Assay Method Information

Assay Name:  TR-FRET Screening
Description:  The compounds of the present application can regulate (inhibit) the biological activity of the nuclear receptor RORγ, and the intensity of such a regulation (inhibition) can be evaluated by TR-FRET (Time-Resolved Fluorescence Resonance Energy Transfer) screening system. Nuclear receptor cofactors (co-activators and co-repressors) can regulate the transcription of target genes through interactions with nuclear receptors. If a ligand (test compound) interferes with the interaction between a nuclear receptor and a cofactor, such a ligand (test compound) can regulate the transcription of the corresponding gene.The method employs LanthaScreen TR-FRET (Time-Resolved Fluorescence Resonance Energy Transfer) technique of Life Technologies Co. to test the compounds for their abilities to regulate (agonize or inversely agonize) the interaction between RORγ and its co-activator. RORγ-LBD is indirectly labeled by binding a terbium(Tb)-labeled anti-GST antibody (Life Technologies #PV3550) onto the GST tag of RORγ-LBD (Life Technologies #PV5887). When no ligand is present, RORγ can continuously bind to a fluorescein-labeled co-activator, and the binding of an agonist to RORγ can enhance the interaction between RORγ and the fluorescein-labeled co-activator; while the binding of an inverse agonist to RORγ can inhibit the interaction between RORγ and the fluorescein-labeled co-activator. When the fluorescein-labeled co-activator and the terbium-labeled anti-GST antibody-RORγ-LBD composite are close to each other to a certain distance, an energy transfer can occur, generating a TR-FRET signal. The co-activators employed in the method are not limited to D22 (Life Technologies #PV4386).(1) The final concentrations in the reaction system and the reaction conditions in the method are shown in the table below:TABLE 2 Concentration of Total Concentration of Fluorescein-labeled Concentration of Tb-labeled volume Reaction ROR γ-LBD co-activator activator peptide anti-GST antibody (μL) conditions 2 nM D22 150 nM 2 nM 20 22° C., 5 hr Fluorescein-D22
Affinity data for this assay
 

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