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Graur A, Haymond A, Lee KH, Viscarra F, Russo P, Luchini A, Paige M, Bermudez-Diaz I, Kabbani N. Protein Painting Mass Spectrometry in the Discovery of Interaction Sites within the Acetylcholine Binding Protein. ACS Chem Neurosci 2024; 15:2322-2333. [PMID: 38804618 PMCID: PMC11157483 DOI: 10.1021/acschemneuro.4c00149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 05/13/2024] [Accepted: 05/14/2024] [Indexed: 05/29/2024] Open
Abstract
Nicotinic acetylcholine receptors (nAChRs) are a family of ligand-gated ion channel receptors that contribute to cognition, memory, and motor control in many organisms. The pharmacological targeting of these receptors, using small molecules or peptides, presents an important strategy for the development of drugs that can treat important human diseases, including neurodegenerative disorders. The Aplysia californica acetylcholine binding protein (Ac-AChBP) is a structural surrogate of the nAChR with high homology to the extracellular ligand binding domain of homopentameric nAChRs. In this study, we optimized protein-painting-based mass spectrometry to identify regions of interaction between the Ac-AChBP and several nAChR ligands. Using molecular dyes that adhere to the surface of a solubilized Ac-AChBP complex, we identified amino acid residues that constitute a contact site within the Ac-AChBP for α-bungarotoxin, choline, nicotine, and amyloid-β 1-42. By integrating innovation in protein painting mass spectrometry with computational structural modeling, we present a new experimental tool for analyzing protein interactions of the nAChR.
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Affiliation(s)
- Alexandru Graur
- School
of Systems Biology, George Mason University, Fairfax, Virginia 22030, United States
| | - Amanda Haymond
- Center
for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, Virginia 20110, United States
| | - Kyung Hyeon Lee
- Department
of Chemistry and Biochemistry, George Mason
University, Fairfax, Virginia 20110, United States
| | - Franco Viscarra
- Department
of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, United Kingdom
- Structural
Bioinformatics and Computational Biochemistry, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Paul Russo
- Center
for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, Virginia 20110, United States
| | - Alessandra Luchini
- Center
for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, Virginia 20110, United States
| | - Mikell Paige
- Department
of Chemistry and Biochemistry, George Mason
University, Fairfax, Virginia 20110, United States
| | - Isabel Bermudez-Diaz
- Department
of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, United Kingdom
| | - Nadine Kabbani
- School
of Systems Biology, George Mason University, Fairfax, Virginia 22030, United States
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Bourne Y, Sulzenbacher G, Chabaud L, Aráoz R, Radić Z, Conrod S, Taylor P, Guillou C, Molgó J, Marchot P. The Cyclic Imine Core Common to the Marine Macrocyclic Toxins Is Sufficient to Dictate Nicotinic Acetylcholine Receptor Antagonism. Mar Drugs 2024; 22:149. [PMID: 38667766 PMCID: PMC11050823 DOI: 10.3390/md22040149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 03/22/2024] [Accepted: 03/25/2024] [Indexed: 04/28/2024] Open
Abstract
Macrocyclic imine phycotoxins are an emerging class of chemical compounds associated with harmful algal blooms and shellfish toxicity. Earlier binding and electrophysiology experiments on nAChR subtypes and their soluble AChBP surrogates evidenced common trends for substantial antagonism, binding affinities, and receptor-subtype selectivity. Earlier, complementary crystal structures of AChBP complexes showed that common determinants within the binding nest at each subunit interface confer high-affinity toxin binding, while distinctive determinants from the flexible loop C, and either capping the nest or extending toward peripheral subsites, dictate broad versus narrow receptor subtype selectivity. From these data, small spiroimine enantiomers mimicking the functional core motif of phycotoxins were chemically synthesized and characterized. Voltage-clamp analyses involving three nAChR subtypes revealed preserved antagonism for both enantiomers, despite lower subtype specificity and binding affinities associated with faster reversibility compared with their macrocyclic relatives. Binding and structural analyses involving two AChBPs pointed to modest affinities and positional variability of the spiroimines, along with a range of AChBP loop-C conformations denoting a prevalence of antagonistic properties. These data highlight the major contribution of the spiroimine core to binding within the nAChR nest and confirm the need for an extended interaction network as established by the macrocyclic toxins to define high affinities and marked subtype specificity. This study identifies a minimal set of functional pharmacophores and binding determinants as templates for designing new antagonists targeting disease-associated nAChR subtypes.
