CHEMBL5738014

ROCK1 and ROCK2 Compound Selectivity: Dose response curves for Rho-kinase inhibition were derived from a Invitrogen Z′-LYTE™ Kinase Assay Kit (Invitrogen catalog number PV3793). Purified active ROCK1 and ROCK2 were obtained from Invitrogen (catalog numbers ROCK1, PV3691 and ROCK2, PV3759). The kit components include a coumarin and fluorescein labeled peptide based on myosin light chain 2 (KKRPQRRYSNVF), a proprietary protease containing development reagent and a proprietary Stop buffer used to terminate the development reaction. The inhibitory activities of compounds are measured according to the manufactures protocol. Briefly, decreasing concentrations of test compounds or the known ROCK inhibitor Y-27963, are added, from 10 uM to 2.56×10−5 uM to reaction buffer containing 50 mM HEPES pH 7.5, 10 mM MgCl2, 5 mM EGTA, and 0.05% Brij-35 and of ROCK1 at 0.18 ug/mL or ROCK2 at 0.8 ug/mL in assay dilution buffer. This mixture is overlayed into a white 96-well half area plate and the reaction is initiated with the addition of 5 uM ATP for ROCK1 or 12 uM ATP for ROCK2. The assay proceeds at room temperature for 1 hour followed by the addition of development reagent, and further incubation for 1 hour at room temperature. STOP reagent is then added and the reaction and immediately the coumarin and fluorescein emission signals are read on a Tecan Infinite M1000 fluorescence plate reader (excitation: 400 nm; emission 445 and 520 nm, respectively). By comparing the emission ratios of the test samples against control samples, percent phosphorylation values are calculated and the concentration of inhibitor that produces ½ inhibition of kinase activity (IC50) is determined using Prism.