CHEMBL5738411

ROCK Kinase Inhibition Assays: All compounds were initially prepared as 10 mM stocks in anhydrous dimethylsulfoxide (DMSO). A 20 μl aliquot of the 10 mM solutions was transferred to individual wells in column 1 of a 96-well polypropylene microtiter plate (Corning #3363) and diluted with DMSO to give a final compound concentration of 4 mM. Test compounds were then serially diluted 1:5 in DMSO for an 11-point concentration response and further diluted in the assay buffer bringing all compound concentrations to a final range of 100 μM to 10 pM in 2.5% DMSO. The assay was performed in white 96-well, flat-bottom, half-area, non-binding assay plate (Corning #3642) in assay buffer consisting of 20 mM HEPES (pH 7.5), 10 mM MgCl2*6H2O, 100 μM sodium orthovanadate, 0.05% CHAPS and 0.1% bovine serum albumin. A 10 μL aliquot of compound from each well of the intermediate dilution plate and 20 μL of a 2× substrate/enzyme solution containing acceptor substrate (800 nM RSK2 peptide KRRRLSSLRA (SEQ ID NO: 1)), ROCK2 enzyme (10 nM), or ROCK1 enzyme, and 1,4-Dithiothreitol (DTT, 2 μM) were added to all wells. The reaction was initiated by the addition of 10 μL of 4× stock solution ATP (2 ∥M). Reactions were thoroughly mixed manually, covered and allowed to incubate at room temperature for 75 min. Protein kinase activity was quantitated using Promega's KINASE-GLO™ luminescent Kinase Assay Kit according to the manufacturer's directions. ATP concentrations remaining in Test wells following the termination of the enzymatic reaction were compared against control wells containing equivalent amounts of DMSO containing no inhibitor (CTRL). ATP concentrations in both Test wells and CTRL wells were normalized against background (BKG) ATP concentrations in wells containing concentrations of inhibitor that completely inhibited the protein kinase under investigation (i.e. a concentration that prevented any consumption of ATP over the course of the incubation). Percent of Control (POC) values were determined for each concentration of compound tested according to the equation: POC=((Test well value−BKG)/(CTRL−BKG))*100IC50 values were calculated using the following 4-parameter logistic curve-fitting algorithm: f(x)=(A+((B−A)/(1+((x/C){circumflex over ( )}D))))IC50 values were converted to Ki values using the Cheng-Prusoff Equation: Ki=IC50/(1+([ATP]/Km ATP])).