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Affiliation(s)
- Yves Bourne
- Lab “Architecture et Fonction des Macromolécules Biologiques” (AFMB), Aix-Marseille Univ, CNRS, Faculté des Sciences Campus Luminy, 13288 Marseille cedex 09, France; (Y.B.); (G.S.)
| | - Gerlind Sulzenbacher
- Lab “Architecture et Fonction des Macromolécules Biologiques” (AFMB), Aix-Marseille Univ, CNRS, Faculté des Sciences Campus Luminy, 13288 Marseille cedex 09, France; (Y.B.); (G.S.)
| | - Laurent Chabaud
- Institut de Chimie des Substances Naturelles (ICSN), Univ Paris-Saclay, CNRS, 91198 Gif-sur-Yvette, France; (L.C.); (C.G.)
| | - Rómulo Aráoz
- Service d’Ingénierie Moléculaire pour la Santé (SIMoS) EMR CNRS 9004, Département Médicaments et Technologies pour la Santé, Institut des Sciences du Vivant Frédéric Joliot, CEA, INRAE, Université Paris-Saclay, 91191 Gif-sur-Yvette, France; (R.A.); (J.M.)
| | - Zoran Radić
- Skaggs School of Pharmacy and Pharmaceutical Sciences (SSPPS), University of California San Diego, La Jolla, CA 92093-0751, USA; (Z.R.); (P.T.)
| | - Sandrine Conrod
- Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille (CRN2M), Aix Marseille Univ, CNRS, 13344 Marseille, France;
| | - Palmer Taylor
- Skaggs School of Pharmacy and Pharmaceutical Sciences (SSPPS), University of California San Diego, La Jolla, CA 92093-0751, USA; (Z.R.); (P.T.)
| | - Catherine Guillou
- Institut de Chimie des Substances Naturelles (ICSN), Univ Paris-Saclay, CNRS, 91198 Gif-sur-Yvette, France; (L.C.); (C.G.)
| | - Jordi Molgó
- Service d’Ingénierie Moléculaire pour la Santé (SIMoS) EMR CNRS 9004, Département Médicaments et Technologies pour la Santé, Institut des Sciences du Vivant Frédéric Joliot, CEA, INRAE, Université Paris-Saclay, 91191 Gif-sur-Yvette, France; (R.A.); (J.M.)
| | - Pascale Marchot
- Lab “Architecture et Fonction des Macromolécules Biologiques” (AFMB), Aix-Marseille Univ, CNRS, Faculté des Sciences Campus Luminy, 13288 Marseille cedex 09, France; (Y.B.); (G.S.)
- Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille (CRN2M), Aix Marseille Univ, CNRS, 13344 Marseille, France;
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3
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Han Q, Zhou Y, Zi Y, Zhang R, Feng T, Zou R, Zhu W, Wang Y, Duan H. Discovery of piperonyl-tethered sulfoximines as novel low bee-toxicity aphicides targeting Amelα1/ratβ2 complex. Int J Biol Macromol 2023; 253:126719. [PMID: 37678680 DOI: 10.1016/j.ijbiomac.2023.126719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 08/18/2023] [Accepted: 09/03/2023] [Indexed: 09/09/2023]
Abstract
Nicotinic acetylcholine receptor (nAChR) is recognized as a significant insecticide target for neonicotinoids and some agonists. In this study, the nAChR α1 subunit from Apis mellifera was first found to be narrowly tuned to different bee toxicity insecticides, namely, sulfoxaflor (SFX) and flupyradifurone (FPF). Hence, novel sulfoximine derivatives 7a-h were rationally designed and synthesized by introducing a benzo[d][1,3]dioxole moiety into a unique sulfoximine skeleton based on the binding cavity characteristics of Amelα1/ratβ2. The two electrode voltage clamp responses of 7a-h were obviously lower than that of SFX, indicating their potentially low bee toxicity. Besides, representative compounds 7b and 7g exhibited low bee toxicity (LD50 > 11.0 μg/bee at 48 h) revealed by acute contact toxicity bioassays. Molecular modelling results indicated that Ile152, Ala151, and Val160 from honeybee subunit Amelα1 and Lys144 and Trp80 from aphid subunit Mpα1 may be crucial for bee toxicity and aphicidal activity, respectively. These results clarify the toxic mechanism of agonist insecticides on nontargeted pollinators and reveal novel scaffold sulfoximine aphicidal candidates with low bee toxicity. These results will provide a new perspective on the rational design and highly effective development of novel eco-friendly insecticides based on the structure of the nAChR subunit.
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Affiliation(s)
- Qing Han
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, People's Republic of China; Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, Beijing 100193, People's Republic of China
| | - Yuxin Zhou
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, Jilin 116000, People's Republic of China; Key Laboratory of Vegetation Ecology, MOE, Northeast Normal University, Changchun, Jilin 116000, People's Republic of China
| | - Yunjiang Zi
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, People's Republic of China; Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, Beijing 100193, People's Republic of China
| | - Rulei Zhang
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, People's Republic of China; Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, Beijing 100193, People's Republic of China
| | - Tianyu Feng
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, People's Republic of China; Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, Beijing 100193, People's Republic of China
| | - Renxuan Zou
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, People's Republic of China; Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, Beijing 100193, People's Republic of China
| | - Wenya Zhu
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, People's Republic of China; Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, Beijing 100193, People's Republic of China
| | - Yinliang Wang
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, Jilin 116000, People's Republic of China; Key Laboratory of Vegetation Ecology, MOE, Northeast Normal University, Changchun, Jilin 116000, People's Republic of China.
| | - Hongxia Duan
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, People's Republic of China; Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, Beijing 100193, People's Republic of China.
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Pant S, Nain S. Recent Advances in the Development of Pyrimidine-based CNS Agents. Curr Drug Discov Technol 2023; 20:14-28. [PMID: 36200187 DOI: 10.2174/1570163819666221003094402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 07/02/2022] [Accepted: 08/25/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND In the past few decades, considerable progress has been made in CNS drug discovery, and various new CNS agents have been developed. Pyrimidine is an important scaffold in the area of medicinal chemistry. Recently, pyrimidine-containing compounds have been successfully designed as potent CNS agents. Substantial research has been carried out on pyrimidine-bearing compounds to treat different disorders of CNS in various animal models. METHODS Utilizing various databases, including Google Scholar, PubMed, Science Direct, and Web of Science, the literature review was conducted. The specifics of significant articles were discussed with an emphasis on the potency of pyrimidines derivatives possessing CNS activity. RESULTS Recent papers indicating pyrimidine derivatives with CNS activity were incorporated into the manuscript. (46) to (50) papers included different pyrimidine derivatives as 5-HT agonist/antagonists, (62) to (67) as adenosine agonist/antagonist, (70) to (75) as anticonvulsant agents, (80) to (83) as cannabinoid receptor agonists, (102) to (103) as nicotinic and (110) as muscarinic receptor agonists. The remaining papers (113) to (114) represented pyrimidine-based molecular imaging agents. CONCLUSION Pyrimidine and its derivatives have been studied in detail to evaluate their efficacy in overcoming multiple central nervous system disorders. The article covers the current updates on pyrimidine-based compounds as potent CNS and molecular imaging agents and will definitely provide a better platform for the development of potent pyrimidine-based CNS drugs in the near future.
