1
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Heinz CS, Bermudez M, Jaiswal N, Große C, Kauk M, Hoffmann C, Holzgrabe U. Hybridization into a Bitopic Ligand Increased Muscarinic Receptor Activation for Isopilocarpine but Not for Pilocarpine Derivatives. JOURNAL OF NATURAL PRODUCTS 2023; 86:869-881. [PMID: 37042802 DOI: 10.1021/acs.jnatprod.2c01079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Pilocarpine (1), a secondary metabolite of several Pilocarpus species, is a therapeutically used partial agonist of muscarinic acetylcholine receptors (mAChRs). The available pharmacological data and structure-activity relationships do not provide comparable data for all five receptor subtypes. In this study, pilocarpine (1), its epimer isopilocarpine (2), racemic analogues pilosinine (3) and desmethyl pilosinine (4), and the respective hybrid ligands with a naphmethonium fragment (5-C6 to 8-C6) were synthesized and analyzed in mini-G nano-BRET assays at the five mAChRs. In line with earlier studies, pilocarpine was the most active compound among the orthosteric ligands 1-4. Computational docking of pilocarpine and isopilocarpine to the active M2 receptor suggests that the trans-configuration of isopilocarpine leads to a loss of the hydrogen bond from the lactone carbonyl to N6.52, explaining the lower activity of isopilocarpine. Hybrid formation of pilocarpine (1) and isopilocarpine (2) led to an inverted activity rank, with the trans-configured isopilocarpine hybrid (6-C6) being more active. The hydrogen bond of interest is formed by the isopilocarpine hybrid (6-C6) but not by the pilocarpine hybrid (5-C6). Hybridization thus leads to a modified binding mode of the orthosteric moiety, as the binding mode of the hybrid is dominated by the high-affinity allosteric moiety.
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Affiliation(s)
- Christine S Heinz
- Department of Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Marcel Bermudez
- Institute of Pharmaceutical and Medicinal Chemistry, Westfälische Wilhelms-Universität, Corrensstraße 48, 48149 Muenster, Germany
| | - Natasha Jaiswal
- Institute for Molecular Cell Biology, CMB-Center for Molecular Biomedicine, University Hospital Jena, Friedrich-Schiller University Jena, Hans-Knöll-Straße 2, 07745 Jena, Germany
| | - Carolin Große
- Institute for Molecular Cell Biology, CMB-Center for Molecular Biomedicine, University Hospital Jena, Friedrich-Schiller University Jena, Hans-Knöll-Straße 2, 07745 Jena, Germany
| | - Michael Kauk
- Institute for Molecular Cell Biology, CMB-Center for Molecular Biomedicine, University Hospital Jena, Friedrich-Schiller University Jena, Hans-Knöll-Straße 2, 07745 Jena, Germany
| | - Carsten Hoffmann
- Institute for Molecular Cell Biology, CMB-Center for Molecular Biomedicine, University Hospital Jena, Friedrich-Schiller University Jena, Hans-Knöll-Straße 2, 07745 Jena, Germany
| | - Ulrike Holzgrabe
- Department of Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
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2
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Matera C, Kauk M, Cirillo D, Maspero M, Papotto C, Volpato D, Holzgrabe U, De Amici M, Hoffmann C, Dallanoce C. Novel Xanomeline-Containing Bitopic Ligands of Muscarinic Acetylcholine Receptors: Design, Synthesis and FRET Investigation. Molecules 2023; 28:molecules28052407. [PMID: 36903650 PMCID: PMC10005175 DOI: 10.3390/molecules28052407] [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: 01/30/2023] [Revised: 03/01/2023] [Accepted: 03/03/2023] [Indexed: 03/08/2023] Open
Abstract
