NVS-PAK1-1 is a potent and selective allosteric PAK1 inhibitor with an IC50 of 5 nM.
NVS-PAK1-1 demonstrates high selectivity for inhibition of PAK1 over other PAK isoforms and the kinome in general. NVS-PAK1-1 has a biochemical PAK1 Kd of 7 nM and a PAK2 Kd of 400 nM. NVS-PAK1-1 shows excellent activity in biochemical assays and an exceptional selectivity profile against other known kinases. NVS-PAK1-1 at 6-20 μM inhibits the phosphorylation of the downstream substrate MEK1 Ser289. Consistent with the observation, NVS-PAK1-1 inhibits proliferation of Su86.86 cell line only above a concentration of 2 μM. In contrast, by applying a mixture of NVS-PAK1-1 and PAK2 shRNA, inhibition of downstream signaling and cell proliferation at a significantly lower 0.21 μM concentration are achieved[1].
NVS-PAK1-1 shows a relatively poor stability in rat liver microsomes (RLM) and this would limit its application for in vivo studies (t1/2 in RLM 3.5 min)[1].
[1]. Karpov AS, et al. Optimization of a Dibenzodiazepine Hit to a Potent and Selective Allosteric PAK1 Inhibitor. ACS Med Chem Lett. 2015 May 22;6(7):776-81.