CHEMBL5733308

In Vitro Raf Activity: Raf and biotinylated Mek, kinase dead, were combined at 2× final concentrations in assay buffer (50 mM Tris, pH 7.5, 15 mM MgCl2, 0.01% BSA and 1 mM DTT) and dispensed 5 ml per well in assay plates (Greiner white 384 well assay plates #781207) containing 0.25 ml of 40× of a Raf kinase inhibitor test compound diluted in 100% DMSO. The plate was incubated for 60 minutes at room temperature. The Raf kinase activity reaction was started by the addition of 5 mL per well of 2×ATP diluted in assay buffer. After 3 hours (b-Raf(V600E)) or 1 hour (c-Raf). The reactions were stopped and the phosphorylated product was measured using a rabbit anti-p-MEK (Cell Signaling, #9121) antibody and the Alpha Screen IgG (ProteinA) detection Kit (PerkinElmer #6760617R), by the addition of 10 mL to the well of a mixture of the antibody (1:2000 dilution) and detection beads (1:2000 dilution of both beads) in Stop/bead buffer (25 mM EDTA, 50 mM Tris, pH 7.5, 0.01% Tween20). The additions were carried out under dark conditions to protect the detection beads from light. A lid was placed on top of the plate and incubated for 1 hour at room temperature, then the luminescence was read on a PerkinElmer Envision instrument. The concentration of each compound for 50% inhibition (IC50) was calculated by non-linear regression using XL Fit data analysis software.