1
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Zlotos DP, Mandour YM, Jensen AA. Strychnine and its mono- and dimeric analogues: a pharmaco-chemical perspective. Nat Prod Rep 2022; 39:1910-1937. [PMID: 35380133 DOI: 10.1039/d1np00079a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Covering: up to November 2021Since its isolation in 1818, strychnine has attracted the attention of a plethora of chemists and pharmacologists who have established its structure, developed total syntheses, and examined its complex pharmacology. While numerous reviews on structure elucidation and total synthesis of strychnine are available, reports on structure-activity relationships (SARs) of this fascinating alkaloid are rare. In this review, we present and discuss structures, synthetic approaches, metabolic transformations, and the diverse pharmacological actions of strychnine and its mono- and dimeric analogues. Particular attention is given to its SARs at glycine receptors (GlyRs) in light of recently published high-resolution structures of strychnine-GlyR complexes. Other pharmacological actions of strychnine and its derivatives, such as their antagonistic properties at nicotinic acetylcholine receptors (nAChRs), allosteric modulation of muscarinic acetylcholine receptors as well as anti-cancer and anti-plasmodial effects are also critically reviewed, and possible future developments in the field are discussed.
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Affiliation(s)
- Darius P Zlotos
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Biotechnology, The German University in Cairo, New Cairo City, 11835 Cairo, Egypt.
| | - Yasmine M Mandour
- School of Life and Medical Sciences, University of Hertfordshire hosted by Global Academic Foundation, New Administrative Capital, Cairo, Egypt
| | - Anders A Jensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2100 Copenhagen, Denmark
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2
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Bueno RV, Davis S, Dawson A, Ondachi PW, Carroll FI, Hunter WN. Interactions between 2′-fluoro-(carbamoylpyridinyl)deschloroepibatidine analogues and acetylcholine-binding protein inform on potent antagonist activity against nicotinic receptors. Acta Crystallogr D Struct Biol 2022; 78:353-362. [PMID: 35234149 PMCID: PMC8900824 DOI: 10.1107/s2059798322000754] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 01/21/2022] [Indexed: 11/29/2022] Open
Abstract
The binding of a series of epibatidine derivatives to acetylcholine-binding protein was investigated using biolayer interferometry. The structures of three complexes inform discussion on the biological implications for interactions with nicotinic acetylcholine receptor subtypes, which are important targets for control of pain. Low-nanomolar binding constants were recorded for a series of six 2′-fluoro-(carbamoylpyridinyl)deschloroepibatidine analogues with acetylcholine-binding protein (AChBP). The crystal structures of three complexes with AChBP reveal details of molecular recognition in the orthosteric binding site and imply how the other three ligands bind. Comparisons exploiting AChBP as a surrogate for α4β2 and α7 nicotinic acetylcholine receptors (nAChRs) suggest that the key interactions are conserved. The ligands interact with the same residues as the archetypal nAChR agonist nicotine yet display greater affinity, thereby rationalizing their in vivo activity as potent antagonists of nicotine-induced antinociception. An oxyanion-binding site is formed on the periphery of the AChBP orthosteric site by Lys42, Asp94, Glu170 and Glu210. These residues are highly conserved in the human α4, β2 and α7 nAChR sequences. However, specific sequence differences are discussed that could contribute to nAChR subtype selectivity and in addition may represent a point of allosteric modulation. The ability to engage with this peripheral site may explain, in part, the function of a subset of ligands to act as agonists of α7 nAChR.
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3
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Ho TNT, Abraham N, Lewis RJ. Unique Pharmacological Properties of α-Conotoxin OmIA at α7 nAChRs. Front Pharmacol 2021; 12:803397. [PMID: 34955864 PMCID: PMC8692984 DOI: 10.3389/fphar.2021.803397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 11/22/2021] [Indexed: 11/13/2022] Open
Abstract
OmIA, isolated from Conus omaria venom, is a potent antagonist at α7 nAChRs. We determined the co-crystal structure of OmIA with Lymnae stagnalis acetylcholine binding protein (Ls-AChBP) that identified His5, Val10 and Asn11 as key determinants for the high potency of OmIA at α7 nAChRs. Remarkably, despite a competitive binding mode observed in the co-crystal structure, OmIA and analogues displayed functional insurmountable antagonism at α7 and α3β4 nAChRs, except OmIA analogues having long side chain at position 10 ([V10Q]OmIA and [V10L]OmIA), which were partial insurmountable antagonist at α7 nAChRs in the presence of type II positive allosteric modulators (PAMs). A “two-state, two-step” model was used to explain these observations, with [V10Q]OmIA and [V10L]OmIA co-existing in a fast reversible/surmountable as well as a tight binding/insurmountable state. OmIA and analogues also showed biphasic-inhibition at α7 nAChRs in the presence of PNU120596, with a preference for the high-affinity binding site following prolonged exposure. The molecular basis of binding and complex pharmacological profile of OmIA at α7 nAChRs presented in here expands on the potential of α-conotoxins to probe the pharmacological properties of nAChRs and may help guide the development novel α7 modulators.
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Affiliation(s)
- Thao N T Ho
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| | - Nikita Abraham
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| | - Richard J Lewis
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
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4
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Clementson S, Matheu SA, Rørsted EM, Pedersen H, Jensen AA, Clausen RP, Vital P, Glibstrup E, Jessing M, Kristensen JL. Erythrina Alkaloid Analogues as nAChR Antagonists-A Flexible Platform for Leads in Drug Discovery. J Org Chem 2021; 86:8248-8262. [PMID: 34061521 DOI: 10.1021/acs.joc.1c00707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Erythrina alkaloids and their central nervous system effects have been studied for over a century, mainly due to their potent antagonistic actions at β2-containing nicotinic acetylcholine receptors (nAChRs). In the present work, we report a synthetic approach giving access to a diverse set of Erythrina natural product analogues and present the enantioselective total synthesis of (+)-Cocculine and (+)-Cocculidine, both found to be potent antagonists of the β2-containing nAChRs.
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Affiliation(s)
- Sebastian Clementson
- Molecular Discovery and Innovation, H. Lundbeck A/S, Ottiliavej 9, Valby 2500, Denmark.,Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, Copenhagen 2100, Denmark
| | - Sergio Armentia Matheu
- Molecular Discovery and Innovation, H. Lundbeck A/S, Ottiliavej 9, Valby 2500, Denmark.,Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, Copenhagen 2100, Denmark
| | - Emil Märcher Rørsted
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, Copenhagen 2100, Denmark
| | - Henrik Pedersen
- Molecular Discovery and Innovation, H. Lundbeck A/S, Ottiliavej 9, Valby 2500, Denmark
| | - Anders A Jensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, Copenhagen 2100, Denmark
| | - Rasmus P Clausen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, Copenhagen 2100, Denmark
| | - Paulo Vital
- Molecular Discovery and Innovation, H. Lundbeck A/S, Ottiliavej 9, Valby 2500, Denmark
| | - Emil Glibstrup
- Molecular Discovery and Innovation, H. Lundbeck A/S, Ottiliavej 9, Valby 2500, Denmark
| | - Mikkel Jessing
- Molecular Discovery and Innovation, H. Lundbeck A/S, Ottiliavej 9, Valby 2500, Denmark
| | - Jesper L Kristensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, Copenhagen 2100, Denmark
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5
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Ho TNT, Abraham N, Lewis RJ. Structure-Function of Neuronal Nicotinic Acetylcholine Receptor Inhibitors Derived From Natural Toxins. Front Neurosci 2020; 14:609005. [PMID: 33324158 PMCID: PMC7723979 DOI: 10.3389/fnins.2020.609005] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 10/30/2020] [Indexed: 12/19/2022] Open
Abstract
Neuronal nicotinic acetylcholine receptors (nAChRs) are prototypical cation-selective, ligand-gated ion channels that mediate fast neurotransmission in the central and peripheral nervous systems. nAChRs are involved in a range of physiological and pathological functions and hence are important therapeutic targets. Their subunit homology and diverse pentameric assembly contribute to their challenging pharmacology and limit their drug development potential. Toxins produced by an extensive range of algae, plants and animals target nAChRs, with many proving pivotal in elucidating receptor pharmacology and biochemistry, as well as providing templates for structure-based drug design. The crystal structures of these toxins with diverse chemical profiles in complex with acetylcholine binding protein (AChBP), a soluble homolog of the extracellular ligand-binding domain of the nAChRs and more recently the extracellular domain of human α9 nAChRs, have been reported. These studies have shed light on the diverse molecular mechanisms of ligand-binding at neuronal nAChR subtypes and uncovered critical insights useful for rational drug design. This review provides a comprehensive overview and perspectives obtained from structure and function studies of diverse plant and animal toxins and their associated inhibitory mechanisms at neuronal nAChRs.
