K-Ras (G12C) inhibitor 6 is an allosterical inhibitor of oncogenic mutation K-Ras G12C [1].
K-Ras (G12C) inhibitor 6 is a cysteine-reactive small molecule. It irreversibly binds to the G12C mutantion of GTPase K-Ras but not the wild-type K-Ras with the relative potency value of 4.2. The binding pocket of K-Ras for K-Ras (G12C) inhibitor 6 is a new allosteric pocket, S-IIP. Binding of this pocket results in a change of the relative nucleotide affinity of Ras to favour GDP over GTP, leading to an accumulation of inactive Ras. Since the mutation of K-Ras is quite common in human cancers, the inhibitor of K-Ras G12C should exert suppression activities in tumor cells. It has been reported that, some of the K-Ras G12C inhibitors are indeed effective to decrease cell viability and increase apoptosis in lung cancer cell lines [1].
References:
[1] Ostrem J M, Peters U, Sos M L, et al. K-Ras (G12C) inhibitors allosterically control GTP affinity and effector interactions. Nature, 2013, 503(7477): 548-551.