CHEMBL5733332

Fluorescent Polarization Binding (FP Binding) assay: Test compounds were diluted in DMSO and 0.1 μL of solution was dispensed to each well of a 384-well white solid microplate. The assay buffer was 50 mM HEPES pH 7.5, 50 mM NaCl, 30 mM MgCl2. The buffer was supplemented with 0.02% CHAPS, 0.01% of Pluronic F127, 0.1 mg/mL BSA and 1 mM DTT. MnCl2, 5 mM, was included in the assay buffer on the day of the experiment. The enzymatic reaction comprised 1.5 μg/mL GST-hRIPK1 (8-327) and 50 μM ATP for receptor interacting protein kinase 1 and 15 μM ATP. 5 μL of enzyme and 5 μL of ATP were added to the plate at twice the final assay concentration and incubated at room temperature for 3 hours. Following this reaction, 10 μL of ADP-Glo reagent (Promega) was added to each well and incubated for 40 min at room temperature. This stops the kinase reaction and depletes any remaining ATP. 20 μL of ADP-Glo detection reagent was then added to each well and incubated at room temperature for at least 15 minutes. The detection reagent converts ADP to ATP and introduces luciferase and luciferin to detect ATP. The luminescence is then measured with the Envision (PerkinElmer) plate reader. Test compound inhibition was expressed as percent inhibition of internal assay controls. For concentration response curves, normalized data is fit and IC50 determined using XL-fit (IDBS) for Excel. The IC50 were averaged to determine a mean value, for a minimum of two independent experiments.