MPI-0479605 is an ATP competitive and selective inhibitor.

FLT3:0.08 μM, ERK2:3.9 μM, JNK1:0.11 μM, ALK:0.26 μM, FAK1:2.7 μM, Mps1:1.8 nM, B-Raf:3.2 μM, STK33:1.1 μM, FER:0.59 μM, Insulin receptor:0.38 μM, PLK4:3.3 μM

In Vitro Kinase Assays and Selectivity Screening : To measure Mps1 activity, 25 ng of recombinant, full-length enzyme is incubated in reaction buffer (50 mM Tris-HCl pH 7.5, 10 mM MgCl2, 0.01% Triton X-100 and 5 μM Myelin basic protein (MBP)) containing vehicle (DMSO alone) or inhibitors. Forty μM ATP (2xKm) is added with 1 μCi [γ-33P]ATP and the reaction is incubated at room temperature for 45 minutes. Reactions are terminated with 3% phosphoric acid and transferred to P81 filter plates. Samples are washed in 1% phosphoric acid and 33P radioactivity is measured on a TopCount scintillation reader. In-house kinase assays are all carried out at 2xKm ATP concentrations. MPI-0479605 (500 nM) is also screened against a larger kinase panel.

Cells are treated for 3 or 7 days with various concentrations of MPI-0479605 and the GI50 is determined. Cell viability is measured with CellTiter-Glo. (Only for Reference)