Antagonist activity at recombinant human EP2 receptor expressed in CHO cells assessed as inhibition of PGE2-stimulated cAMP accumulation at 1 uM by scintillation proximity assay in presence of [125I]-cAMP
Agonist activity at recombinant human EP2 receptor expressed in CHO cells assessed as induction of cAMP accumulation at 1 uM after 15 mins by scintillation proximity assay in presence of [125I]-cAMP
Binding Assay: Measurement of EP2 receptor binding affinity was carried out according to the method of Abramovitz et al. (Biochimica et Biophysica Acta, 1483, 285 (2000)). A test compound dissolved in dimethylsulfoxide and [3H]PGE2 (NET-428, available from PerkinElmer Inc.) (final concentration: 10 nM) were added to a buffer solution (10 mM MES-KOH (pH 6.0), 10 mM MgCl2, 1 mM EDTA) in which 10 μg of a membrane fraction (ES-562-M, available from Euroscreen S.A.) of HEK293 cells expressing human EP2 receptor had been suspended, followed by incubation at 30° C. for 60 minutes. The membrane fraction was recovered on glass fiber filter paper (GF/B, available from Whatman PLC) using a cell harvester (M30R, available from Brandel Inc.), and after washing with a buffer solution (10 mM MES-KOH (pH 6.0), 10 mM MgCl2), radioactivity was measured with a liquid scintillation analyzer (2000CA, available from Packard).
In Vitro Binding Assay: hEP1 and hEP4 membranes are prepared from recombinant HEK293 cells stably expressing the human EP1 (Genbank accession number AY275470) or EP4 (Genbank accession number AY429109) receptors. hEP2 and hEP3 membranes are prepared from HEK293 cells transiently transfected with EP2 (Genbank accession number AY275471) or EP3 (isoform VI: Genbank accession number AY429108) receptor plasmids. Frozen cell pellets are homogenized in homogenization buffer using a Teflon/glass homogenizer. Membrane protein is aliquoted and quick frozen on dry ice prior to storage at -80 C. Homogenization buffer contained 10 mM Tris-HCl, pH 7.4, 250 mM sucrose, 1 mM EDTA, 0.3 mM indomethacin and plus Complete, with EDTA, obtained from Roche Molecular Biochemicals (Catalog Number 1 697 498).Kd values for [3]H-PGE2 binding to each receptor are determined by saturation binding studies or homologous competition. Compounds are tested in a 96-well format using a three-fold dilution series.
In Vitro Binding Assay: hEP1 and hEP4 membranes are prepared from recombinant HEK293 cells stably expressing human EP1 (Genbank accession number AY275470) or EP4 (Genbank accession number AY429109) receptors. hEP2 and hEP3 membranes are prepared from HEK293 cells transiently transfected with EP2 (Genbank accession number AY275471) or EP3 (isoform VI: Genbank accession number AY429108) receptor plasmids. Frozen cell pellets are homogenized in homogenization buffer using a Teflon/glass homogenizer. Membrane protein is aliquoted and quick frozen on dry ice prior to storage at -80 C. Homogenization buffer contained 10 mM Tris-HCl, pH 7.4, 250 mM sucrose, 1 mM EDTA, 0.3 mM indomethacin and plus Complete, with EDTA, obtained from Roche Molecular Biochemicals (Catalog Number 1 697 498). Kd values for [3H]-PGE2 binding to each receptor are determined by saturation binding studies or homologous competition. Compounds are tested in a 96-well format using a three-fold dilution series to generate a 10-point curve.
In Vitro Binding Assay: hEP1 and hEP4 membranes are prepared from recombinant HEK293 cells stably expressing the human EP1 (Genbank accession number AY275470) or EP4 (Genbank accession number AY429109) receptors. hEP2 and hEP3 membranes are prepared from HEK293 cells transiently transfected with EP2 (Genbank accession number AY275471) or EP3 (isoform VI: Genbank accession number AY429108) receptor plasmids. Frozen cell pellets are homogenized in homogenization buffer using a Teflon/glass homogenizer. Membrane protein is aliquoted and quick frozen on dry ice prior to storage at -80 C. Homogenization buffer contained 10 mM Tris-HCl, pH 7.4, 250 mM sucrose, 1 mM EDTA, 0.3 mM indomethacin and plus Complete, with EDTA, obtained from Roche Molecular Biochemicals (Catalog Number 1 697 498).Kd values for [3H]-PGE2 binding to each receptor are determined by saturation binding studies or homologous competition. Compounds are tested in a 96-well format using a three-fold dilution series.