling preference of adrenergic receptors and lays the foundation for the discovery of next-generation drugs targeting these receptors.
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Affiliation(s)
- Lu Qu
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China; National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qingtong Zhou
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China
| | - Yueming Xu
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China
| | - Yu Guo
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Xiaoyu Chen
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Deqiang Yao
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China
| | - Gye Won Han
- Departments of Biological Sciences and Chemistry, Bridge Institute, University of Southern California, Los Angeles, CA 90089, USA
| | - Zhi-Jie Liu
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Raymond C Stevens
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China; Departments of Biological Sciences and Chemistry, Bridge Institute, University of Southern California, Los Angeles, CA 90089, USA
| | - Guisheng Zhong
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.
| | - Dong Wu
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China.
| | - Suwen Zhao
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.
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8
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Vass M, Podlewska S, de Esch IJP, Bojarski AJ, Leurs R, Kooistra AJ, de Graaf C. Aminergic GPCR-Ligand Interactions: A Chemical and Structural Map of Receptor Mutation Data. J Med Chem 2018; 62:3784-3839. [PMID: 30351004 DOI: 10.1021/acs.jmedchem.8b00836] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The aminergic family of G protein-coupled receptors (GPCRs) plays an important role in various diseases and represents a major drug discovery target class. Structure determination of all major aminergic subfamilies has enabled structure-based ligand design for these receptors. Site-directed mutagenesis data provides an invaluable complementary source of information for elucidating the structural determinants of binding of different ligand chemotypes. The current study provides a comparative analysis of 6692 mutation data points on 34 aminergic GPCR subtypes, covering the chemical space of 540 unique ligands from mutagenesis experiments and information from experimentally determined structures of 52 distinct aminergic receptor-ligand complexes. The integrated analysis enables detailed investigation of structural receptor-ligand interactions and assessment of the transferability of combined binding mode and mutation data across ligand chemotypes and receptor subtypes. An overview is provided of the possibilities and limitations of using mutation data to guide the design of novel aminergic receptor ligands.
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Affiliation(s)
- Márton Vass
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS) , VU University Amsterdam , 1081HZ Amsterdam , The Netherlands
| | - Sabina Podlewska
- Department of Medicinal Chemistry, Institute of Pharmacology , Polish Academy of Sciences , Smętna 12 , PL31-343 Kraków , Poland
| | - Iwan J P de Esch
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS) , VU University Amsterdam , 1081HZ Amsterdam , The Netherlands
| | - Andrzej J Bojarski
- Department of Medicinal Chemistry, Institute of Pharmacology , Polish Academy of Sciences , Smętna 12 , PL31-343 Kraków , Poland
| | - Rob Leurs
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS) , VU University Amsterdam , 1081HZ Amsterdam , The Netherlands
| | - Albert J Kooistra
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS) , VU University Amsterdam , 1081HZ Amsterdam , The Netherlands.,Department of Drug Design and Pharmacology , University of Copenhagen , Universitetsparken 2 , 2100 Copenhagen , Denmark
| | - Chris de Graaf
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS) , VU University Amsterdam , 1081HZ Amsterdam , The Netherlands.,Sosei Heptares , Steinmetz Building, Granta Park, Great Abington , Cambridge CB21 6DG , U.K
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9
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Yong KJ, Vaid TM, Shilling PJ, Wu FJ, Williams LM, Deluigi M, Plückthun A, Bathgate RAD, Gooley PR, Scott DJ. Determinants of Ligand Subtype-Selectivity at α 1A-Adrenoceptor Revealed Using Saturation Transfer Difference (STD) NMR. ACS Chem Biol 2018. [PMID: 29537256 DOI: 10.1021/acschembio.8b00191] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
α1A- and α1B-adrenoceptors (α1A-AR and α1B-AR) are closely related G protein-coupled receptors (GPCRs) that modulate the cardiovascular and nervous systems in response to binding epinephrine and norepinephrine. The GPCR gene superfamily is made up of numerous subfamilies that, like α1A-AR and α1B-AR, are activated by the same endogenous agonists but may modulate different physiological processes. A major challenge in GPCR research and drug discovery is determining how compounds interact with receptors at the molecular level, especially to assist in the optimization of drug leads. Nuclear magnetic resonance spectroscopy (NMR) can provide great insight into ligand-binding epitopes, modes, and kinetics. Ideally, ligand-based NMR methods require purified, well-behaved protein samples. The instability of GPCRs upon purification in detergents, however, makes the application of NMR to study ligand binding challenging. Here, stabilized α1A-AR and α1B-AR variants were engineered using Cellular High-throughput Encapsulation, Solubilization, and Screening (CHESS), allowing the analysis of ligand binding with Saturation Transfer Difference NMR (STD NMR). STD NMR was used to map the binding epitopes of epinephrine and A-61603 to both receptors, revealing the molecular determinants for the selectivity of A-61603 for α1A-AR over α1B-AR. The use of stabilized GPCRs for ligand-observed NMR experiments will lead to a deeper understanding of binding processes and assist structure-based drug design.
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Affiliation(s)
- Kelvin J. Yong
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, 30 Royal Parade, Parkville, Victoria 3052, Australia
- The Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Tasneem M. Vaid
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, 30 Royal Parade, Parkville, Victoria 3052, Australia
- The Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
- The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Patrick J. Shilling
- The Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
- The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Feng-Jie Wu
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, 30 Royal Parade, Parkville, Victoria 3052, Australia
- The Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
- The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Lisa M. Williams
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, 30 Royal Parade, Parkville, Victoria 3052, Australia
| | - Mattia Deluigi
- Department of Biochemistry, University of Zurich, 8057 Zurich, Switzerland
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich, 8057 Zurich, Switzerland
| | - Ross A. D. Bathgate
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, 30 Royal Parade, Parkville, Victoria 3052, Australia
- The Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Paul R. Gooley
- The Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
- The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Daniel J. Scott
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, 30 Royal Parade, Parkville, Victoria 3052, Australia
- The Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
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10
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Template selection and refinement considerations for modelling aminergic GPCR-ligand complexes. J Mol Graph Model 2017; 76:488-503. [PMID: 28818718 DOI: 10.1016/j.jmgm.2017.07.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 07/21/2017] [Accepted: 07/25/2017] [Indexed: 11/24/2022]
Abstract
G protein-coupled receptors (GPCRs) are important targets for development of drugs for the treatment of many diseases. However, crystal structures are available for only a small fraction of these membrane bound proteins. Accurate homology models will provide opportunities for effective drug design targeting GPCRs. Recently, several serotonin receptor crystal structures were solved and needed to be evaluated as potential templates. In the first part of this work different measures of similarity in template selection were explored and methods for homology modelling, docking and refinement of aminergic GPCR-ligand complexes were developed and evaluated by comparing models of the D3-R/eticlopride complex with the crystal structure. Homology models of the three α1 adrenergic receptor subtypes and of a serotonin receptor subtype were then constructed using these methods These models were evaluated by docking a range of antagonists into them.
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11
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Zhao XF, Wang J, Liu GX, Fan TP, Zhang YJ, Yu J, Wang SX, Li ZJ, Zhang YY, Zheng XH. Binding mechanism of nine N-phenylpiperazine derivatives and α1A-adrenoceptor using site-directed molecular docking and high performance affinity chromatography. RSC Adv 2015. [DOI: 10.1039/c5ra10812h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Investigating the binding mechanism of α1A-adrenoceptor and its specific ligands by affinity chromatography.
