Afatinib (BIBW2992) Dimaleate

EGFR kinase: Each 100 µL enzyme reaction contained 10 μL of inhibitor in 50% Me2SO, 20 μL of substrate solution (200 mM HEPES pH 7.4, 50 mM Mg-acetate, 2.5 mg/mL poly (EY), 5 μg/mL bio-pEY) and 20 µL enzyme preparation. The enzymatic reaction is started by addition of 50 µL of a 100 µM ATP solution made in 10 mM MgCl2. Assays are carried out at room temperature for 30 min and terminated by the addition of 50 µL of stop solution (250 mM EDTA in 20 mM HEPES pH 7.4). 100 µL are transferred to a streptavidin coated microtiterplate, after an incubation time of 60 min at room temperature the plate is washed with 200 µL of wash solution (50 mM Tris, 0.05% Tween20). A 100 µL aliquot of a HRPO- labeled anti-PY antibody (PY20H Anti-Ptyr:HRP ) 250 ng/mL are added to the wells. After 60 min of incubation, the plate is washed three times with a 200 µL wash solution. The samples are then developed with a 100µL TMB Peroxidase Solution (A:B= 1:1). The reaction is stopped after 10 min. The plate is transferred to an ELISA reader and extinction is measured at OD450nm. HER2-IC enzyme: Enzyme activity is assayed in the presence or absence of serial inhibitor dilutions performed in 50 % Me2SO. Each 100 µL reaction contains similar components as described for EGFR kinase assay with addition of 1000 µM Na3VO4. The enzymatic reaction is started by addition of 50µL of 500 µM ATP solution made in 10 mM Mg-acetate. The dilution of the enzyme is set so that incorporation of phosphate into bio-pEY is linear with respect to time and amount of enzyme. The enzyme preparation is diluted in 20 mM HEPES pH 7.4, 130 mM NaCl, 0.05% Triton X-100, 1 mM DTT and 10% glycerol. Assays are carried out at room temperature for 30 min and terminated by the addition of 50 µL of stop solution. Src kinase assays: Each 100 µL reaction contained 10 µL of inhibitor in 50 % Me2SO, 20µL of enzyme preparation, 20 µL of substrate solution supplemented with 1000 µM Na3VO4. The enzymatic reaction is started by addition of 50 µL of a 1000 µM ATP solution made in 10 mM Mg-acetate. BIRK kinase assay: 250 mM Tris pH 7.4, 10mM DTT, 2.5 mg/mL poly(EY), 5 mg/mL bio-pEY is used as substrate solution and enzymatic reaction is started by addition of 50 µL of a 2 mM ATP solution made in 8 mM MnCl2, 20 mM Mg-acetate. VEGF2 and HGFR kinase assays: Assays are carried out at room temperature for 20 minutes and terminated by the addition of 10 µL of 5 % H3PO4. The precipitate is then trapped onto GF/B filters using a 96 well filter mate universal harvester. After extensive washing the filter plate is dried for 1 h at 50°C, sealed and incorporated radioactivity is determined by scintillation counting using a TopCount™ or a Microbeta b counter™.