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Affiliation(s)
- Swati Pant
- Department of Pharmacy, Banasthali Vidyapith, Banasthali, Rajasthan, 304022, India
| | - Sumitra Nain
- Department of Pharmacy, Banasthali Vidyapith, Banasthali, Rajasthan, 304022, India
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5
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Stokes C, Camacho-Hernandez GA, Thakur GA, Wu X, Taylor P, Papke RL. Differential Activation and Desensitization States Promoted by Noncanonical α7 Nicotinic Acetylcholine Receptor Agonists. J Pharmacol Exp Ther 2022; 383:157-171. [PMID: 36279397 PMCID: PMC9553115 DOI: 10.1124/jpet.122.001354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 08/11/2022] [Indexed: 01/07/2023] Open
Abstract
A series of dipicolyl amine pyrimidines (DPPs) were previously identified as potential α7 agonists by means of a calcium influx assay in the presence of the positive allosteric modulator (PAM) 1-(5-chloro-2,4-dimethoxy-phenyl)-3-(5-methyl-isoxazol-3-yl)-urea (PNU-120596). The compounds lack the quaternary or strongly basic nitrogens of typical nicotinic agonists. Although differing in structure from typical nicotinic agonists, based on crystallographic data with the acetylcholine binding protein, they appeared to engage the site shared by such typical orthosteric agonists. Using oocytes expressing human α7 receptors, we found that the DPPs were efficacious activators of the receptor, with currents showing rapid desensitization characteristic of α7 receptors. However, we note that the rate of recovery from this desensitization depends strongly on structural features within the DPP family. Although the activation of receptors by DPP was blocked by the competitive antagonist methyllycaconitine (MLA), MLA had no effect on the DPP-induced desensitization, suggesting multiple modes of DPP binding. As expected, the desensitized conformational states could be reactivated by PAMs. Mutants made insensitive to acetylcholine by the C190A mutation in the agonist binding site were weakly activated by DPPs. The observation that activation of C190A mutants by the DPP compounds was resistant to the allosteric antagonist (-)cis-trans-4-(2,3,5,6-tetramethylphenyl)-3a,4,5,9b-tetrahydro-3H-cyclopenta[c]quinoline-8-sulfonamide supports the hypothesis that the activity of these noncanonical agonists in the orthosteric binding sites was not entirely dependent on the classic epitopes controlling activation by typical agonists and that perhaps they may access alternative modes for promoting the conformational changes associated with activation and desensitization. SIGNIFICANCE STATEMENT: This study reports a family of nicotinic acetylcholine receptor agonists that break the rules about what the structure of a nicotinic acetylcholine receptor agonist should be. It shows that the activity of these noncanonical agonists in the orthosteric binding sites is not dependent on the classical epitopes controlling activation by typical agonists and that through different binding poses, they promote unique conformational changes associated with receptor activation and desensitization.
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Affiliation(s)
- Clare Stokes
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California-San Diego, La Jolla, California (G.A.C.-H., X.W., P.T.); Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida (C.S., R.L.P.); and Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts (G.A.T.)
| | - Gisela Andrea Camacho-Hernandez
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California-San Diego, La Jolla, California (G.A.C.-H., X.W., P.T.); Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida (C.S., R.L.P.); and Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts (G.A.T.)
| | - Ganesh A Thakur
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California-San Diego, La Jolla, California (G.A.C.-H., X.W., P.T.); Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida (C.S., R.L.P.); and Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts (G.A.T.)
| | - Xiaoxuan Wu
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California-San Diego, La Jolla, California (G.A.C.-H., X.W., P.T.); Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida (C.S., R.L.P.); and Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts (G.A.T.)
| | - Palmer Taylor
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California-San Diego, La Jolla, California (G.A.C.-H., X.W., P.T.); Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida (C.S., R.L.P.); and Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts (G.A.T.)
| | - Roger L Papke
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California-San Diego, La Jolla, California (G.A.C.-H., X.W., P.T.); Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida (C.S., R.L.P.); and Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts (G.A.T.)