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12
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Maïga A, Dupont M, Blanchet G, Marcon E, Gilquin B, Servent D, Gilles N. Molecular exploration of the α1A-adrenoceptor orthosteric site: Binding site definition for epinephrine, HEAT and prazosin. FEBS Lett 2014; 588:4613-9. [DOI: 10.1016/j.febslet.2014.10.033] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 10/10/2014] [Accepted: 10/27/2014] [Indexed: 11/24/2022]
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13
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Longstanding complex regional pain syndrome is associated with activating autoantibodies against alpha-1a adrenoceptors. Pain 2014; 155:2408-17. [DOI: 10.1016/j.pain.2014.09.022] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 09/09/2014] [Accepted: 09/16/2014] [Indexed: 11/22/2022]
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Ragnarsson L, Andersson Å, Thomas WG, Lewis RJ. Extracellular Surface Residues of the α1B-Adrenoceptor Critical for G Protein–Coupled Receptor Function. Mol Pharmacol 2014; 87:121-9. [DOI: 10.1124/mol.114.094557] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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15
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Campbell AP, MacDougall IJA, Griffith R, Finch AM. An aspartate in the second extracellular loop of the α(1B) adrenoceptor regulates agonist binding. Eur J Pharmacol 2014; 733:90-6. [PMID: 24690260 DOI: 10.1016/j.ejphar.2014.03.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 03/20/2014] [Accepted: 03/24/2014] [Indexed: 11/30/2022]
Abstract
The extracellular loops of the adrenoceptors present a potential therapeutic target in the design of highly selective adrenergic drugs. These regions are less conserved than the orthosteric binding site but have to date not been implicated in activation of adrenoceptors. A previously generated homology model identified an extracellular residue, D191, as a potential regulator of agonist binding. We have generated mutants of the α1B adrenoceptor replacing the charged aspartate, D191, as well as a potential interaction partner, K331, with uncharged alanines to observe effects on ligand binding and receptor activation. Significant 4-6 fold reductions in affinity for the endogenous agonists, epinephrine and norepinephrine were observed for receptors with the D191A mutation in the second extracellular loop. While changes in EC50 were observed, operational analysis yielded no apparent change in receptor activation. Based on these findings, we suggest that D191, in the second extracellular loop of the α1B adrenoceptor, acts as a 'point of first contact' for the receptor's endogenous agonists. Implication of the non-conserved extracellular regions of the receptor in agonist binding makes it a potential target for the design of highly selective drugs.
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Affiliation(s)
- Adrian P Campbell
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Kensington, NSW 2052, Australia
| | - Iain J A MacDougall
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
| | - Renate Griffith
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Kensington, NSW 2052, Australia
| | - Angela M Finch
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Kensington, NSW 2052, Australia.
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16
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Maïga A, Merlin J, Marcon E, Rouget C, Larregola M, Gilquin B, Fruchart-Gaillard C, Lajeunesse E, Marchetti C, Lorphelin A, Bellanger L, Summers RJ, Hutchinson DS, Evans BA, Servent D, Gilles N. Orthosteric binding of ρ-Da1a, a natural peptide of snake venom interacting selectively with the α1A-adrenoceptor. PLoS One 2013; 8:e68841. [PMID: 23935897 PMCID: PMC3723878 DOI: 10.1371/journal.pone.0068841] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 06/01/2013] [Indexed: 01/02/2023] Open
Abstract
ρ-Da1a is a three-finger fold toxin from green mamba venom that is highly selective for the α1A-adrenoceptor. This toxin has atypical pharmacological properties, including incomplete inhibition of 3H-prazosin or 125I-HEAT binding and insurmountable antagonist action. We aimed to clarify its mode of action at the α1A-adrenoceptor. The affinity (pKi 9.26) and selectivity of ρ-Da1a for the α1A-adrenoceptor were confirmed by comparing binding to human adrenoceptors expressed in eukaryotic cells. Equilibrium and kinetic binding experiments were used to demonstrate that ρ-Da1a, prazosin and HEAT compete at the α1A-adrenoceptor. ρ-Da1a did not affect the dissociation kinetics of 3H-prazosin or 125I-HEAT, and the IC50 of ρ-Da1a, determined by competition experiments, increased linearly with the concentration of radioligands used, while the residual binding by ρ-Da1a remained stable. The effect of ρ-Da1a on agonist-stimulated Ca2+ release was insurmountable in the presence of phenethylamine- or imidazoline-type agonists. Ten mutations in the orthosteric binding pocket of the α1A-adrenoceptor were evaluated for alterations in ρ-Da1a affinity. The D1063.32A and the S1885.42A/S1925.46A receptor mutations reduced toxin affinity moderately (6 and 7.6 times, respectively), while the F862.64A, F2886.51A and F3127.39A mutations diminished it dramatically by 18- to 93-fold. In addition, residue F862.64 was identified as a key interaction point for 125I-HEAT, as the variant F862.64A induced a 23-fold reduction in HEAT affinity. Unlike the M1 muscarinic acetylcholine receptor toxin MT7, ρ-Da1a interacts with the human α1A-adrenoceptor orthosteric pocket and shares receptor interaction points with antagonist (F862.64, F2886.51 and F3127.39) and agonist (F2886.51 and F3127.39) ligands. Its selectivity for the α1A-adrenoceptor may result, at least partly, from its interaction with the residue F862.64, which appears to be important also for HEAT binding.
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Affiliation(s)
- Arhamatoulaye Maïga
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
| | - Jon Merlin
- Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Elodie Marcon
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
| | - Céline Rouget
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
| | - Maud Larregola
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
| | - Bernard Gilquin
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service de Bioénergétique, Biologie Structurale et Mécanismes, Gif sur Yvette, France
| | - Carole Fruchart-Gaillard
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
| | - Evelyne Lajeunesse
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
| | - Charles Marchetti
- Commissariat à l'énergie atomique et aux énergies alternatives, iBEB, Service de Biochimie et Toxicologie Nucléaire, Bagnols-sur-Cèze Cedex, France
| | - Alain Lorphelin
- Commissariat à l'énergie atomique et aux énergies alternatives, iBEB, Service de Biochimie et Toxicologie Nucléaire, Bagnols-sur-Cèze Cedex, France
| | - Laurent Bellanger
- Commissariat à l'énergie atomique et aux énergies alternatives, iBEB, Service de Biochimie et Toxicologie Nucléaire, Bagnols-sur-Cèze Cedex, France
| | - Roger J. Summers
- Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Dana S. Hutchinson
- Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Bronwyn A. Evans
- Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Denis Servent
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
| | - Nicolas Gilles
- Commissariat à l'énergie atomique et aux énergies alternatives, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines, Gif sur Yvette, France
- * E-mail:
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17
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Chen J, Murad AK, Wakelin LPG, Denny WA, Griffith R, Finch AM. α₁-Adrenoceptor and serotonin 5-HT(1A) receptor affinity of homobivalent 4-aminoquinoline compounds: an investigation of the effect of linker length. Biochem Pharmacol 2013; 85:1534-41. [PMID: 23524075 DOI: 10.1016/j.bcp.2013.03.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 03/12/2013] [Accepted: 03/13/2013] [Indexed: 11/18/2022]
Abstract
α₁-adrenoceptor (α₁-AR) subtype-selective ligands lacking off-target affinity for the 5-HT(1A) receptor (5-HT(1A)-R) will provide therapeutic benefits in the treatment of urogenital conditions such as benign prostatic hyperplasia. In this study we determined the affinity of 4-aminoquinoline and eleven homobivalent 4-aminoquinoline ligands (diquinolines) with alkane linkers of 2-12 atoms (C2-C12) for α(1A), α(1B) and α(1D)-ARs and the 5-HT(1A)-R. These ligands are α(1A)-AR antagonists with nanomolar affinity for α(1A) and α(1B)-ARs. They display linker-length dependent selectivity for α(1A/B)-ARs over α(1D)-AR and the 5-HT(1A)-R. The C2 diquinoline has the highest affinity for α1A-AR (pKi 7.60±0.26) and greater than 30-fold and 600-fold selectivity for α(1A)-AR over α(1D)-AR and 5-HT(1A)-R respectively. A decrease in affinity for α₁-ARs is observed as the linker length increases, reaching a nadir at 5 (α(1A/1B)-ARs) or 6 (α(1D)-AR) atoms; after which affinity increases as the linker is lengthened, peaking at 9 (α(1A/1B/1D)-ARs) or 8 (5-HT(1A)-R) atoms. Docking studies suggest that 4-aminoquinoline and C2 bind within the orthosteric binding site, while for C9 one end is situated within the orthosteric binding pocket, while the other 4-aminoquinoline moiety interacts with the extracellular surface. The limited α(1D)-AR and 5-HT(1A)-R affinity of these compounds makes them promising leads for future drug development of α(1A)-AR selective ligands without α(1D)-AR and the 5-HT(1A)-R off-target activity.