In the last few years, fluorescence resonance energy transfer (FRET) receptor sensors have contributed to the understanding of GPCR ligand binding and functional activation. FRET sensors based on muscarinic acetylcholine receptors (mAChRs) have been employed to study dual-steric ligands, allowing for the detection of different kinetics and distinguishing between partial, full, and super agonism. Herein, we report the synthesis of the two series of bitopic ligands, 12-Cn and 13-Cn, and their pharmacological investigation at the M1, M2, M4, and M5 FRET-based receptor sensors. The hybrids were prepared by merging the pharmacophoric moieties of the M1/M4-preferring orthosteric agonist Xanomeline 10 and the M1-selective positive allosteric modulator 77-LH-28-1 (1-[3-(4-butyl-1-piperidinyl)propyl]-3,4-dihydro-2(1H)-quinolinone) 11. The two pharmacophores were connected through alkylene chains of different lengths (C3, C5, C7, and C9). Analyzing the FRET responses, the tertiary amine compounds 12-C5, 12-C7, and 12-C9 evidenced a selective activation of M1 mAChRs, while the methyl tetrahydropyridinium salts 13-C5, 13-C7, and 13-C9 showed a degree of selectivity for M1 and M4 mAChRs. Moreover, whereas hybrids 12-Cn showed an almost linear response at the M1 subtype, hybrids 13-Cn evidenced a bell-shaped activation response. This different activation pattern suggests that the positive charge anchoring the compound 13-Cn to the orthosteric site ensues a degree of receptor activation depending on the linker length, which induces a graded conformational interference with the binding pocket closure. These bitopic derivatives represent novel pharmacological tools for a better understanding of ligand-receptor interactions at a molecular level.
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Affiliation(s)
- Carlo Matera
- Department of Pharmaceutical Sciences, Medicinal Chemistry Section “Pietro Pratesi”, University of Milan, Via L. Mangiagalli 25, 20133 Milan, Italy
| | - Michael Kauk
- Institute for Molecular Cell Biology, Center for Molecular Biomedicine, University Hospital Jena, Friedrich Schiller University Jena, Hans Knoell Str. 2, 07745 Jena, Germany
| | - Davide Cirillo
- Department of Pharmaceutical Sciences, Medicinal Chemistry Section “Pietro Pratesi”, University of Milan, Via L. Mangiagalli 25, 20133 Milan, Italy
| | - Marco Maspero
- Department of Pharmaceutical Sciences, Medicinal Chemistry Section “Pietro Pratesi”, University of Milan, Via L. Mangiagalli 25, 20133 Milan, Italy
| | - Claudio Papotto
- Department of Pharmaceutical Sciences, Medicinal Chemistry Section “Pietro Pratesi”, University of Milan, Via L. Mangiagalli 25, 20133 Milan, Italy
| | - Daniela Volpato
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ulrike Holzgrabe
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Marco De Amici
- Department of Pharmaceutical Sciences, Medicinal Chemistry Section “Pietro Pratesi”, University of Milan, Via L. Mangiagalli 25, 20133 Milan, Italy
| | - Carsten Hoffmann
- Institute for Molecular Cell Biology, Center for Molecular Biomedicine, University Hospital Jena, Friedrich Schiller University Jena, Hans Knoell Str. 2, 07745 Jena, Germany
| | - Clelia Dallanoce
- Department of Pharmaceutical Sciences, Medicinal Chemistry Section “Pietro Pratesi”, University of Milan, Via L. Mangiagalli 25, 20133 Milan, Italy
- Correspondence: ; Tel.: +39-02-503-19327
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3
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Schmitz J, van der Mey D, Bermudez M, Klöckner J, Schrage R, Kostenis E, Tränkle C, Wolber G, Mohr K, Holzgrabe U. Dualsteric Muscarinic Antagonists–Orthosteric Binding Pose Controls Allosteric Subtype Selectivity. J Med Chem 2014; 57:6739-50. [DOI: 10.1021/jm500790x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Jens Schmitz
- Institute
of Pharmacy and Food Chemistry, University of Würzburg, Am
Hubland, D-97074 Würzburg, Germany
| | - Dorina van der Mey
- Pharmacology
and Toxicology, Institute of Pharmacy, Gerhard-Domagk-Straße 3,D-53121 Bonn, Germany
| | - Marcel Bermudez
- Institute
for Pharmacy, Free University Berlin, Königin-Luise-Straße
2 und 4, D-14195 Berlin, Germany
| | - Jessica Klöckner
- Institute
of Pharmacy and Food Chemistry, University of Würzburg, Am
Hubland, D-97074 Würzburg, Germany
| | - Ramona Schrage
- Pharmacology
and Toxicology, Institute of Pharmacy, Gerhard-Domagk-Straße 3,D-53121 Bonn, Germany
| | - Evi Kostenis
- Institute
of Pharmaceutical Biology, Molecular-, Cellular-, and Pharmacobiology
Section, University of Bonn, Nussallee 6, D-53115 Bonn, Germany