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Affiliation(s)
| | | | - Richard J. Lewis
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
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6
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Basak S, Kumar A, Ramsey S, Gibbs E, Kapoor A, Filizola M, Chakrapani S. High-resolution structures of multiple 5-HT 3AR-setron complexes reveal a novel mechanism of competitive inhibition. eLife 2020; 9:e57870. [PMID: 33063666 PMCID: PMC7655109 DOI: 10.7554/elife.57870] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 10/15/2020] [Indexed: 12/13/2022] Open
Abstract
Serotonin receptors (5-HT3AR) play a crucial role in regulating gut movement, and are the principal target of setrons, a class of high-affinity competitive antagonists, used in the management of nausea and vomiting associated with radiation and chemotherapies. Structural insights into setron-binding poses and their inhibitory mechanisms are just beginning to emerge. Here, we present high-resolution cryo-EM structures of full-length 5-HT3AR in complex with palonosetron, ondansetron, and alosetron. Molecular dynamic simulations of these structures embedded in a fully-hydrated lipid environment assessed the stability of ligand-binding poses and drug-target interactions over time. Together with simulation results of apo- and serotonin-bound 5-HT3AR, the study reveals a distinct interaction fingerprint between the various setrons and binding-pocket residues that may underlie their diverse affinities. In addition, varying degrees of conformational change in the setron-5-HT3AR structures, throughout the channel and particularly along the channel activation pathway, suggests a novel mechanism of competitive inhibition.
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Affiliation(s)
- Sandip Basak
- Department of Physiology and Biophysics, Case Western Reserve UniversityClevelandUnited States
- Cleveland Center for Membrane and Structural Biology, Case Western Reserve UniversityClevelandUnited States
| | - Arvind Kumar
- Department of Physiology and Biophysics, Case Western Reserve UniversityClevelandUnited States
- Cleveland Center for Membrane and Structural Biology, Case Western Reserve UniversityClevelandUnited States
| | - Steven Ramsey
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Eric Gibbs
- Department of Physiology and Biophysics, Case Western Reserve UniversityClevelandUnited States
- Cleveland Center for Membrane and Structural Biology, Case Western Reserve UniversityClevelandUnited States
| | - Abhijeet Kapoor
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Marta Filizola
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Sudha Chakrapani
- Department of Physiology and Biophysics, Case Western Reserve UniversityClevelandUnited States
- Cleveland Center for Membrane and Structural Biology, Case Western Reserve UniversityClevelandUnited States
- Department of Neuroscience, School of Medicine, Case Western Reserve UniversityClevelandUnited States
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7
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Modulation of cholinergic activity through lynx prototoxins: Implications for cognition and anxiety regulation. Neuropharmacology 2020; 174:108071. [PMID: 32298703 PMCID: PMC7785133 DOI: 10.1016/j.neuropharm.2020.108071] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 03/16/2020] [Accepted: 03/24/2020] [Indexed: 02/08/2023]
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8
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Gulsevin A, Papke RL, Horenstein N. In Silico Modeling of the α7 Nicotinic Acetylcholine Receptor: New Pharmacological Challenges Associated with Multiple Modes of Signaling. Mini Rev Med Chem 2020; 20:841-864. [PMID: 32000651 PMCID: PMC8719523 DOI: 10.2174/1389557520666200130105256] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 11/06/2019] [Accepted: 11/07/2019] [Indexed: 12/13/2022]
Abstract
The α7 nicotinic acetylcholine receptor is a homopentameric ion-channel of the Cys-loop superfamily characterized by its low probability of opening, high calcium permeability, and rapid desensitization. The α7 receptor has been targeted for the treatment of the cognitive symptoms of schizophrenia, depression, and Alzheimer's disease, but it is also involved in inflammatory modulation as a part of the cholinergic anti-inflammatory pathway. Despite its functional importance, in silico studies of the α7 receptor cannot produce a general model explaining the structural features of receptor activation, nor predict the mode of action for various ligand classes. Two particular problems in modeling the α7 nAChR are the absence of a high-resolution structure and the presence of five potentially nonequivalent orthosteric ligand binding sites. There is wide variability regarding the templates used for homology modeling, types of ligands investigated, simulation methods, and simulation times. However, a systematic survey focusing on the methodological similarities and differences in modeling α7 has not been done. In this work, we make a critical analysis of the modeling literature of α7 nAChR by comparing the findings of computational studies with each other and with experimental studies under the main topics of structural studies, ligand binding studies, and comparisons with other nAChR. In light of our findings, we also summarize current problems in the field and make suggestions for future studies concerning modeling of the α7 receptor.
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Affiliation(s)
- Alican Gulsevin
- Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, FL, 32611-7200, United States
| | - Roger L Papke
- Department of Pharmacology and Therapeutics, University of Florida, P.O. Box 100267, Gainesville, FL 32610, United States
| | - Nicole Horenstein
- Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, FL, 32611-7200, United States
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9
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Yu R, Tae HS, Xu Q, Craik DJ, Adams DJ, Jiang T, Kaas Q. Molecular dynamics simulations of dihydro-β-erythroidine bound to the human α4β2 nicotinic acetylcholine receptor. Br J Pharmacol 2019; 176:2750-2763. [PMID: 31062355 DOI: 10.1111/bph.14698] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 03/20/2019] [Accepted: 04/10/2019] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND AND PURPOSE The heteromeric α4β2 nicotinic acetylcholine receptor (nAChR) is abundant in the human brain and is associated with a range of CNS disorders. This nAChR subtype has been recently crystallised in a conformation that was proposed to represent a desensitised state. Here, we investigated the conformational transition mechanism of this nAChR from a desensitised to a closed/resting state. EXPERIMENTAL APPROACH The competitive antagonist dihydro-β-erythroidine (DHβE) was modelled by replacement of the agonist nicotine in the α4β2 nAChR experimental structure. DHβE is used both in vitro and in vivo for its ability to block α4β2 nAChRs. This system was studied by three molecular dynamics simulations with a combined simulation time of 2.6 μs. Electrophysiological studies of mutated receptors were performed to validate the simulation results. KEY RESULTS The relative positions of the extracellular and transmembrane domains in the models are distinct from those of the desensitised state structure and are compatible with experimental structures of Cys-loop receptors captured in a closed/resting state. CONCLUSIONS AND IMPLICATIONS Our model suggests that the side chains of α4 L257 (9') and α4 L264 (16') are the main constrictions in the transmembrane pore. The involvement of position 9' in channel gating is well established, but position 16' was only previously identified as a gate for the bacterial channels, ELIC and GLIC. L257 but not L264 was found to influence the slow component of desensitisation. The structure of the antagonist-bound state proposed here should be valuable for the development of therapeutic or insecticide compounds.
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Affiliation(s)
- Rilei Yu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China.,Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Han-Shen Tae
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW, Australia
| | - Qingliang Xu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China.,Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - David J Adams
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW, Australia
| | - Tao Jiang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China.,Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Quentin Kaas
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
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10
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Discovery, cocrystallization and biological evaluation of novel piperidine derivatives as high affinity Ls-AChBP ligands possessing α7 nAChR activities. Eur J Med Chem 2018; 160:37-48. [PMID: 30317024 DOI: 10.1016/j.ejmech.2018.09.073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 09/05/2018] [Accepted: 09/30/2018] [Indexed: 11/23/2022]
Abstract
A series of novel pyridine-substituted piperidine derivatives were discovered as low nanomolar Ls-AChBP ligands with α7 nAChR partial agonism or antagonism activities. A high-resolution antagonist-bound Ls-AChBP complex was successfully resolved with a classic Loop C opening phenomenon and unique sulfur-π interactions which deviated from our previous docking mode to a large extent. With the knowledge of the co-complex, 27 novel piperidine derivatives were designed and synthesized. The structure-activity relationships (SARs) of the aromatic and pyridine regions were well established and binding modes were illustrated with the help of molecular docking which indicated that interactions with Trp 143 and the "water bridge" are essential for the high binding affinities. Halogen bonding as well as the space around 5'- or 6'- position of the pyridine ring was also proposed to influence the binding conformation of the compounds. Notably, two enantiomers of compound 2 showed opposite functions toward α7 nAChR and compound (S)-2 showed sub-nanomolar affinity (Ki = 0.86 nM) on Ls-AChBP and partial agonism (pEC50 = 4.69 ± 0.11,Emax = 36.1%) on α7 nAChR with reasonable pharmacokinetics (PK) properties and fine ability of blood-brain-barrier (BBB) penetration. This study provided promising hits to develop candidates targeting nAChR-related CNS diseases.