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Affiliation(s)
- Junli Chen
- Department of Pharmacology, School of Medical Sciences, UNSW, Sydney, NSW 2052, Australia
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18
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Ragnarsson L, Wang CIA, Andersson Å, Fajarningsih D, Monks T, Brust A, Rosengren KJ, Lewis RJ. Conopeptide ρ-TIA defines a new allosteric site on the extracellular surface of the α1B-adrenoceptor. J Biol Chem 2012. [PMID: 23184947 DOI: 10.1074/jbc.m112.430785] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The G protein-coupled receptor (GPCR) superfamily is an important drug target that includes over 1000 membrane receptors that functionally couple extracellular stimuli to intracellular effectors. Despite the potential of extracellular surface (ECS) residues in GPCRs to interact with subtype-specific allosteric modulators, few ECS pharmacophores for class A receptors have been identified. Using the turkey β(1)-adrenergic receptor crystal structure, we modeled the α(1B)-adrenoceptor (α(1B)-AR) to help identify the allosteric site for ρ-conopeptide TIA, an inverse agonist at this receptor. Combining mutational radioligand binding and inositol 1-phosphate signaling studies, together with molecular docking simulations using a refined NMR structure of ρ-TIA, we identified 14 residues on the ECS of the α(1B)-AR that influenced ρ-TIA binding. Double mutant cycle analysis and docking confirmed that ρ-TIA binding was dominated by a salt bridge and cation-π between Arg-4-ρ-TIA and Asp-327 and Phe-330, respectively, and a T-stacking-π interaction between Trp-3-ρ-TIA and Phe-330. Water-bridging hydrogen bonds between Asn-2-ρ-TIA and Val-197, Trp-3-ρ-TIA and Ser-318, and the positively charged N terminus and Glu-186, were also identified. These interactions reveal that peptide binding to the ECS on transmembrane helix 6 (TMH6) and TMH7 at the base of extracellular loop 3 (ECL3) is sufficient to allosterically inhibit agonist signaling at a GPCR. The ligand-accessible ECS residues identified provide the first view of an allosteric inhibitor pharmacophore for α(1)-adrenoceptors and mechanistic insight and a new set of structural constraints for the design of allosteric antagonists at related GPCRs.
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Affiliation(s)
- Lotten Ragnarsson
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia
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19
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Fumagalli L, Pallavicini M, Budriesi R, Gobbi M, Straniero V, Zagami M, Chiodini G, Bolchi C, Chiarini A, Micucci M, Valoti E. Affinity and activity profiling of unichiral 8-substituted 1,4-benzodioxane analogues of WB4101 reveals a potent and selective α1B-adrenoceptor antagonist. Eur J Med Chem 2012; 58:184-91. [PMID: 23124215 DOI: 10.1016/j.ejmech.2012.09.049] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 09/27/2012] [Accepted: 09/28/2012] [Indexed: 11/28/2022]
Abstract
Unichiral 8-substituted analogues of 2-[(2-(2,6-dimethoxyphenoxy)ethyl)aminomethyl]-1,4-benzodioxane (WB4101) were synthesized and tested for binding affinity at cloned human α(1a)-, α(1b)-and α(1d)-adrenoreceptor (α(1a)-, α(1b)-and α(1d)-AR) and at native rat 5-HT(1A) receptor and for antagonist affinity at α(1A)-, α(1B)-and α(1D)-AR and at α(2A/D)-AR. Among the selected 8-substituents, namely fluorine, chlorine, methoxyl and hydroxyl, only the last caused significant decrease of α(1) binding affinity in comparison with the lead compound. Functional tests on the S isomers confirmed the detrimental effect of OH positioned in proximity to benzodioxane O(1). For the other three substituents (F, Cl, OMe), the α(1A) and the α(1D) antagonist affinities were generally lower than the α(1a) and α(1d) binding affinities, but not the α(1B) antagonist affinity, which was similar and sensibly higher compared to α(1b) binding affinity in the case of F and OMe respectively. This trend confers significant α(1B)-AR selectivity, in particular, to the 8-methoxy analogue of (S)-WB4101, a new potent (pA(2) 9.58) α(1B)-AR antagonist. The S enantiomers of all the tested compounds were proved to act as α(1)-AR inverse agonists in a vascular model.
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Affiliation(s)
- Laura Fumagalli
- Dipartimento di Scienze Farmaceutiche, Università di Milano, via Mangiagalli 25, I-20133 Milano, Italy
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20
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McCune DF, Gaivin RJ, Rorabaugh BR, Perez DM. Bulk is a Determinant of Oxymetazoline Affinity for the α1A-Adrenergic Receptor. ACTA ACUST UNITED AC 2011. [DOI: 10.3109/10606820490514923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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21
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Witt KM, Bockman CS, Dang HK, Gruber DD, Wangemann P, Scofield MA. Molecular and pharmacological characteristics of the gerbil α(1a)-adrenergic receptor. Hear Res 2011; 283:144-50. [PMID: 22101021 DOI: 10.1016/j.heares.2011.11.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Revised: 10/25/2011] [Accepted: 11/01/2011] [Indexed: 11/27/2022]
Abstract
The spiral modiolar artery supplies blood and essential nutrients to the cochlea. Our previous functional study indicates the α(1A)-adrenergic receptor subtype mediates vasoconstriction of the gerbil spiral modiolar artery. Although the gerbil cochlea is often used as a model in hearing research, the molecular and pharmacological characteristics of the cloned gerbil α(1a)-adrenergic receptor have not been determined. Thus we cloned, expressed and characterized the gerbil α(1a)-adrenergic receptor and then compared its molecular and pharmacological properties to those of other mammalian α(1a)-adrenergic receptors. The cDNA clone contained 1404 nucleotides, which encoded a 467 amino acid peptide with a deduced sequence having 96.8, 96.4 and 91.6% identity to rat, mouse and human α(1a)-receptors, respectively. We transiently transfected the α(1a)-adrenergic receptor into COS-1 cells and determined its pharmacological characteristics by [(3)H]prazosin binding. Unlabeled prazosin had a K(i) of 0.89±0.1nM. The α(1A)-adrenergic receptor-selective antagonists, 5-methylurapidil and WB-4101, bound with high affinity and had K(i) values of 4.9±1 and 1.0±0.1nM, respectively. BMY-7378, an α(1D)-adrenergic receptor-selective antagonist, bound with low affinity (260±60nM). The 91.6% amino acid sequence identity and K(i)s of the cloned gerbil α(1a)-adrenergic receptor are similar to those of the human α(1a)-adrenergic receptor clone. These results show that the gerbil α(1a)-adrenergic receptor is representative of the human α(1a)-adrenergic receptor, lending validity to the use of the gerbil spiral modiolar artery as a model in studies of vascular disorders of the cochlea.
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Affiliation(s)
- Kelly M Witt
- Department of Pharmacology, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA.
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22
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Discovery of LASSBio-772, a 1,3-benzodioxole N-phenylpiperazine derivative with potent alpha 1A/D-adrenergic receptor blocking properties. Eur J Med Chem 2011; 46:3000-12. [PMID: 21549456 DOI: 10.1016/j.ejmech.2011.04.032] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2010] [Revised: 04/04/2011] [Accepted: 04/12/2011] [Indexed: 11/21/2022]
Abstract
We described herein the discovery of 1-(2-(benzo[d] [1,3]dioxol-6-yl)ethyl)-4-(2-methoxyphenyl) piperazine (LASSBio-772), as a novel potent and selective alpha 1A/1D adrenoceptor (AR) antagonist selected after screening of functionalized N-phenylpiperazine derivatives in phenylephrine-induced vasoconstriction of rabbit aorta rings. The affinity of LASSBio-772 for alpha 1A and alpha 1B AR subtypes was determined through displacement of [(3)H]prazosin binding. We obtained Ki values of 0.14 nM for the alpha 1A-AR, similar to that displayed by tamsulosin (K(i) = 0.13 nM) and 5.55 nM for the alpha 1B-AR, representing a 40-fold higher affinity for alpha 1A-AR. LASSBio-772 also presented high affinity (K(B) = 0.025 nM) for the alpha 1D-AR subtype in the functional rat aorta assay, showing to be equipotent to tamsulosin (K(B) = 0.017 nM).
