Agonist activity at human NOP receptor expressed in HEK293 cell membranes assessed as stimulation of [35S]GTPgammaS binding at 10 uM relative to nociceptin
Agonist activity at human recombinant NOP receptor expressed in CHO cells co-expressing C-terminally modifed Gaqi5 protein by Fluo-4AM dye based calcium mobilization assay
Intrinsic activity at human recombinant NOP receptor expressed in CHO cells co-expressing C-terminally modifed Gaqi5 protein by Fluo-4AM dye based calcium mobilization assay
Antagonist activity at human recombinant NOP receptor expressed in CHO cells co-expressing C-terminally modifed Gaqi5 protein assessed as inhibition of agonist response by Fluo-4AM dye based calcium mobilization assay
Agonist activity at human recombinant NOP receptor expressed in CHO cells co-expressing C-terminally modifed Gaqi5 protein up to 10 uM by Fluo-4AM dye based calcium mobilization assay
Antagonist activity at human recombinant NOP receptor expressed in CHO cells co-expressing C-terminally modifed Gaqi5 protein assessed as inhibition of agonist response up to 10 uM by Fluo-4AM dye based calcium mobilization assay
Antagonist activity at human recombinant NOP receptor expressed in CHO cells co-expressing C-terminally modifed Gaqi5 protein assessed as inhibition of (R)-8-(Chroman-4-yl)-1-phenyl-1,3,8-triazaspiro[4.5]decan-4-one-induced response by Fluo-4AM dye based calcium mobilization assay
Antagonist activity at human recombinant NOP receptor expressed in CHO cells co-expressing C-terminally modifed Gaqi5 protein assessed as inhibition of (S)-8-(Chroman-4-yl)-1-phenyl-1,3,8-triazaspiro[4.5]decan-4-one-induced response by Fluo-4AM dye based calcium mobilization assay
Agonist activity at human recombinant NOP receptor expressed in CHO cells co-expressing C-terminally modifed Gaqi5 protein at EC80 level in presence of SB-612111 by Fluo-4AM dye based calcium mobilization assay
ORL-1 Receptor Binding Assay: Radioligand binding assays (screening and dose-displacement) used 0.1 nM [3H]-nociceptin (NEN; 87.7 Ci/mmole) with 10-20 μg membrane protein in a final volume of 500 μL binding buffer (10 mM MgCl2, 1 mM EDTA, 5% DMSO, 50 mM HEPES, pH 7.4). Non-specific binding was determined in the presence of 10 nM unlabeled nociceptin (American Peptide Company). All reactions were performed in 96-deep well polypropylene plates for 1 h at about 25° C. Binding reactions were terminated by rapid filtration onto 96-well Unifilter GF/C filter plates (Packard) presoaked in 0.5% polyethylenimine (Sigma). Harvesting was performed using a 96-well tissue harvester (Packard) followed by three filtration washes with 5004 ice-cold binding buffer. Filter plates were subsequently dried at 50° C. for 2-3 hours. Fifty μL/well scintillation cocktail (BetaScint; Wallac) was added and plates were counted in a Packard Top-Count for 1 min/well.
ORL-1 Receptor Binding Assay: ORL-1 Receptor Binding Assay Procedures: Membranes from recombinant HEK-293 cells expressing the human opioid receptor-like receptor (ORL-1) (Receptor Biology) were prepared by lysing cells in ice-cold hypotonic buffer (2.5 mM MgCl2, 50 mM HEPES, pH 7.4) (10mL/10 cm dish) followed by homogenization with a tissue grinder/Teflon pestle. Membranes were collected by centrifugation at 30,000×g for 15 min at 4° C. and pellets resuspended in hypotonic buffer to a final concentration 1-3mg/mL. Protein concentrations were determined using the BioRad protein assay reagent with bovine serum albumen as standard. Aliquots of the ORL-1 receptor membranes were stored at −80° C.
Radioligand Binding Assay: Radioligand dose-displacement binding assays for μ-opioid receptors used 0.2 nM[3H]-diprenorphine (NEN, Boston, Mass.), with 5-20 mg membrane protein/well in a final volume of 500 μl binding buffer (10 mM MgCl2, 1 mM EDTA, 5% DMSO, 50 mM HEPES, pH 7.4). Reactions were carried out in the absence or presence of increasing concentrations of unlabeled naloxone. All reactions were conducted in 96-deep well polypropylene plates for 1-2 hr at room temperature. Binding reactions were terminated by rapid filtration onto 96-well Unifilter GF/C filter plates (Packard, Meriden, Conn.) presoaked in 0.5% polyethylemimine using a 96-well tissue harvester (Brandel, Gaithersburg, Md.) followed by performing three filtration washes with 500 μl of ice-cold binding buffer. Filter plates were subsequently dried at 50° C. for 2-3 hours. BetaScint scintillation cocktail (Wallac, Turku, Finland) was added (50 μl/well), and plates were counted using a Packard Top-Count for 1 min/well.