title: Binding Mode Selection Determines the Action of Ecstasy Homologs at Monoamine Transporters.
abstract: Determining the structural elements that define substrates and inhibitors at the monoamine transporters is critical to elucidating the mechanisms underlying these disparate functions. In this study, we addressed this question directly by generating a series of N-substituted 3,4-methylenedioxyamphetamine analogs that differ only in the number of methyl substituents on the terminal amine group. Starting with 3,4-methylenedioxy-N-methylamphetamine, 3,4-methylenedioxy-N,N-dimethylamphetamine (MDDMA) and 3,4-methylenedioxy-N,N,N-trimethylamphetamine (MDTMA) were prepared. We evaluated the functional activities of the compounds at all three monoamine transporters in native brain tissue and cells expressing the transporters. In addition, we used ligand docking to generate models of the respective protein-ligand complexes, which allowed us to relate the experimental findings to available structural information. Our results suggest that the 3,4-methylenedioxyamphetamine analogs bind at the monoamine transporter orthosteric binding site by adopting one of two mutually exclusive binding modes. 3,4-methylenedioxyamphetamine and 3,4-methylenedioxy-N-methylamphetamine adopt a high-affinity binding mode consistent with a transportable substrate, whereas MDDMA and MDTMA adopt a low-affinity binding mode consistent with an inhibitor, in which the ligand orientation is inverted. Importantly, MDDMA can alternate between both binding modes, whereas MDTMA exclusively binds to the low-affinity mode. Our experimental results are consistent with the idea that the initial orientation of bound ligands is critical for subsequent interactions that lead to transporter conformational changes and substrate translocation.
authors.affiliation: Institute of Pharmacology, Center for Physiology and Pharmacology (W.S., T.Sto., P.S.H., M.H., T.Ste., H.H.S.) and Center for Addiction Research and Science (H.H.S.), Medical University of Vienna, Vienna, Austria; Designer Drug Research Unit (J.S.P., M.H.B.) and Medicinal Chemistry Section (J.J.C., A.H.N.), Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland; Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria (A.S., G.F.E.); and Department of Pharmacology, Yale University, New Haven, Connecticut (Y.-W.Z., G.R.).
authors.forename: Walter
authors.initials: W
authors.lastname: Sandtner
authors.affiliation: Institute of Pharmacology, Center for Physiology and Pharmacology (W.S., T.Sto., P.S.H., M.H., T.Ste., H.H.S.) and Center for Addiction Research and Science (H.H.S.), Medical University of Vienna, Vienna, Austria; Designer Drug Research Unit (J.S.P., M.H.B.) and Medicinal Chemistry Section (J.J.C., A.H.N.), Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland; Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria (A.S., G.F.E.); and Department of Pharmacology, Yale University, New Haven, Connecticut (Y.-W.Z., G.R.).
authors.forename: Thomas
authors.initials: T
authors.lastname: Stockner
authors.affiliation: Institute of Pharmacology, Center for Physiology and Pharmacology (W.S., T.Sto., P.S.H., M.H., T.Ste., H.H.S.) and Center for Addiction Research and Science (H.H.S.), Medical University of Vienna, Vienna, Austria; Designer Drug Research Unit (J.S.P., M.H.B.) and Medicinal Chemistry Section (J.J.C., A.H.N.), Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland; Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria (A.S., G.F.E.); and Department of Pharmacology, Yale University, New Haven, Connecticut (Y.-W.Z., G.R.).
authors.forename: Peter S
authors.initials: PS
authors.lastname: Hasenhuetl
authors.affiliation: Institute of Pharmacology, Center for Physiology and Pharmacology (W.S., T.Sto., P.S.H., M.H., T.Ste., H.H.S.) and Center for Addiction Research and Science (H.H.S.), Medical University of Vienna, Vienna, Austria; Designer Drug Research Unit (J.S.P., M.H.B.) and Medicinal Chemistry Section (J.J.C., A.H.N.), Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland; Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria (A.S., G.F.E.); and Department of Pharmacology, Yale University, New Haven, Connecticut (Y.-W.Z., G.R.).
authors.forename: John S
authors.initials: JS
authors.lastname: Partilla
authors.affiliation: Institute of Pharmacology, Center for Physiology and Pharmacology (W.S., T.Sto., P.S.H., M.H., T.Ste., H.H.S.) and Center for Addiction Research and Science (H.H.S.), Medical University of Vienna, Vienna, Austria; Designer Drug Research Unit (J.S.P., M.H.B.) and Medicinal Chemistry Section (J.J.C., A.H.N.), Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland; Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria (A.S., G.F.E.); and Department of Pharmacology, Yale University, New Haven, Connecticut (Y.-W.Z., G.R.).
authors.forename: Amir
authors.initials: A
authors.lastname: Seddik
authors.affiliation: Institute of Pharmacology, Center for Physiology and Pharmacology (W.S., T.Sto., P.S.H., M.H., T.Ste., H.H.S.) and Center for Addiction Research and Science (H.H.S.), Medical University of Vienna, Vienna, Austria; Designer Drug Research Unit (J.S.P., M.H.B.) and Medicinal Chemistry Section (J.J.C., A.H.N.), Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland; Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria (A.S., G.F.E.); and Department of Pharmacology, Yale University, New Haven, Connecticut (Y.-W.Z., G.R.).