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23
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Synthesis and α1-adrenoceptor antagonist activity of tamsulosin analogues. Eur J Med Chem 2010; 45:5800-7. [DOI: 10.1016/j.ejmech.2010.09.042] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 09/16/2010] [Accepted: 09/17/2010] [Indexed: 11/21/2022]
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24
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Carrieri A, Piergentili A, Bello FD, Giannella M, Pigini M, Leonardi A, Fanelli F, Quaglia W. Structure–activity relationships in 1,4-benzodioxan-related compounds. 10. Novel α1-adrenoreceptor antagonists related to openphendioxan: Synthesis, biological evaluation, and α1d computational study. Bioorg Med Chem 2010; 18:7065-77. [DOI: 10.1016/j.bmc.2010.08.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 07/28/2010] [Accepted: 08/02/2010] [Indexed: 01/03/2023]
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25
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Giorgioni G, Ambrosini D, Vesprini C, Hudson A, Nasuti C, Di Stefano A, Sozio P, Ciampi O, Costa B, Martini C, Carrieri A, Carbonara G, Enzensperger C, Pigini M. Novel imidazoline compounds as partial or full agonists of D2-like dopamine receptors inspired by I2-imidazoline binding sites ligand 2-BFI. Bioorg Med Chem 2010; 18:7085-91. [PMID: 20801048 DOI: 10.1016/j.bmc.2010.08.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Revised: 07/26/2010] [Accepted: 08/02/2010] [Indexed: 11/17/2022]
Abstract
Based on the well known biological versatility of the imidazoline nucleus, we prepared the novel derivatives 3a-k inspired by 2-BFI scaffold to assess imidazoline molecules as D(2)-like dopamine receptor ligands. Conservative chemical modifications of the lead structure, such as the introduction of an hydroxy group in the aromatic ring alone or associated with N-benzyl substitution, provided partial (3f) or nearly full (3e and 3h) agonists, all endowed with D(2)-like potency comparable to that of dopamine.
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Affiliation(s)
- Gianfabio Giorgioni
- Scuola di Scienze del Farmaco e dei Prodotti della Salute, Università degli Studi di Camerino, via Sant'Agostino 1, 62032 Camerino, Italy.
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26
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Wakimoto T, Nitta M, Kasahara K, Chiba T, Yiping Y, Tsuji K, Kan T, Nukaya H, Ishiguro M, Koike M, Yokoo Y, Suwa Y. Structure–activity relationship study on α1 adrenergic receptor antagonists from beer. Bioorg Med Chem Lett 2009; 19:5905-8. [DOI: 10.1016/j.bmcl.2009.08.068] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2009] [Revised: 08/18/2009] [Accepted: 08/19/2009] [Indexed: 10/20/2022]
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27
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Huber T, Menon S, Sakmar TP. Structural basis for ligand binding and specificity in adrenergic receptors: implications for GPCR-targeted drug discovery. Biochemistry 2008; 47:11013-23. [PMID: 18821775 DOI: 10.1021/bi800891r] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Crystal structures of engineered human beta 2-adrenergic receptors (ARs) in complex with an inverse agonist ligand, carazolol, provide three-dimensional snapshots of the disposition of seven transmembrane helices and the ligand-binding site of an important G protein-coupled receptor (GPCR). As expected, beta 2-AR shares substantial structural similarities with rhodopsin, the dim-light photoreceptor of the rod cell. However, although carazolol and the 11- cis-retinylidene moiety of rhodopsin are situated in the same general binding pocket, the second extracellular (E2) loop structures are quite distinct. E2 in rhodopsin shows beta-sheet structure and forms part of the chromophore-binding site. In the beta 2-AR, E2 is alpha-helical and seems to be distinct from the receptor's active site, allowing a potential entry pathway for diffusible ligands. The structures, together with extensive structure-activity relationship (SAR) data from earlier studies, provide insight about possible structural determinants of ligand specificity and how the binding of agonist ligands might alter receptor conformation. We review key features of the new beta 2-AR structures in the context of recent complementary work on the conformational dynamics of GPCRs. We also report 600 ns molecular dynamics simulations that quantified beta 2-AR receptor mobility in a membrane bilayer environment and show how the binding of an agonist ligand, adrenaline (epinephrine), causes conformational changes to the ligand-binding pocket and neighboring helices.
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Affiliation(s)
- Thomas Huber
- Laboratory of Molecular Biology and Biochemistry, The Rockefeller University, 1230 York Avenue, New York, New York 10065, USA.
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28
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Li M, Fang H, Du L, Xia L, Wang B. Computational studies of the binding site of alpha1A-adrenoceptor antagonists. J Mol Model 2008; 14:957-66. [PMID: 18626669 DOI: 10.1007/s00894-008-0342-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Accepted: 06/18/2008] [Indexed: 11/29/2022]
Abstract
Aimed at achieving a good understanding of the 3-dimensional structures of human alpha1A-adrenoceptor (alpha1A-AR), we have successfully developed its homology model based on the crystal structure of beta2-AR. Subsequent structural refinements were performed to mimic the receptor's natural membrane environment by using molecular mechanics (MM) and molecular dynamics (MD) simulations in the GBSW implicit membrane model. Through molecular docking and further simulations, possible binding modes of subtype-selective alpha1A-AR antagonists, Silodosin, RWJ-69736 and (+)SNAP-7915, were examined. Results of the modeling and docking studies are qualitatively consistent with available experimental data from mutagenesis studies. The homology model built should be very useful for designing more potent subtype-selective alpha1A-AR antagonists and for guiding further mutagenesis studies.
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Affiliation(s)
- Minyong Li
- Department of Chemistry and Center for Biotechnology and Drug Design, Georgia State University, Atlanta, GA 30302, USA.
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29
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Ahmed M, Hossain M, Bhuiyan MA, Ishiguro M, Tanaka T, Muramatsu I, Nagatomo T. Mutational Analysis of the .ALPHA.1a-Adrenergic Receptor Binding Pocket of Antagonists by Radioligand Binding Assay. Biol Pharm Bull 2008; 31:598-601. [DOI: 10.1248/bpb.31.598] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | - Murad Hossain
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Niigata University of Pharmacy and Applied Life Sciences
| | - Mohiuddin Ahmed Bhuiyan
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Niigata University of Pharmacy and Applied Life Sciences
| | - Masaji Ishiguro
- Department of Chemical Biology, Faculty of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences
| | - Takashi Tanaka
- Division of Pharmacology, Department of Biochemistry and Bioinformative Sciences, School of Medicine, University of Fukui
| | - Ikunobu Muramatsu
- Division of Pharmacology, Department of Biochemistry and Bioinformative Sciences, School of Medicine, University of Fukui
| | - Takafumi Nagatomo
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Niigata University of Pharmacy and Applied Life Sciences
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30
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Nagaoka Y, Ahmed M, Hossain M, Bhuiyan MA, Ishiguro M, Nakamura T, Watanabe M, Nagatomo T. Amino Acids of the Human α1d-Adrenergic Receptor Involved in Antagonist Binding. J Pharmacol Sci 2008; 106:114-20. [DOI: 10.1254/jphs.fp0071412] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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31
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Chen X, Perry SF, Aris-Brosou S, Selva C, Moon TW. Characterization and functional divergence of the alpha 1-adrenoceptor gene family: insights from rainbow trout (Oncorhynchus mykiss). Physiol Genomics 2007; 32:142-53. [PMID: 17940201 DOI: 10.1152/physiolgenomics.00258.2006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Presently, three alpha(1)-adrenoceptor (AR) types are recognized in vertebrates: alpha(1A)-, alpha(1B)-, and alpha(1D)-ARs. These alpha(1)-subtypes have distinct pharmacology and molecular profiles, play crucial roles in metabolic and vascular control, and are the targets for numerous pharmaceuticals, especially those affecting blood pressure and vascular resistance. To better understand the functional divergence within the alpha(1)-AR gene family, we sequenced these alpha(1)-AR paralogs in the rainbow trout and performed an extensive phylogenetic analysis. We show that these AR genes evolved by duplication events just before the origin of the jawed vertebrates. Our computational analyses suggest that the differences between the three alpha(1)-AR subtypes may affect their tissue specificity, ligand specificity, and possibly signal transduction processes and desensitization. We also show that, within each subtype, differences exist between fish and mammalian receptors, both at the transcriptional and at the physiological level. These differences, however, suggest that the role of alpha(1)-ARs in fish is more complex than previously thought. Our integrated analysis of the alpha(1)-AR gene family suggests that these receptors evolved these distinct features very early within vertebrates.
