CHEMBL5733644

Measurement of EGFR Inhibitory Activity: With regard to the setting of the conditions for a method for measuring the inhibitory activity of a compound against EGFR kinase activity in vitro, it is described in the consumable reagent supplies price list for LabChip (registered trademark) series of PerkinElmer, Inc. that FL-PEPTIDE 22 corresponds to a substrate peptide for the measurement of EGFR kinase activity. Therefore, a biotinated peptide (biotin-EEPLYWSFPAKKK) was produced by referring to the amino acid sequence of the peptide. The purified recombinant human EGFR protein used in the test was purchased from Carna Biosciences, Inc.With regard to the measurement of the inhibitory activity of the compounds, firstly, monofumarate of Compound A was diluted stepwise with dimethyl sulfoxide (DMSO). Subsequently, EGFR protein, a substrate peptide (final concentration was 250 nM), magnesium chloride (final concentration was 10 mM), manganese chloride (final concentration was 10 mM), ATP (final concentration was 1.5 μM), and a DMSO solution of the test compounds (final concentration of DMSO was 2.5%) were added to a buffer solution for kinase reaction (20 mM HEPES (pH 7.5), 2 mM dithiotheitol, 0.01% Triton X-100), and after the solution was incubated for 120 minutes at 25° C., a kinase reaction was carried out. The reaction was terminated by adding EDTA thereto so as to obtain a final concentration of 24 mM. Subsequently, a detection liquid containing Eu-labeled anti-phosphotyrosine antibody PT66 (PerkinElmer, Inc.) and SURELIGHT APC-SA (PerkinElmer, Inc.) was added thereto, and the system was left to stand for 2 hours or longer at room temperature. Finally, the amount of fluorescence upon irradiation with excitation light having a wavelength of 337 nm was measured at two wavelengths of 620 nm and 665 nm, with a PHERAstar FS (BMG Labtech GmbH). The amount of phosphorylation reaction was determined from the ratio of the amounts of fluorescence at the two wavelengths, and the compound concentration at which the phosphorylation reaction could be suppressed by 50% was defined as the IC50 value (nM).