CHEMBL5739455

Biological Assay: ATM: Recombinant, full length human FLAG-tagged ATM activity (Eurofins 14-933) was measured in an ELISA for p53 S15 phosphorylation, in a 384 well V-bottom polypropylene plate (Greiner Bio One 781280). Reactions contained 0.75 nM ATM, 25 nM full length myc tagged p53 (Eurofins 23-034), 10 μM UltraPure ATP (Promega V915B) and serial dilutions of inhibitors (0.1% DMSO final) in 25 mM HEPES, pH 7.5. 5 mM MgCl2, 2.5 mM MnCl2, 0.006% Brij-35, 0.5% glycerol, 0.1 mg/ml BSA, 0.5 mM DTT and were allowed to proceed for 30 min at 20° C. 70 mM EDTA final terminated the kinase reactions. An aliquot of the terminated reaction (25 μl) was transferred to a 384-well, high binding microplate (Greiner Bio One 781061), precoated with anti-myc capture antibody overnight (Millipore 05-724) diluted in 1:1000 in PBS, then blocked with Odyssey blocking buffer (LI-COR Biosciences 92740000) for 60 min at 20° C. The terminated reaction was allowed to capture for 2 h at 20° C. Phosphorylation was measured using an antibody specific to p53 S15 phosphorylation (1:5000 Abcam ab38497), anti-rabbit HRP (1:1000 Cell Signalling Technology, 7074) and TMB (ab171522). Antibodies were diluted in Odyssey blocking buffer and incubated for 60 min at 20° C. Three washes with PBS containing 0.05% (v/v) Tween 20 (PBS-T) were performed between each incubation. The TMB reaction was stopped with an equal volume of 0.2 M sulfuric acid and absorbance read at 450 nm on the Perkin Elmer Envision within 30 min of terminating the reaction. The percentage of inhibition was calculated for each concentration of compound using 0.1% DMSO control wells as 0% inhibition and 1 μM KU60019 as 100% inhibition.