CHEMBL5737228

Enzyme Assay: The ability of the receptor interacting protein kinase (RIPK1) to catalyze the hydrolysis of adenosine-5′-triphosphate (ATP) is monitored using the Transcreener ADP (adenosine-5′-diphosphate) assay (BellBrook Labs). Purified human RIP1 kinase domain (2-375) (50 nM) derived from a baculovirus-infected insect cell expression system is incubated with test compounds for 2 hours in 50 mM Hepes buffer (pH 7.5) containing 30 mM MgCl2, 1 mM dithiothreitol, 50 μM ATP, 0.002% Brij-35, and 0.5% dimethyl sulfoxide (DMSO). Reactions are quenched by the addition of 1× Bell Brooks Stop buffer B (20 mM Hepes (ph 7.5), 40 mM ethylenediaminetetraacetic acid and 0.02% Brij-35) containing an additional 12 mM EDTA and 55 ug/mL ADP2 antibody and 4 nM ADP-AlexaFluor® 633 tracer. The tracer bound to the antibody is displaced by the ADP generated during the RIP1K reaction, which causes a decrease in fluorescence polarization that is measured by laser excitation at 633 nm with a FP microplate reader M1000.