CHEMBL3889132

Kinase HotSpotâ¿¢ Assay: Compounds were profiled for FGFR inhibition activity at Reaction Biology Corporation (Malvern, Pa.) with their Kinase HotSpot assay. See, Anastassiadis et al., 2011, Comprehensive assay of kinase catalytic activity reveals features of kinase inhibitor selectivity. Nat Biotechnol 29, 1039-1045.Recombinant FGFR1 (2.5 nM), FGFR2 (1 nM), FGFR3 (5 nM), or FGFR4 (12 nM) (Invitrogen) was prepared as a mixture with substrate KKKSPGEYVNIEFG (SEQ ID NO:1) (20 uM, FGFR1 substrate); and Poly [E,Y]4:1 (0.2 mg/ml, FGFR2,3,4 substrate)] in kinase reaction buffer (20 mM HEPES-HCl, pH 7.5, 10 mM MgCl2, 2 mM MnCl2, 1 mM EGTA, 0.02% Brij35, 0.1 mM Na3VO4, 0.02 mg/ml BSA, 2 mM DTT, and 1% DMSO). Compound was added to the enzyme/substrate mixture using acoustic technology (Labcyte Echo 550, Sunnyvale, Calif.) (see, Olechno et al., 2006, Improving IC50 results with acoustic droplet ejection. JALA 11, 240-246) and pre-incubated for 0, 15, or 60 minutes at room temperature. After compound pre-incubation, a mixture of ATP (Sigma-Aldrich) and 33P-γ-ATP (PerkinElmer) was added to a final concentration of 10 uM to initiate kinase reactions. Reactions were incubated for 120 minutes at room temperature and then spotted onto Whatman P81 ion exchange filter paper. Unbound phosphate was removed by extensively washing filters in 0.75% phosphoric acid. See, Anastassiadis et al., 2011, Comprehensive assay of kinase catalytic activity reveals features of kinase inhibitor selectivity. Nat Biotechnol 29, 1039-1045.