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11
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Chiodo L, Malliavin TE, Giuffrida S, Maragliano L, Cottone G. Closed-Locked and Apo-Resting State Structures of the Human α7 Nicotinic Receptor: A Computational Study. J Chem Inf Model 2018; 58:2278-2293. [PMID: 30359518 DOI: 10.1021/acs.jcim.8b00412] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nicotinic acetylcholine receptors, belonging to the Cys-loop superfamily of ligand-gated ion channels (LGICs), are membrane proteins present in neurons and at neuromuscular junctions. They are responsible for signal transmission, and their function is regulated by neurotransmitters, agonists, and antagonists drugs. A detailed knowledge of their conformational transition in response to ligand binding is critical to understanding the basis of ligand-receptor interaction, in view of new pharmacological approaches to control receptor activity. However, the scarcity of experimentally derived structures of human channels makes this perspective extremely challenging. To contribute overcoming this issue, we have recently reported structural models for the open and the desensitized states of the human α7 nicotinic receptor. Here, we provide all-atom structural models of the same receptor in two different nonconductive states. The first structure, built via homology modeling and relaxed with extensive Molecular Dynamics simulations, represents the receptor bound to the natural antagonist α-conotoxin ImI. After comparison with available experimental data and computational models of other eukaryotic LGICs, we deem it consistent with the "closed-locked" state. The second model, obtained with simulations from the spontaneous relaxation of the open, agonist-bound α7 structure after ligand removal, recapitulates the characteristics of the apo-resting state of the receptor. These results add to our previous work on the active and desensitized state conformations, contributing to the structural characterization of the conformational landscape of the human α7 receptor and suggesting benchmarks to discriminate among conformations found in experiments or in simulations of LGICs. In particular key interactions at the interface between the extracellular domain and the transmembrane domain are identified, that could be critical to the α7 receptor function.
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Affiliation(s)
- Letizia Chiodo
- Department of Engineering , Campus Bio-Medico University of Rome , Via Á. del Portillo 21 , 00128 Rome , Italy
| | - Thérèse E Malliavin
- Institut Pasteur and CNRS UMR 3528, Unité de Bioinformatique Structurale , 25-28 rue du Dr Roux , 75015 Paris , France.,Centre de Bioinformatique, Biostatistique et Biologie Intégrative , Institut Pasteur and CNRS USR 3756 , 25-28 rue du Dr Roux , 75015 Paris , France
| | - Sergio Giuffrida
- Department of Physics and Chemistry , University of Palermo , Viale delle Scienze Ed. 17 , 90128 Palermo , Italy
| | - Luca Maragliano
- Center for Synaptic Neuroscience and Technology (NSYN@UniGe) , Istituto Italiano di Tecnologia , Largo Rosanna Benzi, 10 , 16132 Genoa , Italy.,IRCCS Ospedale Policlinico San Martino , Largo Rosanna Benzi 10 , 16132 Genoa , Italy
| | - Grazia Cottone
- Department of Physics and Chemistry , University of Palermo , Viale delle Scienze Ed. 17 , 90128 Palermo , Italy
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12
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Wu X, Tae HS, Huang YH, Adams DJ, Craik DJ, Kaas Q. Stoichiometry dependent inhibition of rat α3β4 nicotinic acetylcholine receptor by the ribbon isomer of α-conotoxin AuIB. Biochem Pharmacol 2018; 155:288-297. [PMID: 30009767 DOI: 10.1016/j.bcp.2018.07.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 07/11/2018] [Indexed: 11/17/2022]
Abstract
The ribbon isomer of α-conotoxin AuIB has 10-fold greater potency than the wild-type globular isomer at inhibiting nicotinic acetylcholine receptors (nAChRs) in rat parasympathetic neurons, and unlike its globular isoform, ribbon AuIB only targets a specific stoichiometry of the α3β4 nAChR subtype. Previous electrophysiological recordings of AuIB indicated that ribbon AuIB binds to the α3(+)α3(-) interface within the nAChR extracellular domain, which is displayed by the (α3)3(β4)2 stoichiometry but not by (α3)2(β4)3. This specificity for a particular stoichiometry is remarkable and suggests that ribbon isoforms of α-conotoxins might have great potential in drug design. In this study, we investigated the binding mode and structure-activity relationships of ribbon AuIB using a combination of molecular modeling and electrophysiology recording to determine the features that underpin its selectivity. An alanine scan showed that positions 4 and 9 of ribbon AuIB are the main determinants of the interaction with (α3)3(β4)2 nAChR. Our computational models indicate that the first loop of ribbon AuIB binds in the "aromatic box" of the acetylcholine orthosteric binding site, similar to that of globular AuIB. In contrast, the second loop and the termini of the ribbon isomer have different orientations and interactions in the binding sites to those of the globular isomer. The structure-activity relationships reported herein should be useful to design peptides displaying a ribbon α-conotoxin scaffold for inhibition of nAChR subtypes that have hitherto been difficult to selectively target.
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Affiliation(s)
- Xiaosa Wu
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Han-Shen Tae
- Illawarra Health and Medical Research Institute (IHMRI), The University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Yen-Hua Huang
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - David J Adams
- Illawarra Health and Medical Research Institute (IHMRI), The University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - David J Craik
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Quentin Kaas
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
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13
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Ayan M, Essiz S. The neural γ 2α 1β 2α 1β 2 gamma amino butyric acid ion channel receptor: structural analysis of the effects of the ivermectin molecule and disulfide bridges. J Mol Model 2018; 24:206. [PMID: 30008086 DOI: 10.1007/s00894-018-3739-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 06/27/2018] [Indexed: 12/21/2022]
Abstract
While ~30% of the human genome encodes membrane proteins, only a handful of structures of membrane proteins have been resolved to high resolution. Here, we studied the structure of a member of the Cys-loop ligand gated ion channel protein superfamily of receptors, human type A γ2α1β2α1β2 gamma amino butyric acid receptor complex in a lipid bilayer environment. Studying the correlation between the structure and function of the gamma amino butyric acid receptor may enhance our understanding of the molecular basis of ion channel dysfunctions linked with epilepsy, ataxia, migraine, schizophrenia and other neurodegenerative diseases. The structure of human γ2α1β2α1β2 has been modeled based on the X-ray structure of the Caenorhabditis elegans glutamate-gated chloride channel via homology modeling. The template provided the first inhibitory channel structure for the Cys-loop superfamily of ligand-gated ion channels. The only available template structure before this glutamate-gated chloride channel was a cation selective channel which had very low sequence identity with gamma aminobutyric acid receptor. Here, our aim was to study the effect of structural corrections originating from modeling on a more reliable template structure. The homology model was analyzed for structural properties via a 100 ns molecular dynamics (MD) study. Due to the structural shifts and the removal of an open channel potentiator molecule, ivermectin, from the template structure, helical packing changes were observed in the transmembrane segment. Namely removal of ivermectin molecule caused a closure around the Leu 9 position along the ion channel. In terms of the structural shifts, there are three potential disulfide bridges between the M1 and M3 helices of the γ2 and 2 α1 subunits in the model. The effect of these disulfide bridges was investigated via monitoring the differences in root mean square fluctuations (RMSF) of individual amino acids and principal component analysis of the MD trajectory of the two homology models-one with the disulfide bridge and one with protonated Cys residues. In all subunit types, RMSF of the transmembrane domain helices are reduced in the presence of disulfide bridges. Additionally, loop A, loop F and loop C fluctuations were affected in the extracellular domain. In cross-correlation analysis of the trajectory, the two model structures displayed different coupling in between the M2-M3 linker region, protruding from the membrane, and the β1-β2/D loop and cys-loop regions in the extracellular domain. Correlations of the C loop, which collapses directly over the bound ligand molecule, were also affected by differences in the packing of transmembrane helices. Finally, more localized correlations were observed in the transmembrane helices when disulfide bridges were present in the model. The differences observed in this study suggest that dynamic coupling at the interface of extracellular and ion channel domains differs from the coupling introduced by disulfide bridges in the transmembrane region. We hope that this hypothesis will be tested experimentally in the near future.
