KPT276 (KPT 276) is an orally bioavailable selective inhibitor of nuclear export (SINE) that irreversibly bind to CRM1 and block the function of CRM1.

Kinase inhibition assay: A glutathione S-transferase-tagged kinase domain construct of the intracellular portion of the PDGFR-β (amino acids 693-1401, accession no. J03278) is expressed in Sf-9 cells (baculovirus expression system). Enzyme kinetics are determined by incubating the enzyme with increasing concentrations of ATP in phosphorylation buffer [50 mmol/L HEPES (pH 7.3), 125 mmol/L NaCl, 24 mmol/L MgCl2 in Nunc Immuno MaxiSorp 96-well plates previously coated with 100 μL of 100 μg/mL poly-Glu-Tyr (4:1 ratio) diluted in PBS. After 10 minutes, the plates are washed (PBS, 0.1% Tween 20), incubated with anti-phosphotyrosine-horseradish peroxidase antibody, and diluted in PBS, 0.05% Tween 20, 3% BSA for 30 minutes at room temperature. The plates are washed as above and incubated with 3,3',5,5'-tetramethylbenzidine. The reaction is stopped by adding an equal volume of 0.09 NaH2SO4. The phosphotyrosine-dependent signal is then quantitated on a plate reader at 450 nm. For routine enzyme assays, the enzyme is incubated with 10 μM ( final) ATP in the presence of compound diluted in DMSO (1.6% v/v DMSO assay final) for 30 minutes at room temperature in plates, as above, previously coated with 100 μL of 6.25 μg/mL poly-Glu-Tyr. The remainder of the assay is carried out as above, and IC50 values are calculated as percent inhibition of control.

H2O: < 1 mg/mL (insoluble or slightly soluble)

DMSO: 11 mg/mL (25.81 mM), Sonication is recommended.

Ethanol: < 1 mg/mL (insoluble or slightly soluble)

10% DMSO+40% PEG300+5% Tween 80+45% Saline: 2 mg/mL (4.69 mM), Sonication is recommended.