CHEMBL5734003

Enzyme Inhibition Assay: p38 MAPKα: The enzyme inhibitory activities of compounds disclosed herein were determined by FRET using synthetic peptides labelled with both donor and acceptor fluorophores (Z-LYTE, Invitrogen Ltd., Paisley, UK). The inhibitory activities of test compounds against the p38 MAPKα isoform (MAPK14: Invitrogen), were evaluated indirectly by determining the level of activation/phosphorylation of the down-stream molecule, MAPKAP-K2. The p38 MAPKα protein (80 ng/mL, 2.5 μL) was mixed with the test compound (2.5 μL of either 4 μg/mL, 0.4 μg/mL, 0.04 μg/mL or 0.004 μg/mL) for 2 hr at RT. The mix solution (2.5 μL) of the p38a inactive target MAPKAP-K2 (Invitrogen, 600 ng/mL) and FRET peptide (8 μM; a phosphorylation target for MAPKAP-K2) was then added and the kinase reaction was initiated by adding ATP (40 μM, 2.5 μL). The mixture was incubated for 1 hr at RT. Development reagent (protease, 5 μL) was added for 1 hr prior to detection in a fluorescence microplate reader (Varioskan® Flash, ThermoFisher Scientific).