title: Docking analyses on human muscarinic receptors: unveiling the subtypes peculiarities in agonists binding.
abstract: The study presents a docking analysis for the interaction capabilities of some muscarinic receptors (i.e., M(1), M(2), and M(5)) whose full-length models were previously generated by us. In detail, the docking simulations involved a dataset of 30 agonists, taken from the literature, including a first series of oxathiolane/dioxolane congeners and a second subset of more heterogeneous ligands. The obtained results unveil that it is possible to discriminate among the binding modes of considered muscarinic receptors, developing specific interaction patterns which are significantly different for the arrangement of both polar and hydrophobic interactions. Thus, the M(1) subtype possesses the widest binding site, while the M(2) receptor is characterized by a large but asymmetric region that accommodates the ligand's ammonium head and finally the M(5) binding site is quite similar to that of M(2) subtype being univocally characterized by a second aspartate residue which interacts with the ammonium head. The significant correlations between docking scores and affinity values afford an encouraging validation for the reported binding modes and confirm the key role of molecular flexibility in the ligand recognition of muscarinic receptors.
authors.affiliation: Istituto di Chimica Farmaceutica e Tossicologica "Pietro Pratesi", Università di Milano, Via Mangiagalli, 25 I-20133 Milano, Italy. giulio.vistoli@unimi.it
authors.forename: Giulio
authors.initials: G
authors.lastname: Vistoli
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pedretti
authors.forename: Silvia
authors.initials: S
authors.lastname: Dei
authors.forename: Serena
authors.initials: S
authors.lastname: Scapecchi
authors.forename: Cristina
authors.initials: C
authors.lastname: Marconi
authors.forename: Maria Novella
authors.initials: MN
authors.lastname: Romanelli
mesh_terms: D001665:Binding Sites; D003198:Computer Simulation; D006801:Humans; D008024:Ligands; D018721:Muscarinic Agonists / Q000737:chemistry*; D011485:Protein Binding; D043643:Receptor, Muscarinic M1; D043585:Receptor, Muscarinic M2; D043642:Receptor, Muscarinic M5; D011976:Receptors, Muscarinic / Q000737:chemistry*
chemical_list: D008024:Ligands; D018721:Muscarinic Agonists; D043643:Receptor, Muscarinic M1; D043585:Receptor, Muscarinic M2; D043642:Receptor, Muscarinic M5; D011976:Receptors, Muscarinic