CHEMBL5736022

Inhibitory Activity Assay: Poly(Glu, Tyr) 4:1 as a substrate for enzyme catalyzed reaction was diluted with potassium-free PBS (10 mM sodium phosphate buffer, 150 mM NaCl, pH 7.2-7.4) to g/mL to coat a ELISA plate. The plate was cultured at 37° C. for 12-16 h, washed with 200 μL/well of T-PBS (PBS containing 0.1% of Tween-20) three times, and dried in an oven at 37° C. for 1-2 h. Into the above ELISA plate coated with the substrate, an ATP solution diluted with a reaction buffer (50 mM HEPES, pH 7.4, 50 mM MgCl2, 5 mM MnCl2, 0.2 mM Na3VO4, 1 mM DTT) was first added at 50 μL/well (concentration of 10 μM). Then, a test compound diluted by 1% DMSO to a suitable concentration was added (10 μL/well), and negative control well and positive compound control well were provided separately. Finally, the reaction was initiated by adding BTK tyrosine kinase protein diluted in 40 μL of reaction buffer.The above reaction system was placed on a shaker (100 rpm) at 37° C. for 1 h, then washed with T-PBS for three times, primary antibody PY99 (Cell Signaling Technology) was added at 100 μL/well, and the reaction was conducted on the shaker at 37° C. for 0.5 h. After the plate was washed with T-PBS, secondary antibody horseradish peroxidase-labeled goat anti-mouse IgG was added at 100 μL/well, and the reaction was conducted on the shaker at 37° C. for 0.5 h. After the plate was washed with T-PBS, 2 mg/mL of OPD developing solution was added at 100 μL/well, and the reaction was conducted in the dark at 25° C. for 1 to 10 minutes. Then the reaction was quenched by adding 2 M H2SO4 at 50 μL/well. The data were read on a wavelength-tunable microplate reader ELISA SPECTRA MAX 190 at a wavelength of 490 nm.