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Affiliation(s)
- Meral Ayan
- Bioinformatics and Genetics Department, Faculty of Engineering and Natural Sciences, Kadir Has University, 34083, Fatih, Istanbul, Turkey
| | - Sebnem Essiz
- Bioinformatics and Genetics Department, Faculty of Engineering and Natural Sciences, Kadir Has University, 34083, Fatih, Istanbul, Turkey.
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New K, Del Villar SG, Mazzaferro S, Alcaino C, Bermudez I. The fifth subunit of the (α4β2) 2 β2 nicotinic ACh receptor modulates maximal ACh responses. Br J Pharmacol 2018; 175:1822-1837. [PMID: 28600847 PMCID: PMC5978951 DOI: 10.1111/bph.13905] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 05/16/2017] [Accepted: 06/05/2017] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE The fifth subunit in the (α4β2)2 α4 nicotinic ACh receptor (nAChR) plays a determining role in the pharmacology of this nAChR type. Here, we have examined the role of the fifth subunit in the ACh responses of the (α4β2)2 β2 nAChR type. EXPERIMENTAL APPROACH The role of the fifth subunit in receptor function was explored using two-electrode voltage clamp electrophysiology, along with subunit-targeted mutagenesis and the substituted cysteine scanning method applied to fully linked (α4β2)2 β2 receptors. KEY RESULTS Covalent modification of the cysteine-substituted fifth subunit with a thiol-reactive agent (MTS) caused irreversible inhibition of receptor function. ACh reduced the rate of the reaction to MTS, but the competitive inhibitor dihydro-β-erythroidine had no effect. Alanine substitution of conserved residues that line the core of the agonist sites on α4(+)/β2(-) interfaces did not impair receptor function. However, impairment of agonist binding to α4(+)/β2(-) agonist sites by mutagenesis modified the effect of ACh on the rate of the reaction to MTS. The extent of this effect was dependent on the position of the agonist site relative to the fifth subunit. CONCLUSIONS AND IMPLICATIONS The fifth subunit in the (α4β2)2 β2 receptor isoform modulates maximal ACh responses. This effect appears to be driven by a modulatory, and asymmetric, association with the α4(+)/β2(-) agonist sites. LINKED ARTICLES This article is part of a themed section on Nicotinic Acetylcholine Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.11/issuetoc.
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Affiliation(s)
- Karina New
- Department of Biological and Medical Sciences, Faculty of Health and Life SciencesOxford Brookes UniversityOxfordUK
| | - Silvia Garcia Del Villar
- Department of Biological and Medical Sciences, Faculty of Health and Life SciencesOxford Brookes UniversityOxfordUK
| | - Simone Mazzaferro
- Department of Biological and Medical Sciences, Faculty of Health and Life SciencesOxford Brookes UniversityOxfordUK
| | - Constanza Alcaino
- Department of Biological and Medical Sciences, Faculty of Health and Life SciencesOxford Brookes UniversityOxfordUK
| | - Isabel Bermudez
- Department of Biological and Medical Sciences, Faculty of Health and Life SciencesOxford Brookes UniversityOxfordUK
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15
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Crestey F, Jensen AA, Soerensen C, Magnus CB, Andreasen JT, Peters GHJ, Kristensen JL. Dual Nicotinic Acetylcholine Receptor α4β2 Antagonists/α7 Agonists: Synthesis, Docking Studies, and Pharmacological Evaluation of Tetrahydroisoquinolines and Tetrahydroisoquinolinium Salts. J Med Chem 2018; 61:1719-1729. [DOI: 10.1021/acs.jmedchem.7b01895] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- François Crestey
- Department
of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Anders A. Jensen
- Department
of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Christian Soerensen
- Department
of Chemistry, Technical University of Denmark, Kemitorvet 207, 2800 Kongens Lyngby, Denmark
| | - Charlotte Busk Magnus
- Department
of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
- Department
of Chemistry, Technical University of Denmark, Kemitorvet 207, 2800 Kongens Lyngby, Denmark
| | - Jesper T. Andreasen
- Department
of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Günther H. J. Peters
- Department
of Chemistry, Technical University of Denmark, Kemitorvet 207, 2800 Kongens Lyngby, Denmark
| | - Jesper L. Kristensen
- Department
of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
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16
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Shimokawa J. Synthetic Studies on Heteropolycyclic Natural Products: Development of Divergent Strategy. Chem Pharm Bull (Tokyo) 2018; 66:105-115. [DOI: 10.1248/cpb.c17-00819] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Jun Shimokawa
- Graduate School of Pharmaceutical Sciences, Nagoya University
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17
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Ma Q, Tae HS, Wu G, Jiang T, Yu R. Exploring the Relationship between Nicotinic Acetylcholine Receptor Ligand Size, Efficiency, Efficacy, and C-Loop Opening. J Chem Inf Model 2017; 57:1947-1956. [PMID: 28718646 DOI: 10.1021/acs.jcim.7b00152] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels mediating fundamental physiological activities in the nervous system and have become important targets for drug design. For a long time, the acetylcholine binding protein (AChBP) has been used as a surrogate to study the nAChR structure-function. Taking advantage of more than 100 AChBP crystal structures in the Protein DataBank (PDB), we explored the relationship between the size, efficiency, and efficacy of nAChR ligands and the C-loop movement. We found that the size of the ligand is correlated with the opening of the C-loop, which can be used in selecting AChBP crystal structures with appropriate C-loop opening to be used for nAChR ligand docking. Ligand size and C-loop opening are reversely correlated with the ligand efficiency rather than the binding affinity. Ligand efficiency could be accurately predicted using simple computational docking, giving a correlation coefficients (R2) up to 0.73. The efficacy of nAChR ligands might be related to ligand size, C-loop opening, and ligand efficiency. Results from this study are useful for engineering the binding affinity and efficacy of nAChR ligands.
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Affiliation(s)
- Qianyun Ma
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China , Qingdao 266003, China.,Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology , Qingdao 266003, China
| | - Han-Shen Tae
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong , Wollongong, New South Wales 2522, Australia
| | - Guanzhao Wu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China , Qingdao 266003, China.,Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology , Qingdao 266003, China
| | - Tao Jiang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China , Qingdao 266003, China.,Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology , Qingdao 266003, China
| | - Rilei Yu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China , Qingdao 266003, China.,Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology , Qingdao 266003, China
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18
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Giastas P, Zouridakis M, Tzartos SJ. Understanding structure-function relationships of the human neuronal acetylcholine receptor: insights from the first crystal structures of neuronal subunits. Br J Pharmacol 2017; 175:1880-1891. [PMID: 28452148 DOI: 10.1111/bph.13838] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 04/13/2017] [Accepted: 04/20/2017] [Indexed: 01/27/2023] Open
Abstract
Nicotinic ACh receptors (nAChRs) are the best studied members of the superfamily of pentameric ligand-gated ion channels (pLGICs). Neuronal nAChRs regulate neuronal excitability and neurotransmitter release in the nervous system and form either homo- or hetero-pentameric complexes with various combinations of the 11 neuronal nAChR subunits (α2-7, α9, α10 and β2-4) known to exist in humans. In addition to their wide distribution in the nervous system, neuronal nAChRs have been also found in immune cells and many peripheral tissues. These nAChRs are important drug targets for neurological and neuropsychiatric diseases (e.g. Alzheimer's, schizophrenia) and substance addiction (e.g. nicotine), as well as in a variety of diseases such as chronic pain, auditory disorders and some cancers. To decipher the functional mechanisms of human nAChRs and develop efficient and specific therapeutic drugs, elucidation of their high-resolution structures is needed. Recent studies, including the X-ray crystal structures of the near-intact α4β2 nAChR and of the ligand-binding domains of the α9 and α2 subunits, have advanced our knowledge on the detailed structure of the ligand-binding sites formed between the same and different subunits and revealed many other functionally important interactions. The aim of this review is to highlight some of the structural and functional findings of these studies and to compare them with recent breakthrough findings on other pLGIC members and earlier data from their homologous ACh-binding proteins. LINKED ARTICLES This article is part of a themed section on Nicotinic Acetylcholine Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.11/issuetoc.
