Solubilization of rat brain phencyclidine receptors in an active binding form that is sensitive to N-methyl-D-aspartate receptor ligands.
Phencyclidine (PCP) receptors were successfully solubilized from rat forebrain membranes with 1% sodium cholate. Approximately 58% of the initial protein and 20-30% of the high-affinity PCP binding sites were solubilized. The high affinity toward PCP-like drugs, the stereo-selectivity of the sites, and the sensitivity to N-methyl-D-aspartate (NMDA) receptor ligands were preserved. Binding of the potent PCP receptor ligand N-[3H][1-(2-thienyl)cyclohexyl] piperidine ([3H]TCP) to the soluble receptors was saturable (KD = 35 nM), and PCP-like drugs inhibited [3H]TCP binding in a rank order of potency close to that observed for the membrane-bound receptors; the most potent inhibitors were TCP (Ki = 31 nM) and the anticonvulsant MK-801 (Ki = 50 nM). The NMDA receptor antagonist 2-amino-5-phosphonovaleric acid inhibited binding of [3H]TCP to the soluble receptors; glutamate or NMDA diminished this inhibition in a dose-dependent manner. Taken together, the results indicate that the soluble PCP receptor preparation contains the glutamate recognition sites and may represent a single receptor complex for PCP and NMDA, as suggested by electrophysiological data. The successful solubilization of the PCP receptors in an active binding form should now facilitate their purification.
D015763:2-Amino-5-phosphonovalerate; D000818:Animals; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D001667:Binding, Competitive; D001923:Brain Chemistry; D002462:Cell Membrane / Q000032:analysis; D019826:Cholic Acid; D002793:Cholic Acids / Q000494:pharmacology; D003902:Detergents / Q000494:pharmacology; D005971:Glutamates / Q000378:metabolism; D018698:Glutamic Acid; D008297:Male; D016202:N-Methylaspartate; D010622:Phencyclidine / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000378:metabolism*; D017478:Receptors, Phencyclidine; D012995:Solubility; D014633:Valine / Q000031:analogs & derivatives / Q000494:pharmacology
D002793:Cholic Acids; D003902:Detergents; D005971:Glutamates; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter; D017478:Receptors, Phencyclidine; D001224:Aspartic Acid; D018698:Glutamic Acid; D016202:N-Methylaspartate; D015763:2-Amino-5-phosphonovalerate; C012058:tenocyclidine; D019826:Cholic Acid; D014633:Valine; D010622:Phencyclidine