| | - Christian Tränkle
- Pharmacology
and Toxicology, Institute of Pharmacy, Gerhard-Domagk-Straße 3,D-53121 Bonn, Germany
| | - Gerhard Wolber
- Institute
for Pharmacy, Free University Berlin, Königin-Luise-Straße
2 und 4, D-14195 Berlin, Germany
| | - Klaus Mohr
- Pharmacology
and Toxicology, Institute of Pharmacy, Gerhard-Domagk-Straße 3,D-53121 Bonn, Germany
| | - Ulrike Holzgrabe
- Institute
of Pharmacy and Food Chemistry, University of Würzburg, Am
Hubland, D-97074 Würzburg, Germany
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4
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Matera C, Flammini L, Quadri M, Vivo V, Ballabeni V, Holzgrabe U, Mohr K, De Amici M, Barocelli E, Bertoni S, Dallanoce C. Bis(ammonio)alkane-type agonists of muscarinic acetylcholine receptors: Synthesis, in vitro functional characterization, and in vivo evaluation of their analgesic activity. Eur J Med Chem 2014; 75:222-32. [DOI: 10.1016/j.ejmech.2014.01.032] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 01/15/2014] [Accepted: 01/20/2014] [Indexed: 10/25/2022]
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5
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Mohr K, Schmitz J, Schrage R, Tränkle C, Holzgrabe U. Molecular Alliance-From Orthosteric and Allosteric Ligands to Dualsteric/Bitopic Agonists at G Protein Coupled Receptors. Angew Chem Int Ed Engl 2012; 52:508-16. [DOI: 10.1002/anie.201205315] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Indexed: 11/09/2022]
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6
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Mohr K, Schmitz J, Schrage R, Tränkle C, Holzgrabe U. Molekulare Allianz - von orthosterischen und allosterischen Liganden zu dualsterischen/bitopischen Agonisten G-Protein-gekoppelter Rezeptoren. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201205315] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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7
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Kuran B, Krawiecka M, Kossakowski J, Szymanek K, Kierzkowska M, Młynarczyk G. Synthesis and antimicrobial activity of derivatives of 1H-benzo[de]isoquinoline-1,3(2H)-dione. HETEROCYCL COMMUN 2012. [DOI: 10.1515/hc-2012-0115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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8
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Baathulaa K, Xu Y, Qian X. Short and scalable synthesis of an anhydride precursor of the environment-sensitive fluorophore 6-dimethylaminonaphthalimide. Nat Protoc 2011; 6:1990-7. [DOI: 10.1038/nprot.2011.415] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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9
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Mode-of-action studies of the novel bisquaternary bisnaphthalimide MT02 against Staphylococcus aureus. Antimicrob Agents Chemother 2010; 55:311-20. [PMID: 20937782 DOI: 10.1128/aac.00586-10] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Screening of various bisquaternary bisnaphthalimides against a variety of human pathogens revealed one compound, designated MT02, with strong inhibitory effects against Gram-positive bacteria. The MICs ranged from 0.31 μg/ml against community-acquired methicillin-resistant Staphylococcus aureus (MRSA) lineage USA300 to 20 μg/ml against Streptococcus pneumoniae. Radioactive whole-cell labeling experiments indicated a strong impact of MT02 on bacterial DNA replication. DNA microarray studies generated a transcriptional signature characterized by stronger expression of genes involved in DNA metabolism, DNA replication, SOS response, and transport of positively charged compounds. Furthermore, surface plasmon resonance and gel retardation experiments demonstrated direct binding of MT02 to DNA in a concentration-dependent, reversible, and non-sequence-specific manner. The data presented suggest that the bisquaternary bisnaphthalimide MT02 exerts anti-Gram-positive activity by binding to DNA and thereby preventing appropriate DNA replication.