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Affiliation(s)
- Petros Giastas
- Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece
| | - Marios Zouridakis
- Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece
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19
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Jepsen TH, Glibstrup E, Crestey F, Jensen AA, Kristensen JL. A strategic approach to [6,6]-bicyclic lactones: application towards the CD fragment of DHβE. Beilstein J Org Chem 2017; 13:988-994. [PMID: 28684978 PMCID: PMC5480346 DOI: 10.3762/bjoc.13.98] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 05/11/2017] [Indexed: 12/19/2022] Open
Abstract
We report an effective synthetic protocol to access [6,6]-bicyclic lactone moieties through a regio- and stereoselective intramolecular Mizoroki–Heck cross-coupling reaction followed by a 6π-electrocyclization. This method enabled the first synthesis of the elusive CD fragment of the Erythrina alkaloid DHβE. Preliminary pharmacological evaluations support the notion that the key pharmacophores of DHβE are located in the A and B rings.
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Affiliation(s)
- Tue Heesgaard Jepsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Emil Glibstrup
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - François Crestey
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Anders A Jensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Jesper Langgaard Kristensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
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20
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Abraham N, Paul B, Ragnarsson L, Lewis RJ. Escherichia coli Protein Expression System for Acetylcholine Binding Proteins (AChBPs). PLoS One 2016; 11:e0157363. [PMID: 27304486 PMCID: PMC4909209 DOI: 10.1371/journal.pone.0157363] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 05/27/2016] [Indexed: 01/22/2023] Open
Abstract
Nicotinic acetylcholine receptors (nAChR) are ligand gated ion channels, identified as therapeutic targets for a range of human diseases. Drug design for nAChR related disorders is increasingly using structure-based approaches. Many of these structural insights for therapeutic lead development have been obtained from co-crystal structures of nAChR agonists and antagonists with the acetylcholine binding protein (AChBP). AChBP is a water soluble, structural and functional homolog of the extracellular, ligand-binding domain of nAChRs. Currently, AChBPs are recombinantly expressed in eukaryotic expression systems for structural and biophysical studies. Here, we report the establishment of an Escherichia coli (E. coli) expression system that significantly reduces the cost and time of production compared to the existing expression systems. E. coli can efficiently express unglycosylated AChBP for crystallography and makes the expression of isotopically labelled forms feasible for NMR. We used a pHUE vector containing an N-terminal His-tagged ubiquitin fusion protein to facilitate AChBP expression in the soluble fractions, and thus avoid the need to recover protein from inclusion bodies. The purified protein yield obtained from the E. coli expression system is comparable to that obtained from existing AChBP expression systems. E. coli expressed AChBP bound nAChR agonists and antagonists with affinities matching those previously reported. Thus, the E. coli expression system significantly simplifies the expression and purification of functional AChBP for structural and biophysical studies.
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Affiliation(s)
- Nikita Abraham
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, Australia
| | - Blessy Paul
- Division of Molecular Cell Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, Australia
| | - Lotten Ragnarsson
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, Australia
| | - Richard J. Lewis
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, Australia
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21
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Umihara H, Yoshino T, Shimokawa J, Kitamura M, Fukuyama T. Development of a Divergent Synthetic Route to the Erythrina Alkaloids: Asymmetric Syntheses of 8-Oxo-erythrinine, Crystamidine, 8-Oxo-erythraline, and Erythraline. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201602650] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Hirotatsu Umihara
- Graduate School of Pharmaceutical Sciences; University of Tokyo; 7-3-1 Hongo, Bunkyo-ku Tokyo 113-0033 Japan
| | - Tomomi Yoshino
- Graduate School of Pharmaceutical Sciences; Nagoya University; Furo-cho, Chikusa Nagoya, Aichi 464-8601 Japan
| | - Jun Shimokawa
- Graduate School of Pharmaceutical Sciences; Nagoya University; Furo-cho, Chikusa Nagoya, Aichi 464-8601 Japan
| | - Masato Kitamura
- Graduate School of Pharmaceutical Sciences; Nagoya University; Furo-cho, Chikusa Nagoya, Aichi 464-8601 Japan
| | - Tohru Fukuyama
- Graduate School of Pharmaceutical Sciences; Nagoya University; Furo-cho, Chikusa Nagoya, Aichi 464-8601 Japan
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22
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Umihara H, Yoshino T, Shimokawa J, Kitamura M, Fukuyama T. Development of a Divergent Synthetic Route to the Erythrina Alkaloids: Asymmetric Syntheses of 8-Oxo-erythrinine, Crystamidine, 8-Oxo-erythraline, and Erythraline. Angew Chem Int Ed Engl 2016; 55:6915-8. [DOI: 10.1002/anie.201602650] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Indexed: 02/06/2023]
Affiliation(s)
- Hirotatsu Umihara
- Graduate School of Pharmaceutical Sciences; University of Tokyo; 7-3-1 Hongo, Bunkyo-ku Tokyo 113-0033 Japan
| | - Tomomi Yoshino
- Graduate School of Pharmaceutical Sciences; Nagoya University; Furo-cho, Chikusa Nagoya, Aichi 464-8601 Japan
| | - Jun Shimokawa
- Graduate School of Pharmaceutical Sciences; Nagoya University; Furo-cho, Chikusa Nagoya, Aichi 464-8601 Japan
| | - Masato Kitamura
- Graduate School of Pharmaceutical Sciences; Nagoya University; Furo-cho, Chikusa Nagoya, Aichi 464-8601 Japan
| | - Tohru Fukuyama
- Graduate School of Pharmaceutical Sciences; Nagoya University; Furo-cho, Chikusa Nagoya, Aichi 464-8601 Japan
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23
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Banerjee J, Yongye AB, Chang YP, Gyanda R, Medina-Franco JL, Armishaw CJ. Design and synthesis of α-conotoxin GID analogues as selective α4β2 nicotinic acetylcholine receptor antagonists. Biopolymers 2016; 102:78-87. [PMID: 24122487 DOI: 10.1002/bip.22413] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 08/30/2013] [Accepted: 09/09/2013] [Indexed: 01/01/2023]
Abstract
The α4β2 nicotinic acetylcholine receptor (nAChR) is an important target for currently approved smoking cessation therapeutics. However, the development of highly selective α4β2 nAChR antagonists remains a significant challenge. α-Conotoxin GID is an antagonist of α4β2 nAChRs, though it is significantly more potent toward the α3β2 and α7 subtypes. With the goal of obtaining further insights into α-conotoxin GID/nAChR interactions that could lead to the design of GID analogues with improved affinity for α4β2 nAChRs, we built a homology model of the GID/α4β2 complex using an X-ray co-crystal structure of an α-conotoxin/acetylcholine binding protein (AChBP) complex. Several additional interactions that could potentially enhance the affinity of GID for α4β2 nAChRs were observed in our model, which led to the design and synthesis of 22 GID analogues. Seven analogues displayed inhibitory activity toward α4β2 nAChRs that was comparable to GID. Significantly, both GID[A10S] and GID[V13I] demonstrated moderately improved selectivity toward α4β2 over α3β2 when compared with GID, while GID[V18N] exhibited no measurable inhibitory activity for the α3β2 subtype, yet retained inhibitory activity for α4β2. In this regard, GID[V18N] is the most α4β2 nAChR selective α-conotoxin analogue identified to date.
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Affiliation(s)
- Jayati Banerjee
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, FL, 34987
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Abstract
In this issue of Structure, Bourne et al. (2015) report X-ray structures of acetylcholine binding protein with two fast-acting phycotoxins from the pinnatoxin family. The results may pave the way for development of new CNS-penetrant and subtype-selective nAChR antagonists.
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Affiliation(s)
- Azadeh Shahsavar
- Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark
| | - Thomas Balle
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia.