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Affiliation(s)
- Xi Chen
- Department of Biology and Centre for Advanced Research in Environmental Genomics, University of Ottawa, Ottawa, Ontario, Canada
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32
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Asher WB, Hoskins SN, Slasor LA, Morris DH, Cook EM, Bautista DL. Two model system of the alpha1A-adrenoceptor docked with selected ligands. J Chem Inf Model 2007; 47:1906-12. [PMID: 17715910 DOI: 10.1021/ci700026v] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study, we have developed a two model system to mimic the active and inactive states of a G-protein coupled receptor specifically the alpha1A adrenergic receptor. We have docked two agonists, epinephrine (phenylamine type) and oxymetazoline (imidazoline type), as well as two antagonists, prazosin and 5-methylurapidil, into two alpha1A receptor models, active and inactive. The best docking complexes for both agonists had hydrophilic interactions with D106, while neither antagonist did. Prazosin and oxymetazoline had hydrophobic interactions with F308 and F312. We predict from our study that the active state is stabilized by the interaction of F193 with I114, L197, V278, F281, and V282. The active state is further stabilized by the interaction of F312 with L75, V79, and L80. We also predict that the inactive state of the receptor is stabilized by the interaction of F312 with W102, F288, and M292.
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Affiliation(s)
- Wesley B Asher
- Chemistry Department, Eastern Kentucky University, 521 Lancaster Avenue, Richmond, Kentucky 40475, USA
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33
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Pallavicini M, Budriesi R, Fumagalli L, Ioan P, Chiarini A, Bolchi C, Ugenti MP, Colleoni S, Gobbi M, Valoti E. WB4101-Related Compounds: New, Subtype-Selective α1-Adrenoreceptor Antagonists (or Inverse Agonists?). J Med Chem 2006; 49:7140-9. [PMID: 17125266 DOI: 10.1021/jm060358r] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Our previous structure-affinity relationship study had considered the enantiomers of the naphthodioxane, tetrahydronaphthodioxane, and 2-methoxy-1-naphthoxy analogues (compounds 1, 3, and 2, respectively) of 2-(2,6-dimethoxyphenoxyethylaminomethyl)-1,4-benzodioxane, the well-known alpha1-adrenoceptor (alpha1-AR) antagonist WB4101, showing that such modifications significantly modulate the affinity and selectivity profile for alpha1-AR subtypes and 5-HT1A receptor. Here, we extend investigations to antagonist activity enclosing new enantiomeric pairs, namely those of the methoxytetrahydronaphthoxy and methoxybiphenyloxy WB4101 analogues (4 and 5-7, respectively) and of a double-modified WB4101 derivative (8) resulting from hybridization between 2 and 3. We found that (S)-2 is a very potent (pA2 10.68) and moderately selective alpha1D-AR antagonist and the hybrid (S)-8 is a potent (pA2 7.98) and highly selective alpha1A-AR antagonist. Both of these compounds and (S)-WB4101 seem to act as inverse agonists in a vascular model. The results, which generally validate the logic we followed in designing these eight compounds, are acceptably rationalized by comparative SAR analysis of binding and functional affinities.
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Affiliation(s)
- Marco Pallavicini
- Istituto di Chimica Farmaceutica e Tossicologica, Università degli Studi di Milano, viale Abruzzi 42, I-20131 Milano, Italy
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34
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Perez DM. Structure-function of alpha1-adrenergic receptors. Biochem Pharmacol 2006; 73:1051-62. [PMID: 17052695 PMCID: PMC2034198 DOI: 10.1016/j.bcp.2006.09.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2006] [Revised: 09/07/2006] [Accepted: 09/11/2006] [Indexed: 11/17/2022]
Abstract
The Easson-Stedman hypothesis provided the rationale for the first studies of drug design for the alpha(1)-adrenergic receptor. Through chemical modifications of the catecholamine core structure, the need was established for a protonated amine, a beta-hydroxyl on a chiral center, and an aromatic ring with substitutions capable of hydrogen bonding. After the receptors were cloned and three alpha(1)-adrenergic receptor subtypes were discovered, drug design became focused on the analysis of receptor structure and new interactions were uncovered. It became clear that alpha(1)- and beta-adrenergic receptors did not share stringent homology in the ligand-binding pocket but this difference has allowed for more selective drug design. Novel discoveries on allosterism and agonist trafficking may be used in the future design of therapeutics with fewer side effects. This review will explore past and current knowledge of the structure-function of the alpha(1)-adrenergic receptor subtypes.
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Affiliation(s)
- Dianne M Perez
- Department of Molecular Cardiology, NB5, The Cleveland Clinic Foundation, Lerner Research Institute, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
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35
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Rezmann-Vitti LA, Nero TL, Jackman GP, Machida CA, Duke BJ, Louis WJ, Louis SNS. Role of Tyr356(7.43) and Ser190(4.57) in Antagonist Binding in the Rat β1-Adrenergic Receptor. J Med Chem 2006; 49:3467-77. [PMID: 16759089 DOI: 10.1021/jm050624l] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Site-directed mutagenesis and photoaffinity labeling experiments suggest the existence of at least two distinct binding orientations for aryloxypropanolamine competitive antagonists in the beta-adrenergic receptor (beta-AR), one where the aryloxy moiety is located near transmembrane alpha-helix 7 (tm 7) and another where it is near tm 5. To explore a hydrophobic pocket involving tms 1, 2, 3, and 7 for potential aryloxy interaction sites, we selected Tyr(356(7.43)) and Trp(134(3.28)) in the rat beta(1)-AR for site-directed mutagenesis studies. Ser(190(4.57)) was also investigated, as the equivalent residues are known antagonist interaction sites in the muscarinic M(1) and the dopamine D(2) receptors. Binding affinities (pK(i)) of a series of structurally diverse aryloxypropanolamine competitive antagonists were determined for wild type and Y356A, Y356F, W134A, and S190A mutant rat beta(1)-ARs stably expressed in Chinese hamster ovary cells. To visualize possible antagonist/receptor interactions, the compounds were docked into a three-dimensional model of the wild-type rat beta(1)-AR. The results indicate that Tyr(356(7.43)) is an important aromatic interaction site for five of the eight competitive antagonists studied, whereas none of the compounds appeared to interact directly with Trp(134(3.28)). Only two of the competitive antagonists interacted with Ser(190(4.57)) on tm 4. Overall, the results extend our understanding of how beta(1)-AR competitive antagonists bind to the hydrophobic pocket involving tms 1, 2, 3, and 7; highlight the importance of Tyr(356(7.43)) in this binding pocket; and demonstrate the involvement of tm 4 in competitive antagonist binding.
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Affiliation(s)
- Linda A Rezmann-Vitti
- Department of Medicine, Austin Health, Clinical Pharmacology and Therapeutics Unit, The University of Melbourne, Heidelberg, 3084, Victoria, Australia
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36
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Bautista DL, Morris DH, Stein L, Asher W, Hammitt T. A two model receptor system of the alpha1D adrenergic receptor to describe interactions with epinephrine and BMY7378. J Chem Inf Model 2006; 46:334-44. [PMID: 16426068 DOI: 10.1021/ci050116k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this study, we have developed a two receptor model system to describe the R and R states of G-protein coupled receptors, specifically the alpha(1D) adrenergic receptor. The two models interact with agonist (epinephrine) and antagonist (BMY7378) differently. The active model has increased interactions with epinephrine. The inactive model has increased interactions with BMY7378. We also explored the protonation state of the ligands. When the most basic amine was protonated, we found increased hydrogen bonding and increased aromatic interactions. Protonated epinephrine hydrogen bonds with Asp176 and has aromatic residues Trp172, Trp235, Trp361, and Phe388 within 3 Angstroms. Protonated BMY7378 hydrogen bonds with Trp172 and Lys236 and has aromatic residues Trp172, Trp254, Phe364, Phe384, and Phe388 within 3 Angstroms. We conclude that the two model system is required to represent the two states of the receptor and that protonation of the ligand is also critical.
