CHEMBL5733418

In Vitro Enzyme Inhibition Assay: The ability of test compounds to inhibit the activity of Jarid1B was determined in 384-well plate format under the following reaction conditions: 0.8 nM Jarid1B, 300 nM H3K4me3-biotin labeled peptide (Anaspec cat #64357), 2 μM alpha-ketoglutaric acid in assay buffer of 50 mM HEPES, pH7.3, 0.005% Brij35, 0.5 mM TCEP, 0.2 mg/ml BSA, 50 μM sodium L-ascorbate, and 2 μM ammonium iron(II) sulfate. Reaction product was determined quantitatively by TR-FRET after the addition of detection reagent Phycolink Streptavidin-allophycocyanin (Prozyme) and Europium-anti-mono- or di-methylated histone H3 lysine 4 (H3K4me1-2) antibody (PerkinElmer) in the presence of 5 mM EDTA in LANCE detection buffer (PerkinElmer) at a final concentration of 25 nM and 1 nM, respectively.The assay reaction was initiated by the following: 2 μl of the mixture of 900 nM H3K4me3-biotin labeled peptide and 6 μM alpha-ketoglutaric acid with 2 μl of 11-point serial diluted inhibitor in 3% DMSO was added to each well of the plate, followed by the addition of 2 μl of 2.4 nM Jarid1B to initiate the reaction. The reaction mixture was incubated at room temp for 30 min, and terminated by the addition of 6 μl of 5 mM EDTA in LANCE detection buffer containing 50 nM Phycolink Streptavidin-allophycocyanin and 2 nM Europium-anti-H3K4me1-2 antibody. Plates were read by EnVisionMultilabel Reader in TR-FRET mode (excitation at 320 nm, emission at 615 nm and 665 nm) after 1 hr incubation at room temp. A ratio was calculated (665/615) for each well and fitted to determine inhibition constant (IC50).