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Costa M, Blaschke TF, Amara SG, Meyer UA, Insel PA. Introduction to the Theme "Old and New Toxicology: Interfaces with Pharmacology". Annu Rev Pharmacol Toxicol 2021; 61:1-7. [PMID: 33411582 DOI: 10.1146/annurev-pharmtox-092220-033032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The theme of Volume 61 is "Old and New Toxicology: Interfaces with Pharmacology." Old toxicology is exemplified by the authors of the autobiographical articles: B.M. Olivera's work on toxins and venoms from cone snails and P. Taylor's studies of acetylcholinesterase and the nicotinic cholinergic receptor, which serve as sites of action for numerous pesticides and venoms. Other articles in this volume focus on new understanding and new types of toxicology, including (a) arsenic toxicity, which is an ancient poison that, through evolution, has caused most multicellular organisms to express an active arsenic methyltransferase to methylate arsenite, which accelerates the excretion of arsenic from the body; (b) small molecules that react with lipid dicarbonyls, which are now considered the most toxic oxidative stress end products; (c) immune checkpoint inhibitors (ICIs), which have revolutionized cancer therapy but have numerous immune-related adverse events, including cardiovascular complications; (d) autoimmunity caused by the environment; (e) idiosyncratic drug-induced liver disease, which together with the toxicity of ICIs represents new toxicology interfacing with pharmacology; and (f) sex differences in the development of cardiovascular disease, with men more susceptible than women to vascular inflammation that initiates and perpetuates disease. These articles and others in Volume 61 reflect the interface and close integration of pharmacology and toxicology that began long ago but continues today.
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Affiliation(s)
- Max Costa
- Department of Environmental Medicine, NYU Grossman School of Medicine, New York, New York 10010, USA;
| | | | - Susan G Amara
- National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Urs A Meyer
- Biozentrum, University of Basel, CH-4056 Basel, Switzerland
| | - Paul A Insel
- Departments of Pharmacology and Medicine, University of California, San Diego, La Jolla, California 92093, USA
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Elephants in the Dark: Insights and Incongruities in Pentameric Ligand-gated Ion Channel Models. J Mol Biol 2021; 433:167128. [PMID: 34224751 DOI: 10.1016/j.jmb.2021.167128] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 06/25/2021] [Accepted: 06/25/2021] [Indexed: 02/06/2023]
Abstract
The superfamily of pentameric ligand-gated ion channels (pLGICs) comprises key players in electrochemical signal transduction across evolution, including historic model systems for receptor allostery and targets for drug development. Accordingly, structural studies of these channels have steadily increased, and now approach 250 depositions in the protein data bank. This review contextualizes currently available structures in the pLGIC family, focusing on morphology, ligand binding, and gating in three model subfamilies: the prokaryotic channel GLIC, the cation-selective nicotinic acetylcholine receptor, and the anion-selective glycine receptor. Common themes include the challenging process of capturing and annotating channels in distinct functional states; partially conserved gating mechanisms, including remodeling at the extracellular/transmembrane-domain interface; and diversity beyond the protein level, arising from posttranslational modifications, ligands, lipids, and signaling partners. Interpreting pLGIC structures can be compared to describing an elephant in the dark, relying on touch alone to comprehend the many parts of a monumental beast: each structure represents a snapshot in time under specific experimental conditions, which must be integrated with further structure, function, and simulations data to build a comprehensive model, and understand how one channel may fundamentally differ from another.