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Affiliation(s)
- Debra L Bautista
- Chemistry Department, Eastern Kentucky University, Richmond, 40475, USA.
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37
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Kinsella GK, Rozas I, Watson GW. Comparative molecular dynamics simulations of uncomplexed, 'agonist-bound' and 'antagonist-bound' alpha1A adrenoceptor models. Biochem Biophys Res Commun 2005; 333:737-41. [PMID: 15955528 DOI: 10.1016/j.bbrc.2005.05.159] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2005] [Accepted: 05/17/2005] [Indexed: 11/20/2022]
Abstract
Molecular dynamics simulations (2 ns) were conducted on a homology model of the alpha1A adrenoceptor complexed with agonists and antagonists to examine the various receptor conformations induced. These simulations yield insights into the binding site interactions of the active and inactive states of the receptor. Furthermore, our analysis allowed for the selection of candidate sites for future mutagenesis experiments such as of Glu-180, which may be important for antagonist binding. The interactions of conserved residues of the DRY motif in TM-III and the NPxxY motif in TM-VII in the alpha1A adrenoceptor complexes were also examined. The major differences lie in the role of residue Arg-124, which for the agonist complexes formed additional interactions with residues of intracellular loops I and II. Alternatively, for the antagonist complexes, additional interactions were observed for Asn-322 with residues of TM-II and TM-VII.
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Affiliation(s)
- Gemma K Kinsella
- Department of Chemistry, University of Dublin, Trinity College, Dublin 2, Ireland
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38
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Montagne O, Le Corvoisier P, Guenoun T, Laplace M, Crozatier B. Impaired alpha1-adrenergic responses in aged rat hearts. Fundam Clin Pharmacol 2005; 19:331-9. [PMID: 15910657 DOI: 10.1111/j.1472-8206.2005.00333.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To determine age-related changes in the cardiac effect of alpha1-adrenergic stimulation, both cardiomyocyte Ca2+-transient and cardiac protein kinase C (PKC) activity were measured in 3-month- (3MO) and 24-month- (24MO) old Wistar rats. Ca2+ transients obtained under 1 Hz pacing by microfluorimetry of cardiomyocyte loaded with indo-1 (405/480 nm fluorescence ratio) were compared in control conditions (Kreb's solution alone) and after alpha1-adrenergic stimulation (phenylephrine or cirazoline, an alpha1-specific agonist). PKC activity and PKC translocation index (particulate/total activity) were also assayed before and after alpha1-adrenergic stimulation. In 3MO, cirazoline induced a significant increase in Ca2+ transient for a 10(-9) M concentration which returned to control values for larger concentrations. In contrast, in 24MO, we observed a constant negative effect of cirazoline on the Ca2+ transient with a significant decrease at 10(-6) M compared with both baseline and Kreb's solution. Preliminary experiments showed that, in a dose-response curve to phenylephrine, the response of Ca2+ transient was maximal at 10(-7) M. This concentration induced a significant increase in Ca2+ transient in 3MO and a significant decrease in 24MO. The same concentration was chosen to perform PKC activity measurements under alpha1-adrenergic stimulation. In the basal state, PKC particulate activity was higher in 24MO than that in 3MO but was not different in cytosolic fractions; so that the translocation index was higher in 24MO (P < 0.01). After phenylephrine, a translocation of PKC toward the particulate fraction was observed in 3MO but not in 24MO. In conclusion, cardiac alpha1-adrenoceptor response was found to be impaired in aged hearts. The negative effect of alpha1-adrenergic stimulation on Ca2+ transient in cardiomyocytes obtained from old rats can be related to an absence of alpha1-adrenergic-induced PKC translocation.
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Affiliation(s)
- Olivier Montagne
- Unité INSERM U400, Faculté de Médecine de Créteil, Université Paris 12, 94000 Créteil, France
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39
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Kinsella GK, Rozas I, Watson GW. Modelling the Interaction of Catecholamines with the α1A Adrenoceptor Towards a Ligand-induced Receptor Structure. J Comput Aided Mol Des 2005; 19:357-67. [PMID: 16231197 DOI: 10.1007/s10822-005-7553-1] [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: 02/25/2005] [Accepted: 05/18/2005] [Indexed: 10/25/2022]
Abstract
Adrenoceptors are members of the important G protein coupled receptor family for which the detailed mechanism of activation remains unclear. In this study, we have combined docking and molecular dynamics simulations to model the ligand induced effect on an homology derived human alpha1A adrenoceptor. Analysis of agonist/alpha1A adrenoceptor complex interactions focused on the role of the charged amine group, the aromatic ring, the N-methyl group of adrenaline, the beta hydroxyl group and the catechol meta and para hydroxyl groups of the catecholamines. The most critical interactions for the binding of the agonists are consistent with many earlier reports and our study suggests new residues possibly involved in the agonist-binding site, namely Thr-174 and Cys-176. We further observe a number of structural changes that occur upon agonist binding including a movement of TM-V away from TM-III and a change in the interactions of Asp-123 of the conserved DRY motif. This may cause Arg-124 to move out of the TM helical bundle and change the orientation of residues in IC-II and IC-III, allowing for increased affinity of coupling to the G-protein.
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Affiliation(s)
- Gemma K Kinsella
- Department of Chemistry, Trinity College, University of Dublin, Dublin 2, Ireland
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40
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Fumagalli L, Bolchi C, Colleoni S, Gobbi M, Moroni B, Pallavicini M, Pedretti A, Villa L, Vistoli G, Valoti E. QSAR study for a novel series of ortho monosubstituted phenoxy analogues of α1-adrenoceptor antagonist WB4101. Bioorg Med Chem 2005; 13:2547-59. [PMID: 15755656 DOI: 10.1016/j.bmc.2005.01.034] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2004] [Revised: 01/14/2005] [Accepted: 01/21/2005] [Indexed: 11/17/2022]
Abstract
A number of (S)- and (R)-2-[(2-phenoxyethyl)aminomethyl]-1,4-benzodioxanes unsubstituted or ortho monosubstituted at the phenoxy moiety were synthesized and tested in binding assays on the alpha(1a)-AR, alpha(1b)-AR, alpha(1d)-AR and the 5-HT(1A) receptor. The affinity values of the new compounds 1-16 were compared with those of the enantiomers of the 2,6-dimethoxyphenoxy analogue, the well-known alpha(1) antagonist WB4101, finding that the unsubstituted derivative (S)-1 and the o-methyl, the o-t-butyl, the o-fluoro and the o-methoxy derivatives, (S)-2, (S)-4, (S)-8 and (S)-16, respectively, display a significantly specific 5-HT(1A) affinity, very close, with the exception of (S)-4, to the almost nanomolar one of (S)-WB4101. Otherwise, sensible affinity decreases were recorded for the three alpha(1)-AR subtypes. A classical quantitative structure-activity relationship (Hansch) analysis was successfully applied to compounds (S)-1 to (S)-16 and (S)-WB4101 to rationalize such binding data.
