| Assay Method Information | |
| | Inhibition Assay |
| Description: | Compounds were screened for their ability to inhibit ATR kinase using a radioactive-phosphate incorporation assay. Assays were carried out in a mixture of 50 mM Tris/HCl (pH 7.5), 10 mM MgCl2 and 1 mM DTT. Final substrate concentrations were 10 μM [γ-33P]ATP (3 mCi 33P ATP/mmol ATP, Perkin Elmer) and 800 μM target peptide (ASELPASQPQPFSAKKK (SEQ. ID NO: 1)).Assays were carried out at 25° C. in the presence of 5 nM full-length ATR. An assay stock buffer solution was prepared containing all of the reagents listed above, with the exception of ATP and the test compound of interest. 13.5 μL of the stock solution was placed in a 96 well plate followed by addition of 2 μL of DMSO stock containing serial dilutions of the test compound (typically starting from a final concentration of 15 μM with 3-fold serial dilutions) in duplicate (final DMSO concentration 7%). The plate was pre-incubated for 10 minutes at 25° C. and the reaction initiated by addition of 15 μL [γ-33P]ATP (final concentration 10 μM).The reaction was stopped after 24 hours by the addition of 30 μL 0.1M phosphoric acid containing 2 mM ATP. A multiscreen phosphocellulose filter 96-well plate (Millipore, Cat no. MAPHN0B50) was pretreated with 100 μL 0.2M phosphoric acid prior to the addition of 45 μL of the stopped assay mixture. The plate was washed with 5×200 μL 0.2M phosphoric acid. After drying, 100 μL Optiphase SuperMix liquid scintillation cocktail (Perkin Elmer) was added to the well prior to scintillation counting (1450 Microbeta Liquid Scintillation Counter, Wallac). |
| Affinity data for this assay | |
|---|---|
| If you find an error in this entry please send us an E-mail | |