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10
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New efficient access to fused (Het)Aryltetrahydroindolizinones via N-acyl iminium intermediates. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.03.100] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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11
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Tischer M, Sologub L, Pradel G, Holzgrabe U. The bisnaphthalimides as new active lead compounds against Plasmodium falciparum. Bioorg Med Chem 2010; 18:2998-3003. [PMID: 20382538 DOI: 10.1016/j.bmc.2010.03.067] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Revised: 03/22/2010] [Accepted: 03/25/2010] [Indexed: 11/18/2022]
Abstract
The bisquaternary bisnaphthalimides are a versatile class of compounds being active against the malaria parasite Plasmodium falciparum in the lower nanomolar range of concentration combined with no cytotoxicity. The series of compounds is designed as choline analogues and interfering agents of the phosphatidylcholine biosynthesis. The qualitative analysis of the structure-activity relationships (SAR) revealed the importance of a long methylene middle chain of at least 8 methylene groups between the two bisquaternary naphthalimides or a monoquaternary naphthalimide consisting of a long alkyl chain attached to the positively charged nitrogen atom. Since the SARs are different from reported biscationic antimalarial drugs the mode of action remains to be elucidated.
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Affiliation(s)
- Maximilian Tischer
- Institute of Pharmacy and Food Chemistry, University of Wuerzburg, Am Hubland, 97074 Wuerzburg, Germany
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12
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Jäger D, Schmalenbach C, Prilla S, Schrobang J, Kebig A, Sennwitz M, Heller E, Tränkle C, Holzgrabe U, Höltje HD, Mohr K. Allosteric small molecules unveil a role of an extracellular E2/transmembrane helix 7 junction for G protein-coupled receptor activation. J Biol Chem 2007; 282:34968-76. [PMID: 17890226 DOI: 10.1074/jbc.m705563200] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
G protein-coupled receptors represent the largest superfamily of cell membrane-spanning receptors. We used allosteric small molecules as a novel approach to better understand conformational changes underlying the inactive-to-active switch in native receptors. Allosteric molecules bind outside the orthosteric area for the endogenous receptor activator. The human muscarinic M(2) acetylcholine receptor is prototypal for the study of allosteric interactions. We measured receptor-mediated G protein activation, applied a series of structurally diverse muscarinic allosteric agents, and analyzed their cooperative effects with orthosteric receptor agonists. A strong negative cooperativity of receptor binding was observed with acetylcholine and other full agonists, whereas a pronounced negative cooperativity of receptor activation was observed with the partial agonist pilocarpine. Applying a newly synthesized allosteric tool, point mutated receptors, radioligand binding, and a three-dimensional receptor model, we found that the deviating allosteric/orthosteric interactions are mediated through the core region of the allosteric site. A key epitope is M(2)Trp(422) in position 7.35 that is located at the extracellular top of transmembrane helix 7 and that contacts, in the inactive receptor, the extracellular loop E2. Trp 7.35 is critically involved in the divergent allosteric/orthosteric cooperativities with acetylcholine and pilocarpine, respectively. In the absence of allosteric agents, Trp 7.35 is essential for receptor binding of the full agonist and for receptor activation by the partial agonist. This study provides first evidence for a role of an allosteric E2/transmembrane helix 7 contact region for muscarinic receptor activation by orthosteric agonists.
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Affiliation(s)
- Dorothea Jäger
- Pharmacology and Toxicology Section, Institute of Pharmacy, Rheinische Friedrich-Wilhelms-University, D-53121 Bonn, Germany
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13
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Muth M, Hoerr V, Glaser M, Ponte-Sucre A, Moll H, Stich A, Holzgrabe U. Antitrypanosomal activity of quaternary naphthalimide derivatives. Bioorg Med Chem Lett 2007; 17:1590-3. [PMID: 17239596 DOI: 10.1016/j.bmcl.2006.12.088] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2006] [Revised: 12/21/2006] [Accepted: 12/26/2006] [Indexed: 10/23/2022]
Abstract
Sleeping sickness caused by Trypanosoma brucei gambiense and rhodesiense is fatal if left untreated. Due to the toxicity of drugs currently used and the emerging resistance against these drugs new lead compounds are urgently needed. Within the frame of a broad screening program for drugs with antitrypanosomal activity, some highly potent tertiary and quaternary mono- and bisnaphthalimides being active in the lower micromolar and nanomolar range of concentration have been identified. These compounds are easily available via a two- or three-step microwave-driven synthesis with high yield.