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Affiliation(s)
- Laura Fumagalli
- Istituto di Chimica Farmaceutica e Tossicologica, Università di Milano, viale Abruzzi 42, I-20131 Milano, Italy
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41
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Lei B, Morris DP, Smith MP, Svetkey LP, Newman MF, Rotter JI, Buchanan TA, Beckstrom-Sternberg SM, Green ED, Schwinn DA. Novel human alpha1a-adrenoceptor single nucleotide polymorphisms alter receptor pharmacology and biological function. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2005; 371:229-39. [PMID: 15900517 PMCID: PMC2367253 DOI: 10.1007/s00210-005-1019-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2004] [Accepted: 12/21/2004] [Indexed: 11/26/2022]
Abstract
We identified nine naturally-occurring human single nucleotide polymorphisms (SNPs) in the alpha(1a)-adrenoceptor (alpha(1a)AR) coding region, seven of which result in amino acid change. Utilizing rat-1 fibroblasts stably expressing wild type alpha(1a)AR or each SNP at both high and low levels, we investigated the effect of these SNPs on receptor function. Compared with wild type, two SNPs (R166K, V311I) cause a decrease in binding affinity for agonists norepinephrine, epinephrine, and phenylephrine, and also shift the dose-response curve for norepinephrine stimulation of inositol phosphate (IP) production to the right (reduced potency) without altering maximal IP activity. In addition, SNP V311I and I200S display altered antagonist binding. Interestingly, a receptor with SNP G247R (located in the third intracellular loop) displays increased maximal receptor IP activity and stimulates cell growth. The increased receptor signaling for alpha(1a)AR G247R is not mediated by altered ligand binding or a deficiency in agonist-mediated desensitization, but appears to be related to enhanced receptor-G protein coupling. In conclusion, four naturally-occurring human alpha(1a)AR SNPs induce altered receptor pharmacology and/or biological activity. This finding has potentially important implications in many areas of medicine and can be used to guide alpha(1a)AR SNP choice for future clinical studies.
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MESH Headings
- Adrenergic alpha-Agonists/pharmacology
- Adrenergic alpha-Antagonists/pharmacology
- Amino Acid Sequence
- Amino Acid Substitution
- Animals
- Cell Division/genetics
- Cells, Cultured
- Dose-Response Relationship, Drug
- GTP-Binding Proteins/metabolism
- Humans
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Phosphoric Monoester Hydrolases/metabolism
- Polymorphism, Single Nucleotide
- Radioligand Assay
- Rats
- Receptors, Adrenergic, alpha-1/drug effects
- Receptors, Adrenergic, alpha-1/genetics
- Receptors, Adrenergic, alpha-1/metabolism
- Signal Transduction
- Transfection
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Affiliation(s)
- Beilei Lei
- Department of Anesthesiology, Duke University Medical Center, Box 3094 Durham, NC, 27710, USA
- Department of Pharmacology/Cancer Biology Duke University Medical Center, Durham, NC, USA
| | - Daniel P. Morris
- Department of Anesthesiology, Duke University Medical Center, Box 3094 Durham, NC, 27710, USA
- Department of Pharmacology/Cancer Biology Duke University Medical Center, Durham, NC, USA
| | - Michael P. Smith
- Department of Anesthesiology, Duke University Medical Center, Box 3094 Durham, NC, 27710, USA
- Department of Pharmacology/Cancer Biology Duke University Medical Center, Durham, NC, USA
| | - Laura P. Svetkey
- Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | - Mark F. Newman
- Department of Anesthesiology, Duke University Medical Center, Box 3094 Durham, NC, 27710, USA
| | - Jerome I. Rotter
- Department of Medicine, Cedars-Sinai Medical Center and the University of California, Los Angeles, CA, USA
- Department of Pediatrics, Cedars-Sinai Medical Center and the University of California, Los Angeles, CA, USA
- Department of Human Genetics, Cedars-Sinai Medical Center and the University of California, Los Angeles, CA, USA
| | - Thomas A. Buchanan
- Department of Medicine, University of Southern California, Los Angeles, CA, USA
| | | | - Eric D. Green
- Genome Technology Branch and NIH Intramural Sequencing Center, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Debra A. Schwinn
- Department of Anesthesiology, Duke University Medical Center, Box 3094 Durham, NC, 27710, USA, e-mail: , Tel.: +1-919-6814781, Fax: +1-919-6814776
- Department of Pharmacology/Cancer Biology Duke University Medical Center, Durham, NC, USA
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42
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Evers A, Klabunde T. Structure-based Drug Discovery Using GPCR Homology Modeling: Successful Virtual Screening for Antagonists of the Alpha1A Adrenergic Receptor. J Med Chem 2005; 48:1088-97. [PMID: 15715476 DOI: 10.1021/jm0491804] [Citation(s) in RCA: 179] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this paper, we describe homology modeling of the alpha1A receptor based on the X-ray structure of bovine rhodopsin. The protein model has been generated by applying ligand-supported homology modeling, using mutational and ligand SAR data to guide the protein modeling procedure. We performed a virtual screening of the company's compound collection to test how well this model is suited to identify alpha1A antagonists. We applied a hierarchical virtual screening procedure guided by 2D filters and three-dimensional pharmacophore models. The ca. 23,000 filtered compounds were docked into the alpha1A homology model with GOLD and scored with PMF. From the top-ranked compounds, 80 diverse compounds were tested in a radioligand displacement assay. 37 compounds revealed K(i) values better than 10 microM; the most active compound binds with 1.4 nM to the alpha1A receptor. Our findings suggest that rhodopsin-based homology models may be used as the structural basis for GPCR lead finding and compound optimization.
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Affiliation(s)
- Andreas Evers
- Aventis Pharma Deutschland GmBH, Ein Unternehmen der Sanofi-Aventis Gruppe, DI&A Chemistry, Computational Chemistry, Industriepark Höchst, Building G838, D-65926 Frankfurt am Main, Germany.
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43
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Gouldson PR, Kidley NJ, Bywater RP, Psaroudakis G, Brooks HD, Diaz C, Shire D, Reynolds CA. Toward the active conformations of rhodopsin and the beta2-adrenergic receptor. Proteins 2004; 56:67-84. [PMID: 15162487 DOI: 10.1002/prot.20108] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Using sets of experimental distance restraints, which characterize active or inactive receptor conformations, and the X-ray crystal structure of the inactive form of bovine rhodopsin as a starting point, we have constructed models of both the active and inactive forms of rhodopsin and the beta2-adrenergic G-protein coupled receptors (GPCRs). The distance restraints were obtained from published data for site-directed crosslinking, engineered zinc binding, site-directed spin-labeling, IR spectroscopy, and cysteine accessibility studies conducted on class A GPCRs. Molecular dynamics simulations in the presence of either "active" or "inactive" restraints were used to generate two distinguishable receptor models. The process for generating the inactive and active models was validated by the hit rates, yields, and enrichment factors determined for the selection of antagonists in the inactive model and for the selection of agonists in the active model from a set of nonadrenergic GPCR drug-like ligands in a virtual screen using ligand docking software. The simulation results provide new insights into the relationships observed between selected biochemical data, the crystal structure of rhodopsin, and the structural rearrangements that occur during activation.
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44
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Kinsella GK, Rozas I, Watson GW. Computational development of an α1A-adrenoceptor model in a membrane mimic. Biochem Biophys Res Commun 2004; 324:916-21. [PMID: 15474515 DOI: 10.1016/j.bbrc.2004.09.128] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2004] [Indexed: 10/26/2022]
Abstract
A number of subtypes of the alpha-adrenoceptor have been identified; however, knowledge of the three-dimensional structures of such membrane proteins is limited, and no crystal structure of an alpha-adrenoceptor is available to date. We have developed and analysed homology models of the alpha1A-adrenoceptor subtype based on the bovine rhodopsin crystal structure (1l9 h). Subsequent structural refinement was performed through molecular dynamics simulations using the Amber 7 suite of programs with a biphasic H2O/CHCl3/H2O cell utilised to mimic the receptor's natural membrane environment.
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Affiliation(s)
- Gemma K Kinsella
- Department of Chemistry, Trinity College Dublin, Dublin 2, Ireland
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45
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Bolchi C, Catalano P, Fumagalli L, Gobbi M, Pallavicini M, Pedretti A, Villa L, Vistoli G, Valoti E. Structure–affinity studies for a novel series of homochiral naphtho and tetrahydronaphtho analogues of α1 antagonist WB-4101. Bioorg Med Chem 2004; 12:4937-51. [PMID: 15336273 DOI: 10.1016/j.bmc.2004.06.040] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2004] [Accepted: 06/28/2004] [Indexed: 11/25/2022]
Abstract
A number of enantiomeric pairs of naphthodioxane, tetrahydronaphthodioxane and naphthoxy analogues of WB-4101 (1) were designed and synthesized in order to improve the selectivity profile of the parent compound, hopefully in favour of the alpha(1a)-AR with respect to the other two alpha(1) subtypes and the 5-HT(1A) receptor. The new compounds 2-8 and, in addition, the two enantiomers of 1 were tested in binding assays on the alpha(1a)-AR, alpha(1b)-AR, alpha(1d)-AR, and the 5-HT(1A) receptor. Two of them, namely the naphtho- and tetrahydronaphthodioxane derivatives (S)-2 and (S)-3, showed lower, but significantly more specific alpha(1a) affinity than (S)-1, while the two enantiomers of the 2-methoxy-1-naphthoxy analogue 6 maintained most of the very high alpha(1a) affinity of (S)-1 and its alpha(1a) versus alpha(1b) selectivity slightly increasing the alpha(1a)/alpha(1d) and alpha(1a)/5HT(1A) affinity ratios. The SAR data were evaluated in the light of known alpha(1) subtype pharmacophores and of the alpha(1a)-AR binding mode of WB-4101 resultant from literature mutagenesis studies disclosing some interesting consonances with these models.
