Biochemical Kinase Assay: Liquid handling and incubation steps were done on an Innovadyne Nanodrop Express equipped with a robotic arm (Thermo CatX, Caliper Twister II) and an incubator (Liconic STX40, Thermo Cytomat 2C450). The assay plates were prepared by addition of 50 nl per well of compound solution in 90% DMSO. The kinase reactions were started by stepwise addition of 4.5 ul per well of peptide/ATP-solution (50 mM HEPES, pH 7.5, 1 mM DTT, 0.02% Tween20, 0.02% BSA, 0.6% DMSO, 10 mM beta-glycerophosphate, and 10 uM sodium orthovanadate, 16 mM MgCl2, 1122 uM ATP, 4 uM peptide (5-Fluo-Ahx-KKKKEEIYFFFG-NH2, Biosyntan GmbH) and 4.5 ul per well of enzyme solution (50 mM HEPES, pH 7.5, 1 mM DTT, 0.02% Tween20, 0.02% BSA, 0.6% DMSO, 10 mM beta-glycerophosphate, and 10 uM sodium orthovanadate, 16 mM MgCl2, 6 nM FGFR4 (GST-FGFR4(388-802), produced in-house by expression in insect cells and affinity chromatography). Kinase reactions were incubated at 30° C. for 60 minutes and subsequently terminated by addition of 16 ul per well of stop solution (100 mM HEPES pH 7.5, 5% DMSO, 0.1% Caliper coating reagent, 10 mM EDTA, and 0.015% Brij35).
Inhibition of FGFR4 (388 to 802 residues) (unknown origin) using 5-Fluo-Ahx-KKKKEEIYFFFG-NH2 as substrate after 60 mins by microfluidic mobility shift assay
Inhibition of TEL-fused FGFR4 cytoplasmic/juxta membrane domain (unknown origin) expressed in mouse Ba/F3 cells assessed as reduction in FGFR4 autophosphorylation after 1 hr by ELISA
Drug metabolism in human liver microsome assessed as reduction of aldehyde group at 10 mM measured after 15 mins in presence of NADPH by LC-MS analysis
Selectivity ratio of IC50 for inhibition of FGFR4 in mouse BAF3 cells assessed as decrease in FGFR4 phosphorylation to IC50 for inhibition of wild-type recombinant FGFR4 kinase domain (443 to 753) (unknown origin) expressed in Sf9 insect cells
Inhibition of recombinant non-phosphorylated FGFR4 kinase domain (442 to 753) (unknown origin) expressed in Sf9 insect cells using 5-Fluo-Ahx-KKKKEEIYFFFG-NH2 peptide as substrate in presence of ATP measured after 60 mins by caliper microfluidic mobility shift assay