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Affiliation(s)
- Mathias Muth
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Wuerzburg, Germany
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14
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Schmitz J, Heller E, Holzgrabe U. A Fast and Efficient Track to Allosteric Modulators of Muscarinic Receptors: Microwave-Assisted Syntheses. MONATSHEFTE FUR CHEMIE 2007. [DOI: 10.1007/s00706-006-0575-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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15
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Sürig U, Gaal K, Kostenis E, Tränkle C, Mohr K, Holzgrabe U. Muscarinic allosteric modulators: atypical structure-activity-relationships in bispyridinium-type compounds. Arch Pharm (Weinheim) 2006; 339:207-12. [PMID: 16572483 DOI: 10.1002/ardp.200600005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Allosteric modulators of receptor binding are known for a variety of membrane receptors. In case of muscarinic receptors, a considerable number of structurally divergent modulators have been described. For the M2 receptor subtype which has a high sensitivity to allosteric modulation most of the allosteric agents bind to the common allosteric binding site of the receptor protein. In this study, a series of DUO compounds characterized by a bispyridinium middle chain and lateral benzyloximeether moieties of a systematically varied substitution pattern has been evaluated with regard to their allosteric potency to affect M2 receptors, whose orthosteric site was blocked by [3H]N-methylscopolamine. The variations in potency were found to be surprisingly small and the structure-activity relationships of the DUO compounds diverged from those of correspondingly substituted hexamethonio-type allosteric modulators. One has to conclude that DUO compounds bind in an "atypical" manner which is in agreement with recently reported side-directed mutagenesis and molecular modeling studies.
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Affiliation(s)
- Ulf Sürig
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Würzburg, Germany
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16
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Prilla S, Schrobang J, Ellis J, Höltje HD, Mohr K. Allosteric Interactions with Muscarinic Acetylcholine Receptors: Complex Role of the Conserved Tryptophan M2422Trp in a Critical Cluster of Amino Acids for Baseline Affinity, Subtype Selectivity, and Cooperativity. Mol Pharmacol 2006; 70:181-93. [PMID: 16641315 DOI: 10.1124/mol.106.023481] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In general, the M2 subtype of muscarinic acetylcholine receptors has the highest sensitivity for allosteric modulators and the M5 subtype the lowest. The M2/M5 selectivity of some structurally diverse allosteric agents is known to be completely explained by M2 177Tyr and M2 423Thr in receptors whose orthosteric site is occupied by the conventional ligand N-methylscopolamine (NMS). This study explored the role of the conserved M2 422Trp and the adjacent M2 423Thr in the binding of alkane-bisammonio type modulators, gallamine, and diallylcaracurine V. Experiments were performed with human M2 or M5 receptors or mutants thereof. It was found that M2 422Trp and M2 423Thr independently influenced allosteric agent binding. The presence of M2 423Thr may enhance the affinity of binding, depending on the allosteric agent, either directly or indirectly (by avoiding sterical hindrance through its M5 counterpart 478His). Replacement of M2 422Trp and of the corresponding M5 477Trp by alanine revealed a pronounced contribution of these epitopes to subtype independent baseline affinity in NMS-bound and NMS-free receptors for all agents except diallylcaracurine V. In a few instances, this tryptophan also influenced cooperativity and subtype selectivity. Docking simulations using a three-dimensional M2 receptor model revealed that the aromatic rings of M2 177Tyr and M2 422Trp, in a concerted action, might fix one of the aromatic moieties of alkane-bisammonio compounds between them. Thus, M2 422Trp and the spatially adjacent M2 177Tyr, as well as M2 423Thr, form a cluster of amino acids within the allosteric binding cleft that is pivotal for both M2/M5 subtype selectivity and baseline affinity of allosteric agents.