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Affiliation(s)
- Cristiano Bolchi
- Istituto di Chimica Farmaceutica e Tossicologica, Universitá degli Studi di Milano, viale Abruzzi 42, I-20131 Milano, Italy
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Pedretti A, Elena Silva M, Villa L, Vistoli G. Binding site analysis of full-length α1a adrenergic receptor using homology modeling and molecular docking. Biochem Biophys Res Commun 2004; 319:493-500. [PMID: 15178433 DOI: 10.1016/j.bbrc.2004.04.149] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2004] [Indexed: 11/28/2022]
Abstract
The recent availability of crystal structure of bovine rhodopsin offers new opportunities in order to approach the construction of G protein coupled receptors. This study focuses the attention on the modeling of full-length alpha(1a) adrenergic receptor (alpha(1a)-AR) due to its biological role and significant implications in pharmacological treatment of benign prostate hyperplasia. This work could be considered made up by two main steps: (a) the construction of full structure of alpha(1a)-AR, through homology modeling methods; (b) the automated docking of an endogenous agonist, norepinephrine, and of an antagonist, WB-4101, using BioDock program. The obtained results highlight the key residues involved in binding sites of both agonists and antagonists, confirming the mutagenesis data and giving new suggestions for the rational design of selective ligands.
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Affiliation(s)
- Alessandro Pedretti
- Istituto di Chimica Farmaceutica, Faculty of Pharmacy, Viale Abruzzi, 42 University of Milan, 20131 Milan, Italy
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Balle T, Andersen K, Søby KK, Liljefors T. Alpha(1) adrenoceptor subtype selectivity. 3D-QSAR models for a new class of alpha(1) adrenoceptor antagonists derived from the novel antipsychotic sertindole. J Mol Graph Model 2003; 21:523-34. [PMID: 12676239 DOI: 10.1016/s1093-3263(03)00120-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Receptor-binding affinities for the alpha(1) adrenoceptor subtypes alpha(1a), alpha(1b) and alpha(1d) for a series of 39 alpha(1) adrenoceptor antagonists derived from the antipsychotic sertindole are reported. The SAR of the compounds with respect to affinity for the alpha(1a), alpha(1b) and alpha(1d) adrenoceptor subtypes as well as affinity obtained by an alpha(1) assay (rat brain membranes) were investigated using a 3D-QSAR approach based on the GRID/GOLPE methodology. Good statistics (r(2)=0.91-0.96; q(2)=0.65-0.73) were obtained with the combination of the water (OH2) and methyl (C3) probes. The combination of steric repulsion and electrostatic attractions explain the affinities of the included molecules. The adrenergic alpha(1a) receptor seems to be more tolerant to large substituents in the area between the indole 5- and 6-positions compared to the adrenergic alpha(1b) and alpha(1d) receptor subtypes. There seems to be minor differences in the position of areas in the alpha(1b) receptor compared to alpha(1a) and alpha(1d) receptors where electrostatic interaction between the molecules and the receptor (OH2 probe) contribute to increased affinity. These observations may be used in the design of new subtype selective compounds. In addition, the model based on biological data from an alpha(1) assay (rat brain membranes) resembles the model for the alpha(1b) adrenoceptor subtype.
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Affiliation(s)
- Thomas Balle
- Medicinal Chemistry Research, H Lundbeck A/S, 9 Ottiliavej, 2500 Valby, Denmark
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Filipek S, Teller DC, Palczewski K, Stenkamp R. The crystallographic model of rhodopsin and its use in studies of other G protein-coupled receptors. ANNUAL REVIEW OF BIOPHYSICS AND BIOMOLECULAR STRUCTURE 2003; 32:375-97. [PMID: 12574068 PMCID: PMC1351250 DOI: 10.1146/annurev.biophys.32.110601.142520] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
G protein-coupled receptors (GPCRs) are integral membrane proteins that respond to environmental signals and initiate signal transduction pathways activating cellular processes. Rhodopsin is a GPCR found in rod cells in retina where it functions as a photopigment. Its molecular structure is known from cryo-electron microscopic and X-ray crystallographic studies, and this has reshaped many structure/function questions important in vision science. In addition, this first GPCR structure has provided a structural template for studies of other GPCRs, including many known drug targets. After presenting an overview of the major structural elements of rhodopsin, recent literature covering the use of the rhodopsin structure in analyzing other GPCRs will be summarized. Use of the rhodopsin structural model to understand the structure and function of other GPCRs provides strong evidence validating the structural model.
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Affiliation(s)
- Slawomir Filipek
- Departments of Biological Structure
- Biomolecular Structure Center, University of Washington, Seattle, Washington 98195; ;;
- International Institute of Molecular and Cell Biology and
- Faculty of Chemistry, University of Warsaw, 02-109 Warsaw, Poland;
| | - David C. Teller
- Biochemistry
- Biomolecular Structure Center, University of Washington, Seattle, Washington 98195; ;;
| | | | - Ronald Stenkamp
- Departments of Biological Structure
- Biomolecular Structure Center, University of Washington, Seattle, Washington 98195; ;;
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Ishiguro M, Futabayashi Y, Ohnuki T, Ahmed M, Muramatsu I, Nagatomo T. Identification of binding sites of prazosin, tamsulosin and KMD-3213 with α1-adrenergic receptor subtypes by molecular modeling. Life Sci 2002; 71:2531-41. [PMID: 12270758 DOI: 10.1016/s0024-3205(02)02077-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This investigation was performed to assess the importance of interaction in the bindings of selective and nonselective alpha(1)-antagonists to alpha(1)-adrenergic receptor (alpha(1)-AR) subtypes using molecular modeling. The alpha(1)-antagonists used in this study were prazosin, tamsulosin and KMD-3213. Molecular modeling was performed on Octane 2 workstation (Silicon Graphics) using Discover/Insight II software (Molecular Simulations Inc.). Through molecular modeling, possible binding sites for these drugs were suggested to lie between transmembrane domains (TM) 3, 4, 5 and 6 of the alpha(1)-AR subtypes. In prazosin, the 4-amino group, 1-nitrogen atom and two methoxy groups of quinazoline ring possibly interact with the amino acids in TM3, TM5 and TM6 of alpha(1)-ARs. In tamsulosin, amine group of ethanyl amine chain, methoxy group of benzene ring and sulfonamide nitrogen of benzene ring interacts in TM3, TM4 and TM5 of alpha(1)-ARs. In KMD-3213, amine of ethyl amine chain and indoline nitrogen of this compound possibly interact within TM3 and TM5 of alpha(1)-ARs. Amide nitrogen of KMD-3213 also interacts within TM4 of alpha(1A)-AR. The results of the present study suggested that prazosin has similar binding sites in all the alpha(1)-AR subtypes while tamsulosin interacts at higher number of sites with alpha(1D)-subtype than other alpha(1)-AR subtypes. KMD-3213 being an alpha(1A)-AR selective ligand, binds to higher number of sites of alpha(1A) subtype than to other subtypes. All these amino acids are located near the extracellular loop. These findings are consistent with the previous studies that antagonists bind higher in the pocket closer to the extracellular surface unlike agonist binding.
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Affiliation(s)
- Masaji Ishiguro
- Suntory Institute for Bioorganic Research, 1-1-1 Wakayamadai, Shimahon-cho, Mishima-gun, Osaka, Japan.
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