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8
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Abstract
The α7-type nicotinic acetylcholine receptor is one of the most unique and interesting of all the members of the cys-loop superfamily of ligand-gated ion channels. Since it was first identified initially as a binding site for α-bungarotoxin in mammalian brain and later as a functional homomeric receptor with relatively high calcium permeability, it has been pursued as a potential therapeutic target for numerous indications, from Alzheimer disease to asthma. In this review, we discuss the history and state of the art for targeting α7 receptors, beginning with subtype-selective agonists and the basic pharmacophore for the selective activation of α7 receptors. A key feature of α7 receptors is their rapid desensitization by standard "orthosteric" agonist, and we discuss insights into the conformational landscape of α7 receptors that has been gained by the development of ligands binding to allosteric sites. Some of these sites are targeted by positive allosteric modulators that have a wide range of effects on the activation profile of the receptors. Other sites are targeted by direct allosteric agonist or antagonists. We include a perspective on the potential importance of α7 receptors for metabotropic as well as ionotropic signaling. We outline the challenges that exist for future development of drugs to target this important receptor and approaches that may be considered to address those challenges. SIGNIFICANCE STATEMENT: The α7-type nicotinic acetylcholine receptor (nAChR) is acknowledged as a potentially important therapeutic target with functional properties associated with both ionotropic and metabotropic signaling. The functional properties of α7 nAChR can be regulated in diverse ways with the variety of orthosteric and allosteric ligands described in this review.
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Affiliation(s)
- Roger L Papke
- Departments of Pharmacology and Therapeutics (R.L.P) and Chemistry (N.A.H.), University of Florida, Gainesville, FL
| | - Nicole A Horenstein
- Departments of Pharmacology and Therapeutics (R.L.P) and Chemistry (N.A.H.), University of Florida, Gainesville, FL
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9
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Taylor P, Shyong YJ, Samskey N, Ho KY, Radic' Z, Fenical W, Sharpless KB, Kovarik Z, Camacho-Hernandez GA. Ligand design for human acetylcholinesterase and nicotinic acetylcholine receptors, extending beyond the conventional and canonical. J Neurochem 2021; 158:1217-1222. [PMID: 33638151 DOI: 10.1111/jnc.15335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 01/22/2021] [Accepted: 02/21/2021] [Indexed: 12/31/2022]
Abstract
We detail here distinctive departures from lead classical cholinesterase re-activators, the pyridinium aldoximes, to achieve rapid CNS penetration and reactivation of AChE in the CNS (brain and spinal cord). Such reactivation is consistent with these non-canonical re-activators enhancing survival parameters in both mice and macaques following exposure to organophosphates. Thus, the ideal cholinesterase re-activator should show minimal toxicity, limited inhibitory activity in the absence of an organophosphate, and rapid CNS penetration, in addition to its nucleophilic potential at the target, the conjugated AChE active center. These are structural properties directed to reactivity profiles at the conjugated AChE active center, reinforced by the pharmacokinetic and tissue disposition properties of the re-activator leads. In the case of nicotinic acetylcholine receptor (nAChR) agonists and antagonists, with the many existing receptor subtypes in mammals, we prioritize subtype selectivity in their design. In contrast to nicotine and its analogues that react with panoply of AChR subtypes, the substituted di-2-picolyl amine pyrimidines possess distinctive ionization characteristics reflecting in selectivity for the orthosteric site at the α7 subtypes of receptor. Here, entry to the CNS should be prioritized for the therapeutic objectives of the nicotinic agent influencing aberrant CNS activity in development or in the sequence of CNS ageing (longevity) in mammals, along with general peripheral activities controlling inflammation.