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Affiliation(s)
- Stefanie Prilla
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Bonn, 53121 Bonn (Germany)
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17
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Disingrini T, Muth M, Dallanoce C, Barocelli E, Bertoni S, Kellershohn K, Mohr K, De Amici M, Holzgrabe U. Design, synthesis, and action of oxotremorine-related hybrid-type allosteric modulators of muscarinic acetylcholine receptors. J Med Chem 2006; 49:366-72. [PMID: 16392821 DOI: 10.1021/jm050769s] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel series of muscarinic receptor ligands of the hexamethonio-type was prepared which contained, on one side, the phthalimidopropane or 1,8-naphthalimido-2,2-dimethylpropane moiety typical for subtype selective allosteric antagonists and, on the other, the acetylenic fragment typical for the nonselective orthosteric muscarinic agonists oxotremorine, oxotremorine-M, and related muscarinic agonists. Binding experiments in M(2) receptors using [(3)H]N-methylscopolamine as an orthosteric probe proved an allosteric action of both groups of hybrids, 7a-10a and 8b-10b. The difference in activity between a-group and b-group hybrids corresponded with the activity difference between the allosteric parent compounds. In M(1)-M(3) muscarinic isolated organ preparations, most of the hybrids behaved as subtype selective antagonists. [(35)S]GTPgammaS binding assays using human M(2) receptors overexpressed in CHO cells revealed that a weak intrinsic efficacy was preserved in 8b-10b. Thus, attaching muscarinic allosteric antagonist moieties to orthosteric muscarinic agonists may lead to hybrid compounds in which functions of both components are mixed.
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Affiliation(s)
- Teresa Disingrini
- Istituto di Chimica Farmaceutica e Tossicologica, Università degli Studi di Milano, Viale Abruzzi 42, 20131 Milano, Italy
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18
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Grossmüller M, Antony J, Tränkle C, Holzgrabe U, Mohr K. Allosteric site in M2 acetylcholine receptors: evidence for a major conformational change upon binding of an orthosteric agonist instead of an antagonist. Naunyn Schmiedebergs Arch Pharmacol 2005; 372:267-76. [PMID: 16362429 DOI: 10.1007/s00210-005-0023-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2005] [Accepted: 11/21/2005] [Indexed: 10/25/2022]
Abstract
Muscarinic acetylcholine receptors contain two distinct ligand binding sites, i.e. the orthosteric site for acetylcholine and other conventional ligands, and an allosteric site located at the entrance of the ligand binding pocket. We used a set of allosteric agents to probe whether muscarinic M2 receptors whose orthosteric site is occupied by an agonist still reveal the common allosteric site that has been identified in M2 receptors being occupied by an orthosteric antagonist (N-methylscopolamine, NMS). Equilibrium and dissociation binding experiments were carried out in porcine heart homogenates using either the agonist [3H]oxotremorine M ([3H]OxoM) or the antagonist [3H]NMS. The affinities of the allosteric agents were determined for the radioligand-occupied receptor states and, additionally, for the radioligand-free (ground state) M2 receptor. The archetypal agent W84 (hexane-1,6-bis[dimethyl-3'-phthalimidopropyl-ammonium bromide] and its bispyridinio middle chain analogue WDuo3 (1,3-bis[4-(phthalimidomethoxyimino-methyl)-pyridinium-1-yl]propane dibromide) had a clearly lower affinity for [3H]OxoM-liganded receptors compared with [3H]NMS-liganded and ground state receptors. In contrast, a derivative resembling only one half of W84 had equal affinities for both radioligand-occupied receptor states. Also, the agents gallamine and obidoxime did not discriminate between [3H]OxoM- and [3H]NMS-occupied receptors. The allosteric antagonistic tool obidoxime inhibited WDuo3 action in [3H]OxoM-liganded receptors with the same potency as in [3H]NMS-liganded receptors. We conclude that the common allosteric site is still present in OxoM-liganded M2 receptors, but its spatial conformation is considerably altered compared with NMS-liganded receptors.
