CHEMBL5733191

TR-FRET assay: DLK kinase reactions (20 μL) containing 5 nM N-terminally GST-tagged DLK (catalytic domain amino acid 1-520) (Carna Bioscience), 40 nM N-terminally HIS-tagged MKK4 K131M substrate, and 30 μM ATP in kinase reaction buffer (50 mM HEPES, pH 7.5, 0.01% Triton X-100, 0.01% Bovine γ-Globulins, 2 mM DTT, 10 mM MgCl2 and 1 mM EGTA), and testing compound 1:3 serial diluted starting at 20 uM were incubated at ambient temperature for 60 minutes in 384 well OptiPlate (Perkin Elmer). To quench kinase reactions and detect phosphorylated MKK4, 15 μL of TR-FRET antibody mixture containing 2 nM anti-phosphorylated MKK4 labeled with Europium cryptate (Cisbio) and 23 nM anti-HIS labeled with D2 (Cisbio) in detection buffer (25 mM Tris pH 7.5, 100 mM NaCl, 100 mM EDTA, 0.01% Tween-20, and 200 mM KF) was added to the reaction mixture. The detection mixture was incubated for 3 hours at ambient temperature and the TR-FRET was detected with an EnVision multilabel plate reader (Perkin-Elmer) using the LANCE/DELFIA Dual Enh label from Perkin-Elmer (excitation filter: UV2 (TRF) 320 and emission filters: APC 665 and Europium 615).