SGC-GAK-1 (1) is a potent, selective, cell-active chemical probe for cyclin G-associated kinase (GAK). However, 1 was rapidly metabolized in mouse liver microsomes by cytochrome P450-mediated oxidation, displaying rapid clearance in liver microsomes and in mice, which limited its utility in in vivo studies. Chemical modifications of 1 that improved metabolic stability, generally resulted in decreased GAK potency. The best analog in terms of GAK activity in cells was 6-bromo-N-(1H-indazol-6-yl)quinolin-4-amine (35) (IC50 = 1.4 μM), showing improved stability in liver microsomes while still maintaining a narrow spectrum activity across the kinome. As an alternative to scaffold modifications we also explored the use of the broad-spectrum cytochrome P450 inhibitor 1-aminobenzotriazole (ABT) to decrease intrinsic clearance of aminoquinoline GAK inhibitors. Taken together, these approaches point towards the development of an in vivo chemical probe for the dark kinase GAK.
SGC-GAK-1 (1)是一种针对cyclin G相关激酶(GAK)的有效、选择性、细胞活性化学探针。然而,在小鼠肝微粒体中,1通过细胞色素P450介导的氧化迅速代谢,导致在肝微粒体和小鼠中迅速清除,从而限制了其在体内研究中的实用性。对1的化学修饰改善了代谢稳定性,但通常导致GAK效力降低。在细胞中GAK活性方面效果最好的类似物是6-溴-N-(1H-吲唑-6-基)喹啉-4-胺(35)(IC50 = 1.4 μM),在肝微粒体中显示出改善的稳定性,同时仍保持着在激酶组中的狭谱活性。作为对骨架修饰的替代方案,我们还探索了广谱细胞色素P450抑制剂1-氨基苯并三唑(ABT)的使用,以降低氨基喹啉GAK抑制剂的内在清除率。综合考虑这些方法,指向了开发一种针对暗激酶GAK的体内化学探针的方向。