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Affiliation(s)
- Palmer Taylor
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, CA, USA
| | - Yan-Jye Shyong
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, CA, USA
| | - Nathan Samskey
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, CA, USA
| | - Kwok-Yiu Ho
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, CA, USA
| | - Zoran Radic'
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, CA, USA
| | - William Fenical
- Scripps Institution of Oceanography, University of California, CA, USA
| | - K Barry Sharpless
- Skaggs Institute for Chemical Biology, The Scripps Research Institute, San Diego, CA, USA
| | - Zrinka Kovarik
- Institute for Medical Research and Occupational Health, Zagreb, Croatia
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10
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Son L, Kryukova E, Ziganshin R, Andreeva T, Kudryavtsev D, Kasheverov I, Tsetlin V, Utkin Y. Novel Three-Finger Neurotoxins from Naja melanoleuca Cobra Venom Interact with GABA A and Nicotinic Acetylcholine Receptors. Toxins (Basel) 2021; 13:toxins13020164. [PMID: 33672715 PMCID: PMC7924340 DOI: 10.3390/toxins13020164] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 02/08/2023] Open
Abstract
Cobra venoms contain three-finger toxins (TFT) including α-neurotoxins efficiently binding nicotinic acetylcholine receptors (nAChRs). As shown recently, several TFTs block GABAA receptors (GABAARs) with different efficacy, an important role of the TFTs central loop in binding to these receptors being demonstrated. We supposed that the positive charge (Arg36) in this loop of α-cobratoxin may explain its high affinity to GABAAR and here studied α-neurotoxins from African cobra N. melanoleuca venom for their ability to interact with GABAARs and nAChRs. Three α-neurotoxins, close homologues of the known N. melanoleuca long neurotoxins 1 and 2, were isolated and sequenced. Their analysis on Torpedocalifornica and α7 nAChRs, as well as on acetylcholine binding proteins and on several subtypes of GABAARs, showed that all toxins interacted with the GABAAR much weaker than with the nAChR: one neurotoxin was almost as active as α-cobratoxin, while others manifested lower activity. The earlier hypothesis about the essential role of Arg36 as the determinant of high affinity to GABAAR was not confirmed, but the results obtained suggest that the toxin loop III may contribute to the efficient interaction of some long-chain neurotoxins with GABAAR. One of isolated toxins manifested different affinity to two binding sites on Torpedo nAChR.
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Affiliation(s)
- Lina Son
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (L.S.); (E.K.); (R.Z.); (T.A.); (D.K.); (I.K.); (V.T.)
- Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
| | - Elena Kryukova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (L.S.); (E.K.); (R.Z.); (T.A.); (D.K.); (I.K.); (V.T.)
| | - Rustam Ziganshin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (L.S.); (E.K.); (R.Z.); (T.A.); (D.K.); (I.K.); (V.T.)
| | - Tatyana Andreeva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (L.S.); (E.K.); (R.Z.); (T.A.); (D.K.); (I.K.); (V.T.)
| | - Denis Kudryavtsev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (L.S.); (E.K.); (R.Z.); (T.A.); (D.K.); (I.K.); (V.T.)
| | - Igor Kasheverov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (L.S.); (E.K.); (R.Z.); (T.A.); (D.K.); (I.K.); (V.T.)
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, ul. Trubetskaya 8, bld. 2, 119991 Moscow, Russia
| | - Victor Tsetlin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (L.S.); (E.K.); (R.Z.); (T.A.); (D.K.); (I.K.); (V.T.)
| | - Yuri Utkin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (L.S.); (E.K.); (R.Z.); (T.A.); (D.K.); (I.K.); (V.T.)
- Correspondence: ; Tel.: +7-495-3366522
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Abstract
Herein, I intend to capture highlights shared with my academic and research colleagues over the 60 years I devoted initially to my graduate and postdoctoral training and then to academic endeavors starting as an assistant professor in a new medical school at the University of California, San Diego (UCSD). During this period, the Department of Pharmacology emerged from a division within the Department of Medicine to become the first basic science department, solely within the School of Medicine at UCSD in 1979. As part of the school's plans to reorganize and to retain me at UCSD, I was appointed as founding chair. Some years later in 2002, faculty, led largely within the Department of Pharmacology and by practicing pharmacists within UCSD Healthcare, started the independent Skaggs School of Pharmacy and Pharmaceutical Sciences with a doctor of pharmacy (PharmD) program, where I served as the founding dean. My career pathway, from working at my family-owned pharmacy to chairing a department in a school of medicine and then becoming the dean of a school of pharmacy at a research-intensive, student-centered institution, involved some risky decisions. But the academic, curricular, and accreditation challenges posed were met by a cadre of creative faculty colleagues. I offer my experiences to individuals confronted with a multiplicity of real or imagined opportunities in academic health sciences, the related pharmaceutical industry, and government oversight agencies.
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Affiliation(s)
- Palmer Taylor
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, and School of Medicine, University of California, San Diego, La Jolla, California 92093, USA
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