title: A novel photoaffinity ligand for the phencyclidine site of the N-methyl-D-aspartate receptor labels a Mr 120,000 polypeptide.
abstract: A radiolabeled photoaffinity ligand has been developed for the N-methyl-D-aspartate (NMDA)-preferring excitatory amino acid receptor complex. [3H]3-Azido-(5S, 10R)(+)-5-methyl-10,11-dihydro-5H- dibenzo[a,d]cyclohepten-5,10-imine [3H]3-azido-MK-801 demonstrated nearly identical affinity, density of binding sites, selectivity, pH sensitivity, and pharmacological profile in reversible binding assays with guinea pig brain homogenates to those displayed by its parent compound, MK-801. When employed in a photo-labeling protocol designed to optimize specific incorporation, [3H]3-azido-MK-801 labeled a single protein band which migrated in sodium dodecyl sulfate-polyacrylamide gels with Mr = 120,000. Incorporation of tritium into this band was completely inhibited when homogenates and [3H]3-azido-MK-801 were coincubated with 10 microM phencyclidine. These data suggest that the phencyclidine site of the NMDA receptor complex is at least in part comprised of a Mr = 120,000 polypeptide.
authors.affiliation: Vollum Institute, Oregon Health Sciences University, Portland 97201.
authors.forename: M S
authors.initials: MS
authors.lastname: Sonders
authors.forename: P
authors.initials: P
authors.lastname: Barmettler
authors.forename: J A
authors.initials: JA
authors.lastname: Lee
authors.forename: Y
authors.initials: Y
authors.lastname: Kitahara
authors.forename: J F
authors.initials: JF
authors.lastname: Keana
authors.forename: E
authors.initials: E
authors.lastname: Weber
mesh_terms: D000345:Affinity Labels / Q000378:metabolism*; D000818:Animals; D001386:Azides / Q000138:chemical synthesis / Q000378:metabolism*; D001665:Binding Sites; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D003986:Dibenzocycloheptenes / Q000138:chemical synthesis / Q000378:metabolism*; D016291:Dizocilpine Maleate / Q000031:analogs & derivatives*; D006168:Guinea Pigs; D007700:Kinetics; D008024:Ligands; D046911:Macromolecular Substances; D008970:Molecular Weight; D010622:Phencyclidine / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter / Q000302:isolation & purification / Q000378:metabolism* / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D000345:Affinity Labels; D001386:Azides; D003986:Dibenzocycloheptenes; D008024:Ligands; D046911:Macromolecular Substances; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter; C063752:3-azido-5-methyl-10,11-dihydro-5H-dibenzo(a,d)cyclohepten-5,10-imine; D016291:Dizocilpine Maleate; D010622:Phencyclidine