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Shahsavar A, Gajhede M, Kastrup JS, Balle T. Structural Studies of Nicotinic Acetylcholine Receptors: Using Acetylcholine-Binding Protein as a Structural Surrogate. Basic Clin Pharmacol Toxicol 2016; 118:399-407. [DOI: 10.1111/bcpt.12528] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 11/02/2015] [Indexed: 01/09/2023]
Affiliation(s)
- Azadeh Shahsavar
- Department of Molecular Biology and Genetics; Danish Research Institute of Translational Neuroscience - DANDRITE; Aarhus University; Aarhus Denmark
- Department of Drug Design and Pharmacology; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
| | - Michael Gajhede
- Department of Drug Design and Pharmacology; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
| | - Jette S. Kastrup
- Department of Drug Design and Pharmacology; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
| | - Thomas Balle
- Faculty of Pharmacy; The University of Sydney; Sydney NSW Australia
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26
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Jaikhan P, Boonyarat C, Arunrungvichian K, Taylor P, Vajragupta O. Design and Synthesis of Nicotinic Acetylcholine Receptor Antagonists and their Effect on Cognitive Impairment. Chem Biol Drug Des 2015; 87:39-56. [DOI: 10.1111/cbdd.12627] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 07/03/2015] [Accepted: 07/15/2015] [Indexed: 12/13/2022]
Affiliation(s)
- Pattaporn Jaikhan
- Center of Excellence for Innovation in Drug Design and Discovery; Faculty of Pharmacy; Mahidol University; 447 Sri-Ayudya Road Bangkok 10400 Thailand
| | - Chantana Boonyarat
- Department of Pharmaceutical Chemistry; Faculty of Pharmaceutical Science; KhonKaen University; KhonKaen 4000 Thailand
| | - Kuntarat Arunrungvichian
- Center of Excellence for Innovation in Drug Design and Discovery; Faculty of Pharmacy; Mahidol University; 447 Sri-Ayudya Road Bangkok 10400 Thailand
- Department of Pharmacology; Skaggs School of Pharmacy and Pharmaceutical Sciences; University of California; San Diego 9500 Gilman Drive La Jolla CA 92093-0657 USA
| | - Palmer Taylor
- Department of Pharmacology; Skaggs School of Pharmacy and Pharmaceutical Sciences; University of California; San Diego 9500 Gilman Drive La Jolla CA 92093-0657 USA
| | - Opa Vajragupta
- Center of Excellence for Innovation in Drug Design and Discovery; Faculty of Pharmacy; Mahidol University; 447 Sri-Ayudya Road Bangkok 10400 Thailand
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Chiodo L, Malliavin TE, Maragliano L, Cottone G, Ciccotti G. A Structural Model of the Human α7 Nicotinic Receptor in an Open Conformation. PLoS One 2015; 10:e0133011. [PMID: 26208301 PMCID: PMC4514475 DOI: 10.1371/journal.pone.0133011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 06/22/2015] [Indexed: 11/20/2022] Open
Abstract
Nicotinic acetylcholine receptors (nAchRs) are ligand-gated ion channels that regulate chemical transmission at the neuromuscular junction. Structural information is available at low resolution from open and closed forms of an eukaryotic receptor, and at high resolution from other members of the same structural family, two prokaryotic orthologs and an eukaryotic GluCl channel. Structures of human channels however are still lacking. Homology modeling and Molecular Dynamics simulations are valuable tools to predict structures of unknown proteins, however, for the case of human nAchRs, they have been unsuccessful in providing a stable open structure so far. This is due to different problems with the template structures: on one side the homology with prokaryotic species is too low, while on the other the open eukaryotic GluCl proved itself unstable in several MD studies and collapsed to a dehydrated, non-conductive conformation, even when bound to an agonist. Aim of this work is to obtain, by a mixing of state-of-the-art homology and simulation techniques, a plausible prediction of the structure (still unknown) of the open state of human α7 nAChR complexed with epibatidine, from which it is possible to start structural and functional test studies. To prevent channel closure we employ a restraint that keeps the transmembrane pore open, and obtain in this way a stable, hydrated conformation. To further validate this conformation, we run four long, unbiased simulations starting from configurations chosen at random along the restrained trajectory. The channel remains stable and hydrated over the whole runs. This allows to assess the stability of the putative open conformation over a cumulative time of 1 μs, 800 ns of which are of unbiased simulation. Mostly based on the analysis of pore hydration and size, we suggest that the obtained structure has reasonable chances to be (at least one of the possible) structures of the channel in the open conformation.
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Affiliation(s)
- Letizia Chiodo
- Center for Life Nano Science @Sapienza, Istituto Italiano di Tecnologia, Rome, Italy
| | - Thérèse E. Malliavin
- Institut Pasteur and CNRS UMR 3528, Unité de Bioinformatique Structurale, Paris, France
| | - Luca Maragliano
- Center for Synaptic Neuroscience, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Grazia Cottone
- Department of Physics and Chemistry, University of Palermo, Palermo, Italy
- School of Physics, University College Dublin, Dublin, Ireland
| | - Giovanni Ciccotti
- School of Physics, University College Dublin, Dublin, Ireland
- Department of Physics, University of Roma “La Sapienza”, Rome, Italy
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Shahsavar A, Ahring PK, Olsen JA, Krintel C, Kastrup JS, Balle T, Gajhede M. Acetylcholine-Binding Protein Engineered to Mimic the α4-α4 Binding Pocket in α4β2 Nicotinic Acetylcholine Receptors Reveals Interface Specific Interactions Important for Binding and Activity. Mol Pharmacol 2015; 88:697-707. [DOI: 10.1124/mol.115.098061] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 07/15/2015] [Indexed: 12/23/2022] Open
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Morton RA, Baptista-Hon DT, Hales TG, Lovinger DM. Agonist- and antagonist-induced up-regulation of surface 5-HT3 A receptors. Br J Pharmacol 2015; 172:4066-77. [PMID: 25989383 DOI: 10.1111/bph.13197] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 03/25/2015] [Accepted: 05/06/2015] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND AND PURPOSE The 5-HT3 receptor is a member of the pentameric ligand-gated ion channel family and is pharmacologically targeted to treat irritable bowel syndrome and nausea/emesis. Furthermore, many antidepressants elevate extracellular concentrations of 5-HT. This study investigates the functional consequences of exposure of recombinant 5-HT3 A receptors to agonists and antagonists. EXPERIMENTAL APPROACH We used HEK cells stably expressing recombinant 5-HT3 A receptors and the ND7/23 (mouse neuroblastoma/dorsal root ganglion hybrid) cell line, which expresses endogenous 5-HT3 receptors. Surface expression of recombinant 5-HT3 A receptors, modified to contain the bungarotoxin (BTX) binding sequence, was quantified using fluorescence microscopy to image BTX-conjugated fluorophores. Whole cell voltage-clamp electrophysiology was used to measure the density of current mediated by 5-HT3 A receptors. KEY RESULTS 5-HT3 A receptors were up-regulated by the prolonged presence of agonists (5-HT and m-chlorophenylbiguanide) and antagonists (MDL-72222 and morphine). The up-regulation of 5-HT3 A receptors by 5-HT and MDL-72222 was time- and concentration-dependent but was independent of newly translated receptors. The phenomenon was observed for recombinant rodent and human 5-HT3 A receptors and for endogenous 5-HT3 receptors in neuronal ND7/23 cells. CONCLUSIONS AND IMPLICATIONS Up-regulation of 5-HT3 A receptors, following exposure to either agonists or antagonists suggests that this phenomenon may occur in response to different therapeutic agents. Medications that elevate 5-HT levels, such as the antidepressant inhibitors of 5-HT reuptake and antiemetic inhibitors of 5-HT3 receptor function, may both raise receptor expression. However, this will require further investigation in vivo.
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Affiliation(s)
- Russell A Morton
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD, USA.,Department of Pharmacology and Physiology, George Washington University, Washington, DC, USA
| | - Daniel T Baptista-Hon
- Institute of Academic Anaesthesia, Division of Neuroscience, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - Tim G Hales
- Department of Pharmacology and Physiology, George Washington University, Washington, DC, USA.,Institute of Academic Anaesthesia, Division of Neuroscience, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - David M Lovinger
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD, USA.,Department of Pharmacology and Physiology, George Washington University, Washington, DC, USA
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Jepsen TH, Jensen AA, Lund MH, Glibstrup E, Kristensen JL. Synthesis and Pharmacological Evaluation of DHβE Analogues as Neuronal Nicotinic Acetylcholine Receptor Antagonists. ACS Med Chem Lett 2014; 5:766-70. [PMID: 25050162 DOI: 10.1021/ml500094c] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 05/20/2014] [Indexed: 11/29/2022] Open
Abstract
Dihydro-β-erythroidine (DHβE) is a member of the Erythrina family of alkaloids and a potent competitive antagonist of the α4β2-subtype of the nicotinic acetylcholine receptors (nAChRs). Guided by an X-ray structure of DHβE in complex with an ACh binding protein, we detail the design, synthesis, and pharmacological characterization of a series of DHβE analogues in which two of the four rings in the natural product has been excluded. We found that the direct analogue of DHβE maintains affinity for the α4β2-subtype, but further modifications of the simplified analogues were detrimental to their activities on the nAChRs.
