Structure-based design of potent and selective inhibitors targeting RIPK3 for eliminating on-target toxicity in vitro
Haixia Su, Guofeng Chen, Hang Xie, Wanchen Li, Muya Xiong, Jian He, Hangchen Hu, Wenfeng Zhao, Qiang Shao, Minjun Li, Qiang Zhao, Yechun Xu
Abstract
The essential role of RIPK3 in necroptosis makes its inhibition a promising therapeutic strategy. However, the development of RIPK3 inhibitors has been hampered by on-target apoptosis and limited kinase selectivity. Inspired by the R69H mutation, which prevents on-target apoptosis by disrupting RIPK3 dimerization, we design LK-series inhibitors that effectively inhibit RIPK3 in biochemical assays and block TNF-α-induced necroptosis in both mouse L929 and human HT29 cells without inducing apoptosis. The representative compound, LK01003, shows high selectivity across a panel of 379 kinases. Our structural studies reveal that LK compounds act as Type I1/2 inhibitors, engaging a unique hydrophobic site and stabilizing an inactive conformation of RIPK3. Moreover, several type II inhibitors are also revealed to maintain RIPK3 in the inactive conformation and do not induce on-target apoptosis. These findings suggest a promising strategy for rational design of safe and selective inhibitors by locking the inactive conformation of RIPK3. Here the authors described the structure-based design of novel, selective RIPK3 inhibitors that do not induce on-target apoptosis by occupying a unique hydrophobic site and locking RIPK3 into an inactive conformation.