authors.forename: Yuan-Wei
authors.initials: YW
authors.lastname: Zhang
authors.affiliation: Institute of Pharmacology, Center for Physiology and Pharmacology (W.S., T.Sto., P.S.H., M.H., T.Ste., H.H.S.) and Center for Addiction Research and Science (H.H.S.), Medical University of Vienna, Vienna, Austria; Designer Drug Research Unit (J.S.P., M.H.B.) and Medicinal Chemistry Section (J.J.C., A.H.N.), Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland; Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria (A.S., G.F.E.); and Department of Pharmacology, Yale University, New Haven, Connecticut (Y.-W.Z., G.R.).
authors.forename: Jianjing
authors.initials: J
authors.lastname: Cao
authors.affiliation: Institute of Pharmacology, Center for Physiology and Pharmacology (W.S., T.Sto., P.S.H., M.H., T.Ste., H.H.S.) and Center for Addiction Research and Science (H.H.S.), Medical University of Vienna, Vienna, Austria; Designer Drug Research Unit (J.S.P., M.H.B.) and Medicinal Chemistry Section (J.J.C., A.H.N.), Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland; Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria (A.S., G.F.E.); and Department of Pharmacology, Yale University, New Haven, Connecticut (Y.-W.Z., G.R.).
authors.forename: Marion
authors.initials: M
authors.lastname: Holy
authors.affiliation: Institute of Pharmacology, Center for Physiology and Pharmacology (W.S., T.Sto., P.S.H., M.H., T.Ste., H.H.S.) and Center for Addiction Research and Science (H.H.S.), Medical University of Vienna, Vienna, Austria; Designer Drug Research Unit (J.S.P., M.H.B.) and Medicinal Chemistry Section (J.J.C., A.H.N.), Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland; Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria (A.S., G.F.E.); and Department of Pharmacology, Yale University, New Haven, Connecticut (Y.-W.Z., G.R.).
authors.forename: Thomas
authors.initials: T
authors.lastname: Steinkellner
authors.affiliation: Institute of Pharmacology, Center for Physiology and Pharmacology (W.S., T.Sto., P.S.H., M.H., T.Ste., H.H.S.) and Center for Addiction Research and Science (H.H.S.), Medical University of Vienna, Vienna, Austria; Designer Drug Research Unit (J.S.P., M.H.B.) and Medicinal Chemistry Section (J.J.C., A.H.N.), Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland; Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria (A.S., G.F.E.); and Department of Pharmacology, Yale University, New Haven, Connecticut (Y.-W.Z., G.R.).
authors.forename: Gary
authors.initials: G
authors.lastname: Rudnick
authors.affiliation: Institute of Pharmacology, Center for Physiology and Pharmacology (W.S., T.Sto., P.S.H., M.H., T.Ste., H.H.S.) and Center for Addiction Research and Science (H.H.S.), Medical University of Vienna, Vienna, Austria; Designer Drug Research Unit (J.S.P., M.H.B.) and Medicinal Chemistry Section (J.J.C., A.H.N.), Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland; Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria (A.S., G.F.E.); and Department of Pharmacology, Yale University, New Haven, Connecticut (Y.-W.Z., G.R.).
authors.forename: Michael H
authors.initials: MH
authors.lastname: Baumann
authors.affiliation: Institute of Pharmacology, Center for Physiology and Pharmacology (W.S., T.Sto., P.S.H., M.H., T.Ste., H.H.S.) and Center for Addiction Research and Science (H.H.S.), Medical University of Vienna, Vienna, Austria; Designer Drug Research Unit (J.S.P., M.H.B.) and Medicinal Chemistry Section (J.J.C., A.H.N.), Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland; Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria (A.S., G.F.E.); and Department of Pharmacology, Yale University, New Haven, Connecticut (Y.-W.Z., G.R.).
authors.forename: Gerhard F
authors.initials: GF
authors.lastname: Ecker
authors.affiliation: Institute of Pharmacology, Center for Physiology and Pharmacology (W.S., T.Sto., P.S.H., M.H., T.Ste., H.H.S.) and Center for Addiction Research and Science (H.H.S.), Medical University of Vienna, Vienna, Austria; Designer Drug Research Unit (J.S.P., M.H.B.) and Medicinal Chemistry Section (J.J.C., A.H.N.), Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland; Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria (A.S., G.F.E.); and Department of Pharmacology, Yale University, New Haven, Connecticut (Y.-W.Z., G.R.).
authors.forename: Amy Hauck
authors.initials: AH
authors.lastname: Newman
authors.affiliation: Institute of Pharmacology, Center for Physiology and Pharmacology (W.S., T.Sto., P.S.H., M.H., T.Ste., H.H.S.) and Center for Addiction Research and Science (H.H.S.), Medical University of Vienna, Vienna, Austria; Designer Drug Research Unit (J.S.P., M.H.B.) and Medicinal Chemistry Section (J.J.C., A.H.N.), Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland; Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria (A.S., G.F.E.); and Department of Pharmacology, Yale University, New Haven, Connecticut (Y.-W.Z., G.R.) harald.sitte@meduniwien.ac.at.
authors.forename: Harald H
authors.identifier: http://orcid.org/0000-0002-1339-7444
authors.initials: HH
authors.lastname: Sitte
mesh_terms: D000818:Animals; D001665:Binding Sites / Q000502:physiology; D001692:Biological Transport / Q000502:physiology; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D008297:Male; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000737:chemistry* / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D051381:Rats; D017207:Rats, Sprague-Dawley; D050493:Vesicular Monoamine Transport Proteins / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D050493:Vesicular Monoamine Transport Proteins; D018817:N-Methyl-3,4-methylenedioxyamphetamine