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Affiliation(s)
- Maren Grossmüller
- Pharmacology and Toxicology, Institute of Pharmacy, University of Bonn, Gerhard-Domagk-Str. 3, 53121, Bonn, Germany
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19
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Mathiesen JM, Ulven T, Martini L, Gerlach LO, Heinemann A, Kostenis E. Identification of indole derivatives exclusively interfering with a G protein-independent signaling pathway of the prostaglandin D2 receptor CRTH2. Mol Pharmacol 2005; 68:393-402. [PMID: 15870392 DOI: 10.1124/mol.104.010520] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The anti-inflammatory drugs indomethacin and ramatroban, the latter showing clinical efficacy in treating allergic asthma, have been shown to act as a classic agonist and antagonist, respectively, of the G protein-coupled chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2 receptor). Here, we report the identification of two indole derivatives 1-(4-ethoxyphenyl)-5-methoxy-2-methylindole-3-carboxylic acid and N(alpha)-tosyltryptophan (hereafter referred to as 1 and 2, respectively), which are structurally related to indomethacin and ramatroban but which selectively interfere with a specific G protein-independent signaling pathway of CRTH2. In whole-cell saturation-binding assays, 1 and 2 both increase the number of [(3)H]prostaglandin D2 (PGD2)-recognizing CRTH2 sites and the affinity of PGD2 for CRTH2. Enzyme-linked immunosorbent assays show that they do not alter the total number of CRTH2 receptors on the cell surface. Analysis of their binding mode indicates that unlike indomethacin or ramatroban, 1 and 2 can occupy CRTH2 simultaneously with PGD2. On a functional level, however, 1 and 2 do not interfere with PGD2-mediated activation of heterotrimeric G proteins by CRTH2. In contrast, both compounds inhibit PGD2-mediated arrestin translocation via a G protein-independent mechanism. In human eosinophils endogenously expressing CRTH2, 1 selectively decreases the efficacy but not the potency of PGD2-induced shape change, unlike ramatroban, which displays competitive antagonistic behavior. These data show for the first time that "antagonists" can cause markedly dissimilar degrees of inhibition for different effector pathways and suggest that it may be possible to develop novel classes of specific signal-inhibiting drugs distinct from conventional antagonists.
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Muth M, Sennwitz M, Mohr K, Holzgrabe U. Muscarinic Allosteric Enhancers of Ligand Binding: Pivotal Pharmacophoric Elements in Hexamethonio-Type Agents. J Med Chem 2005; 48:2212-7. [PMID: 15771463 DOI: 10.1021/jm049616f] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bisphthalimidopropyl-substituted hexamethonio compounds have been established as allosteric modulators of ligand binding to muscarinic acetylcholine receptors. Enhancers of ligand binding are of special interest. This study aimed to unravel the structural elements inducing positive cooperativity with the binding of an antagonist. [(3)H]-N-methylscopolamine binding to muscarinic M(2) receptors was measured in porcine heart homogenates. Dimethylation, but not monomethylation, of the lateral propyl chain in combination with an affinity increasing aromatic imide moiety, such as a 5-methylphthalimide and naphthalimide, on the same side of the molecule shifts the cooperativity toward positive values, resulting in enhancers of antagonist binding. Thus, lateral side chain dimethylation is a pivotal pharmacophoric element for positive cooperativity in hexamethonio-type muscarinic allosteric agents.
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Affiliation(s)
- Mathias Muth
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
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21
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Soudijn W, Van Wijngaarden I, IJzerman AP. Allosteric modulation of G protein-coupled receptors: perspectives and recent developments. Drug Discov Today 2004; 9:752-8. [PMID: 15450241 DOI: 10.1016/s1359-6446(04)03220-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Allosteric modulation of G protein-coupled receptors has recently been recognized as an alternative approach to gain selectivity in drug action. In this overview, allosteric modulators that enhance or diminish the effects of (endogenous) agonists or antagonists on a variety of G protein-coupled receptors are described. Emphasis is placed on the latest developments in this research area, including data on the first clinical studies. It appears that all three major classes of G protein-coupled receptors (A, B and C) are amenable to allosteric modulation by small molecules. This constitutes an attractive and novel means to identify new leads in the drug discovery process. However, it requires a re-engineering of the majority of current assays. Finally, it is suggested to introduce the term 'non-competitive agonism' or 'allosteric agonism' next to allosteric modulation.
