title: Carbachol dimers as homobivalent modulators of muscarinic receptors.
abstract: A series of homodimers of the well-known cholinergic agonist carbachol have been synthesized, showing the two agonist units symmetrically connected through a methylene chain of variable length. The new compounds have been tested on the five cloned muscarinic receptors (hM1-5) expressed in CHO cells by means of equilibrium binding studies, showing an increase in affinity by rising the number of methylene units up to 7 and 9. Functional experiments on guinea-pig ileum and assessment of ERK1/2 phosphorylation on hM1, hM2 and hM3 on CHO cells have shown that the new compounds are endowed with muscarinic antagonistic properties. Kinetic binding studies have revealed that some of the tested compounds are able to slow the rate of dissociation of NMS, suggesting a bitopic behavior. Docking simulations, performed on the hM1 and hM2 receptors, give a sound rationalization of the experimental data revealing how these compounds are able to interact with both orthosteric and allosteric binding sites depending on the length of their connecting chain.
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child's Health, Section of Pharmacology and Toxicology, University of Florence, Viale G. Pieraccini 6, 50139 Firenze, Italy. Electronic address: rosanna.matucci@unifi.it.
authors.forename: Rosanna
authors.initials: R
authors.lastname: Matucci
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child's Health, Section of Pharmacology and Toxicology, University of Florence, Viale G. Pieraccini 6, 50139 Firenze, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Nesi
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child's Health, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Via Ugo Schiff 6, 50019 Sesto Fiorentino, Italy.
authors.forename: Maria Vittoria
authors.initials: MV
authors.lastname: Martino
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child's Health, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Via Ugo Schiff 6, 50019 Sesto Fiorentino, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Bellucci
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child's Health, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Via Ugo Schiff 6, 50019 Sesto Fiorentino, Italy.
authors.forename: Dina
authors.initials: D
authors.lastname: Manetti
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child's Health, Section of Pharmacology and Toxicology, University of Florence, Viale G. Pieraccini 6, 50139 Firenze, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Ciuti
authors.affiliation: Department of Pharmaceutical Sciences, University of Milan, Via Mangiagalli 25, 20133 Milano, Italy.
authors.forename: Angelica
authors.initials: A
authors.lastname: Mazzolari
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child's Health, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Via Ugo Schiff 6, 50019 Sesto Fiorentino, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Dei
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child's Health, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Via Ugo Schiff 6, 50019 Sesto Fiorentino, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Guandalini
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child's Health, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Via Ugo Schiff 6, 50019 Sesto Fiorentino, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Teodori
authors.affiliation: Department of Pharmaceutical Sciences, University of Milan, Via Mangiagalli 25, 20133 Milano, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Vistoli
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child's Health, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Via Ugo Schiff 6, 50019 Sesto Fiorentino, Italy.
authors.forename: Maria Novella
authors.initials: MN
authors.lastname: Romanelli
mesh_terms: D000818:Animals; D001665:Binding Sites; D016466:CHO Cells; D002217:Carbachol / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*; D003412:Cricetulus; D019281:Dimerization; D006168:Guinea Pigs; D006801:Humans; D007082:Ileum / Q000187:drug effects / Q000502:physiology; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D062105:Molecular Docking Simulation; D018727:Muscarinic Antagonists / Q000494:pharmacology*; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D010766:Phosphorylation; D011869:Radioligand Assay; D013329:Structure-Activity Relationship
chemical_list: D018727:Muscarinic Antagonists; D002217:Carbachol; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3
keywords: Acetylcholine chloride (PubChem CID: 6060); Allosteric modulation; Atropine sulfate (PubChem CID: 64663); Bivalent ligand; Carbachol; Carbachol chloride (PubChem CID: 5831); Gallamine triethiodide (PubChem CID: 6172); Hexamethonium chloride (PubChem CID: 93550); Muscarinic acetylcholine receptor