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Affiliation(s)
- Tue Heesgaard Jepsen
- Department of Drug Design
and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Anders A. Jensen
- Department of Drug Design
and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Mads Henrik Lund
- Department of Drug Design
and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Emil Glibstrup
- Department of Drug Design
and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Jesper Langgaard Kristensen
- Department of Drug Design
and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
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Structural basis for cooperative interactions of substituted 2-aminopyrimidines with the acetylcholine binding protein. Proc Natl Acad Sci U S A 2014; 111:10749-54. [PMID: 25006260 DOI: 10.1073/pnas.1410992111] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The nicotinic acetylcholine receptor (nAChR) and the acetylcholine binding protein (AChBP) are pentameric oligomers in which binding sites for nicotinic agonists and competitive antagonists are found at selected subunit interfaces. The nAChR spontaneously exists in multiple conformations associated with its activation and desensitization steps, and conformations are selectively stabilized by binding of agonists and antagonists. In the nAChR, agonist binding and the associated conformational changes accompanying activation and desensitization are cooperative. AChBP, which lacks the transmembrane spanning and cytoplasmic domains, serves as a homology model of the extracellular domain of the nAChRs. We identified unique cooperative binding behavior of a number of 4,6-disubstituted 2-aminopyrimidines to Lymnaea AChBP, with different molecular variants exhibiting positive, nH > 1.0, and negative cooperativity, nH < 1.0. Therefore, for a distinctive set of ligands, the extracellular domain of a nAChR surrogate suffices to accommodate cooperative interactions. X-ray crystal structures of AChBP complexes with examples of each allowed the identification of structural features in the ligands that confer differences in cooperative behavior. Both sets of molecules bind at the agonist-antagonist site, as expected from their competition with epibatidine. An analysis of AChBP quaternary structure shows that cooperative ligand binding is associated with a blooming or flare conformation, a structural change not observed with the classical, noncooperative, nicotinic ligands. Positively and negatively cooperative ligands exhibited unique features in the detailed binding determinants and poses of the complexes.
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Olsen JA, Ahring PK, Kastrup JS, Gajhede M, Balle T. Structural and functional studies of the modulator NS9283 reveal agonist-like mechanism of action at α4β2 nicotinic acetylcholine receptors. J Biol Chem 2014; 289:24911-21. [PMID: 24982426 DOI: 10.1074/jbc.m114.568097] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Modulation of Cys loop receptor ion channels is a proven drug discovery strategy, but many underlying mechanisms of the mode of action are poorly understood. We report the x-ray structure of the acetylcholine-binding protein from Lymnaea stagnalis with NS9283, a stoichiometry selective positive modulator that targets the α4-α4 interface of α4β2 nicotinic acetylcholine receptors (nAChRs). Together with homology modeling, mutational data, quantum mechanical calculations, and pharmacological studies on α4β2 nAChRs, the structure reveals a modulator binding mode that overlaps the α4-α4 interface agonist (acetylcholine)-binding site. Analysis of contacts to residues known to govern agonist binding and function suggests that modulation occurs by an agonist-like mechanism. Selectivity for α4-α4 over α4-β2 interfaces is determined mainly by steric restrictions from Val-136 on the β2-subunit and favorable interactions between NS9283 and His-142 at the complementary side of α4. In the concentration ranges where modulation is observed, its selectivity prevents NS9283 from directly activating nAChRs because activation requires coordinated action from more than one interface. However, we demonstrate that in a mutant receptor with one natural and two engineered α4-α4 interfaces, NS9283 is an agonist. Modulation via extracellular binding sites is well known for benzodiazepines acting at γ-aminobutyric acid type A receptors. Like NS9283, benzodiazepines increase the apparent agonist potency with a minimal effect on efficacy. The shared modulatory profile along with a binding site located in an extracellular subunit interface suggest that modulation via an agonist-like mechanism may be a common mechanism of action that potentially could apply to Cys loop receptors beyond the α4β2 nAChRs.
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Affiliation(s)
- Jeppe A Olsen
- From NeuroSearch A/S, Pederstrupvej 93, 2750 Ballerup, Denmark, the Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark, the Faculty of Pharmacy, The University of Sydney, Sydney, New South Wales 2006, Australia, and
| | - Philip K Ahring
- the Faculty of Pharmacy, The University of Sydney, Sydney, New South Wales 2006, Australia, and Saniona AB, Baltorpvej 54, 2750 Ballerup, Denmark
| | - Jette S Kastrup
- the Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Michael Gajhede
- the Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Thomas Balle
- the Faculty of Pharmacy, The University of Sydney, Sydney, New South Wales 2006, Australia, and
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Kudryavtsev D, Makarieva T, Utkina N, Santalova E, Kryukova E, Methfessel C, Tsetlin V, Stonik V, Kasheverov I. Marine natural products acting on the acetylcholine-binding protein and nicotinic receptors: from computer modeling to binding studies and electrophysiology. Mar Drugs 2014; 12:1859-75. [PMID: 24686559 PMCID: PMC4012456 DOI: 10.3390/md12041859] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/20/2014] [Accepted: 03/11/2014] [Indexed: 12/29/2022] Open
Abstract
For a small library of natural products from marine sponges and ascidians, in silico docking to the Lymnaea stagnalis acetylcholine-binding protein (AChBP), a model for the ligand-binding domains of nicotinic acetylcholine receptors (nAChRs), was carried out and the possibility of complex formation was revealed. It was further experimentally confirmed via competition with radioiodinated α-bungarotoxin ([¹²⁵I]-αBgt) for binding to AChBP of the majority of analyzed compounds. Alkaloids pibocin, varacin and makaluvamines С and G had relatively high affinities (K(i) 0.5-1.3 μM). With the muscle-type nAChR from Torpedo californica ray and human neuronal α7 nAChR, heterologously expressed in the GH4C1 cell line, no competition with [¹²⁵I]-αBgt was detected in four compounds, while the rest showed an inhibition. Makaluvamines (K(i) ~ 1.5 μM) were the most active compounds, but only makaluvamine G and crambescidine 359 revealed a weak selectivity towards muscle-type nAChR. Rhizochalin, aglycone of rhizochalin, pibocin, makaluvamine G, monanchocidin, crambescidine 359 and aaptamine showed inhibitory activities in electrophysiology experiments on the mouse muscle and human α7 nAChRs, expressed in Xenopus laevis oocytes. Thus, our results confirm the utility of the modeling studies on AChBPs in a search for natural compounds with cholinergic activity and demonstrate the presence of the latter in the analyzed marine biological sources.
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Affiliation(s)
- Denis Kudryavtsev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street, 16/10, Moscow 117997, Russia.
| | - Tatyana Makarieva
- Elyakov Pacific Institute of Bioorganic Chemistry (PIBOC), Russian Academy of Sciences, Prospect 100 let Vladivostoku, 159, Vladivostok 690022, Russia.
| | - Natalia Utkina
- Elyakov Pacific Institute of Bioorganic Chemistry (PIBOC), Russian Academy of Sciences, Prospect 100 let Vladivostoku, 159, Vladivostok 690022, Russia.
| | - Elena Santalova
- Elyakov Pacific Institute of Bioorganic Chemistry (PIBOC), Russian Academy of Sciences, Prospect 100 let Vladivostoku, 159, Vladivostok 690022, Russia.
| | - Elena Kryukova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street, 16/10, Moscow 117997, Russia.
| | | | - Victor Tsetlin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street, 16/10, Moscow 117997, Russia.
| | - Valentin Stonik
- Elyakov Pacific Institute of Bioorganic Chemistry (PIBOC), Russian Academy of Sciences, Prospect 100 let Vladivostoku, 159, Vladivostok 690022, Russia.
| | - Igor Kasheverov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street, 16/10, Moscow 117997, Russia.