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Affiliation(s)
- Willem Soudijn
- Division of Medicinal Chemistry Leiden/Amsterdam Center for Drug Research Leiden University PO Box 9502, 2300RA Leiden, The Netherlands
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Mohr M, Heller E, Ataie A, Mohr K, Holzgrabe U. Development of a new type of allosteric modulator of muscarinic receptors: hybrids of the antagonist AF-DX 384 and the hexamethonio derivative W84. J Med Chem 2004; 47:3324-7. [PMID: 15163212 DOI: 10.1021/jm031095t] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Various fragments of the hexamethonio-type allosteric agent W84 were linked to the secondary amino group of the muscarinic M(2) acetylcholine receptor-preferring antagonist AF-DX 384 to increase the area of attachment with the allosteric site. Addition of only the phthalimido moiety of W84 gave an allosteric enhancer of NMS binding. Thus, a new lead structure for the development of allosteric enhancers of NMS binding has been discovered.
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Affiliation(s)
- Marion Mohr
- Institute of Pharmacy and Food Chemistry, Pharmaceutical Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
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Zlotos DP, Buller S, Stiefl N, Baumann K, Mohr K. Probing the Pharmacophore for Allosteric Ligands of Muscarinic M2 Receptors: SAR and QSAR Studies in a Series of Bisquaternary Salts of Caracurine V and Related Ring Systems. J Med Chem 2004; 47:3561-71. [PMID: 15214783 DOI: 10.1021/jm0311341] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Allosteric effects on muscarinic acetylcholine M(2) receptors were examined in a series of bisquaternary salts of the Strychnos alkaloid caracurine V (6) and related iso-caracurine V, tetrahydrocaracurine V, and bisnortoxiferine ring systems. The compounds inhibited dissociation of the orthosteric antagonist [(3)H]N-methylscopolamine (NMS) from porcine cardiac M(2) receptors with EC(0.5,diss) values from 4 to 3270 nM. The majority of compounds hardly changed [(3)H]NMS equilibrium binding, indicating similar binding affinities in free and NMS-occupied M(2) receptors. The most potent agents were found in the caracurine V, iso-caracurine V, and tetrahydrocaracurine V series and carried nonpolar alkyl groups with a maximal chain length of three carbon atoms. 3D QSAR (CoMSIA) analysis explained the wide range of binding affinities by steric and electrostatic properties of the side chains. Furthermore, the findings suggest that the spatial orientation of the "caracurine" aromatic rings compared with the bisnortoxiferine ring skeleton is favorable to optimal allostere-receptor interactions.
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Affiliation(s)
- Darius P Zlotos
- Pharmaceutical Institute, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
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Zlotos DP, Buller S, Holzgrabe U, Mohr K. Bisquaternary dimers of strychnine and brucine. A new class of potent enhancers of antagonist binding to muscarinic M2 receptors. Bioorg Med Chem 2003; 11:2627-34. [PMID: 12757728 DOI: 10.1016/s0968-0896(03)00146-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bisquaternary dimers of strychnine and brucine were synthesized and their allosteric effect on muscarinic acetylcholine M(2) receptors was examined. The compounds retarded the dissociation of the antagonist [(3)H]N-methylscopolamine ([(3)H]NMS) from porcine cardiac cholinoceptors. This action indicated ternary complex formation. All compounds exhibited higher affinity to the allosteric site of [(3)H]NMS-occupied M(2) receptors than the monomeric strychnine and brucine, while the positive cooperativity with NMS was fully maintained. SAR studies revealed the unchanged strychnine ring as an important structural feature for high allosteric potency.
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Affiliation(s)
- D P Zlotos
- Pharmaceutical Institute, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
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