Biochem/physiol Actions | Chk2 Inhibitor II is a checkpoint kinase 2 inhibitor, which controls the p53 response to DNA breaks induced by radiation, leading to apoptosis. Protection of T-cells from apoptosis implies use as an adjuvant for radiation therapy in cancer. IC50= 15 nM; Ki= 37 nM. Chk2 Inhibitor II shows 1000-fold greater selectivity for the Chk2 serine/threonine kinase than for the Cdk1/B and CK1 kinases (for which IC50= 12 μM and 17 μM, respectively). Chk2 Inhibitor II weakly inhibits a panel of 31 other kinases (<25% inhibition at a concentration of 10 μM and prevents apoptosis of human CD4+ and CD8+ T-cells subjected to ionizing radiation (EC50= 3 μM and 7.6 μM, respectively). |