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Mohammad Hosseini Naveh Z, Malliavin TE, Maragliano L, Cottone G, Ciccotti G. Conformational changes in acetylcholine binding protein investigated by temperature accelerated molecular dynamics. PLoS One 2014; 9:e88555. [PMID: 24551117 PMCID: PMC3923797 DOI: 10.1371/journal.pone.0088555] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 01/07/2014] [Indexed: 11/19/2022] Open
Abstract
Despite the large number of studies available on nicotinic acetylcholine receptors, a complete account of the mechanistic aspects of their gating transition in response to ligand binding still remains elusive. As a first step toward dissecting the transition mechanism by accelerated sampling techniques, we study the ligand-induced conformational changes of the acetylcholine binding protein (AChBP), a widely accepted model for the full receptor extracellular domain. Using unbiased Molecular Dynamics (MD) and Temperature Accelerated Molecular Dynamics (TAMD) simulations we investigate the AChBP transition between the apo and the agonist-bound state. In long standard MD simulations, both conformations of the native protein are stable, while the agonist-bound structure evolves toward the apo one if the orientation of few key sidechains in the orthosteric cavity is modified. Conversely, TAMD simulations initiated from the native conformations are able to produce the spontaneous transition. With respect to the modified conformations, TAMD accelerates the transition by at least a factor 10. The analysis of some specific residue-residue interactions points out that the transition mechanism is based on the disruption/formation of few key hydrogen bonds. Finally, while early events of ligand dissociation are observed already in standard MD, TAMD accelerates the ligand detachment and, at the highest TAMD effective temperature, it is able to produce a complete dissociation path in one AChBP subunit.
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Affiliation(s)
| | - Therese E. Malliavin
- Institut Pasteur and CNRS UMR 3528, Unité de Bioinformatique Structurale, Paris, France
| | - Luca Maragliano
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Grazia Cottone
- School of Physics, University College Dublin, Dublin, Ireland
- Department of Physics and Chemistry, University of Palermo, Palermo, Italy
- * E-mail:
| | - Giovanni Ciccotti
- School of Physics, University College Dublin, Dublin, Ireland
- Department of Physics, University of Roma “La Sapienza”, Rome, Italy
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35
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Crestey F, Jensen AA, Borch M, Andreasen JT, Andersen J, Balle T, Kristensen JL. Design, Synthesis, and Biological Evaluation of Erythrina Alkaloid Analogues as Neuronal Nicotinic Acetylcholine Receptor Antagonists. J Med Chem 2013; 56:9673-82. [DOI: 10.1021/jm4013592] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- François Crestey
- Department
of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Anders A. Jensen
- Department
of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Morten Borch
- Department
of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Jesper Tobias Andreasen
- Department
of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Jacob Andersen
- Department
of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Thomas Balle
- Faculty
of Pharmacy, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Jesper Langgaard Kristensen
- Department
of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
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36
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Nys M, Kesters D, Ulens C. Structural insights into Cys-loop receptor function and ligand recognition. Biochem Pharmacol 2013; 86:1042-53. [DOI: 10.1016/j.bcp.2013.07.001] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 07/03/2013] [Accepted: 07/03/2013] [Indexed: 11/28/2022]
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37
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Jadey S, Purohit P, Auerbach A. Action of nicotine and analogs on acetylcholine receptors having mutations of transmitter-binding site residue αG153. ACTA ACUST UNITED AC 2013; 141:95-104. [PMID: 23277476 PMCID: PMC3536520 DOI: 10.1085/jgp.201210896] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A primary target for nicotine is the acetylcholine receptor channel (AChR). Some of the ability of nicotine to activate differentially AChR subtypes has been traced to a transmitter-binding site amino acid that is glycine in lower affinity and lysine in higher affinity AChRs. We studied the effects of mutations of this residue (αG153) in neuromuscular AChRs activated by nicotine and eight other agonists including nornicotine and anabasine. All of the mutations increased the unliganded gating equilibrium constant. The affinity of the resting receptor (Kd) and the net binding energy from the agonist for gating (ΔGB) were estimated by cross-concentration fitting of single-channel currents. In all but one of the agonist/mutant combinations there was a moderate decrease in Kd and essentially no change in ΔGB. The exceptional case was nicotine plus lysine, which showed a large, >8,000-fold decrease in Kd but no change in ΔGB. The extraordinary specificity of this combination leads us to speculate that AChRs with a lysine at position αG153 may be exposed to a nicotine-like compound in vivo.
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Affiliation(s)
- Snehal Jadey
- Department of Physiology and Biophysics, State University of New York, Buffalo, NY 14214, USA
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38
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Ursby T, Unge J, Appio R, Logan DT, Fredslund F, Svensson C, Larsson K, Labrador A, Thunnissen MMGM. The macromolecular crystallography beamline I911-3 at the MAX IV laboratory. JOURNAL OF SYNCHROTRON RADIATION 2013; 20:648-53. [PMID: 23765310 PMCID: PMC3943556 DOI: 10.1107/s0909049513011734] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 04/29/2013] [Indexed: 05/12/2023]
Abstract
The macromolecular crystallography beamline I911-3, part of the Cassiopeia/I911 suite of beamlines, is based on a superconducting wiggler at the MAX II ring of the MAX IV Laboratory in Lund, Sweden. The beamline is energy-tunable within a range between 6 and 18 keV. I911-3 opened for users in 2005. In 2010-2011 the experimental station was completely rebuilt and refurbished such that it has become a state-of-the-art experimental station with better possibilities for rapid throughput, crystal screening and work with smaller samples. This paper describes the complete I911-3 beamline and how it is embedded in the Cassiopeia suite of beamlines.
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Affiliation(s)
- Thomas Ursby
- MAX IV Laboratory, Lund University, POB 118, Lund SE-221 00, Sweden.
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39
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Ussing CA, Hansen CP, Petersen JG, Jensen AA, Rohde LAH, Ahring PK, Nielsen EØ, Kastrup JS, Gajhede M, Frølund B, Balle T. Synthesis, Pharmacology, and Biostructural Characterization of Novel α4β2 Nicotinic Acetylcholine Receptor Agonists. J Med Chem 2013; 56:940-51. [DOI: 10.1021/jm301409f] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Christine A. Ussing
- Department of Drug Design and
Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100
Copenhagen, Denmark
| | - Camilla P. Hansen
- Department of Drug Design and
Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100
Copenhagen, Denmark
| | - Jette G. Petersen
- Department of Drug Design and
Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100
Copenhagen, Denmark
| | - Anders A. Jensen
- Department of Drug Design and
Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100
Copenhagen, Denmark
| | - Line A. H. Rohde
- Department of Drug Design and
Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100
Copenhagen, Denmark
- NeuroSearch A/S, Pederstrupvej 93, DK-2750 Ballerup,
Denmark
| | | | | | - Jette S. Kastrup
- Department of Drug Design and
Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100
Copenhagen, Denmark
| | - Michael Gajhede
- Department of Drug Design and
Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100
Copenhagen, Denmark
| | - Bente Frølund
- Department of Drug Design and
Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100
Copenhagen, Denmark
| | - Thomas Balle
- Department of Drug Design and
Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100
Copenhagen, Denmark
- Faculty of Pharmacy, Building
A15, The University of Sydney, Sydney,
NSW 2006, Australia
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40
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Harpsøe K, Hald H, Timmermann DB, Jensen ML, Dyhring T, Nielsen EØ, Peters D, Balle T, Gajhede M, Kastrup JS, Ahring PK. Molecular determinants of subtype-selective efficacies of cytisine and the novel compound NS3861 at heteromeric nicotinic acetylcholine receptors. J Biol Chem 2012; 288:2559-70. [PMID: 23229547 DOI: 10.1074/jbc.m112.436337] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Deciphering which specific agonist-receptor interactions affect efficacy levels is of high importance, because this will ultimately aid in designing selective drugs. The novel compound NS3861 and cytisine are agonists of nicotinic acetylcholine receptors (nAChRs) and both bind with high affinity to heteromeric α3β4 and α4β2 nAChRs. However, initial data revealed that the activation patterns of the two compounds show very distinct maximal efficacy readouts at various heteromeric nAChRs. To investigate the molecular determinants behind these observations, we performed in-depth patch clamp electrophysiological measurements of efficacy levels at heteromeric combinations of α3- and α4-, with β2- and β4-subunits, and various chimeric constructs thereof. Compared with cytisine, which selectively activates receptors containing β4- but not β2-subunits, NS3861 displays the opposite β-subunit preference and a complete lack of activation at α4-containing receptors. The maximal efficacy of NS3861 appeared solely dependent on the nature of the ligand-binding domain, whereas efficacy of cytisine was additionally affected by the nature of the β-subunit transmembrane domain. Molecular docking to nAChR subtype homology models suggests agonist specific interactions to two different residues on the complementary subunits as responsible for the β-subunit preference of both compounds. Furthermore, a principal subunit serine to threonine substitution may explain the lack of NS3861 activation at α4-containing receptors. In conclusion, our results are consistent with a hypothesis where agonist interactions with the principal subunit (α) primarily determine binding affinity, whereas interactions with key amino acids at the complementary subunit (β) affect agonist efficacy.
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Affiliation(s)
- Kasper Harpsøe
- Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
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