CHEMBL3889102

Kinase Binding Assay: PIM-1, -2, and -3 enzymes were generated as fusion proteins expressed in bacteria and purified by IMAC column chromatography (Sun, X., Chiu, J. F., and He, Q. Y. (2005) Expert Rev. Proteomics, 2:649-657). A fluorescent-labeled Pim-specific peptide substrate, was custom synthesized by American Peptide Company (Sunnyvale, Calif.). Reaction Buffer contained 10 mM HEPES, pH 7.2, 10 mM MgCl2, 0.01% Tween 20, 2 mM DTT. Termination Buffer contained 190 mM HEPES, pH 7.2, 0.015% Brij-35, 0.2% Coating Reagent 3 (Caliper Life Sciences, Hopkinton, Mass.), 20 mM EDTA. Separation Buffer contained 100 mM HEPES, pH 7.2, 0.015% Brij-35, 0.1% Coating Reagent 3, 1:200 Coating Reagent 8 (Caliper Life Sciences, Hopkinton, Mass.), 10 mM EDTA and 5% DMSO.PIM reactions were carried out in a final volume of 10 uL per well in a 384-well plate. A standard enzymatic reaction, initiated by the addition of 5 uL 2ÿ¿ATP and test compound to 5 uL of 2x enzyme and FAM-peptide, contained 20 uM PIM1, 50 uM PIM2, or 55 uM PIM3, 1 uM FAM-peptide, and 10 uM ATP, in Reaction Buffer. After 90 minutes of incubation at room temperature, the phosphorylation reaction was stopped by the addition of 10 uL Termination Buffer. The product and substrate in each independent reaction were separated on a 12-sipper microfluidic chip (Caliper Life Sciences, Hopkinton, Mass.) run on a Caliper LC3000 (Caliper Life Sciences, Hopkinton, Mass.). The separation of product and substrate was optimized by choosing voltages and pressure using Caliper's Optimizer software (Hopkinton, Mass.). The separation conditions used a downstream voltage of -500V, an upstream voltage of -2150V, and a screening pressure of -1.2 psi. The product and substrate fluorophore were excited at 488 nm and detected at 530 nm. Substrate conversion was calculated from the electropherogram using HTS Well Analyzer software (Caliper Life Sciences, Hopkinton, Mass.). Ki values for the test compound were calculated.