Compared to most ATP-site kinase inhibitors, small molecules that target an allosteric pocket have the potential for improved selectivity due to the often observed lower structural similarity at these distal sites. Despite their promise, relatively few examples of structurally confirmed, high-affinity allosteric kinase inhibitors exist. Cyclin-dependent kinase 2 (CDK2) is a target for many therapeutic indications, including non-hormonal contraception. However, an inhibitor against this kinase with exquisite selectivity has not reached the market because of the structural similarity between CDKs. In this paper, we describe the development and mechanism of action of type III inhibitors that bind CDK2 with nanomolar affinity. Notably, these anthranilic acid inhibitors exhibit a strong negative cooperative relationship with cyclin binding, which remains an underexplored mechanism for CDK2 inhibition. Furthermore, the binding profile of these compounds in both biophysical and cellular assays demonstrate the promise of this series for further development into a therapeutic selective for CDK2 over highly similar kinases like CDK1. The potential of these inhibitors as contraceptive agents is seen by incubation with spermatocyte chromosome spreads from mouse testicular explants, where they recapitulate Cdk2^-/- and Spdya^-/- phenotypes.

与大多数 ATP 位点激酶抑制剂相比，针对变构袋的小分子具有提高选择性的潜力，因为这些远端位点经常观察到较低的结构相似性。尽管有希望，但结构证实的高亲和力变构激酶抑制剂的例子相对较少。细胞周期蛋白依赖性激酶 2 (CDK2) 是许多治疗适应症的靶标，包括非激素避孕。然而，由于CDK之间的结构相似性，具有精细选择性的针对该激酶的抑制剂尚未进入市场。在本文中，我们描述了以纳摩尔亲和力结合 CDK2 的 III 型抑制剂的开发和作用机制。值得注意的是，这些邻氨基苯甲酸抑制剂与细胞周期蛋白结合表现出强烈的负协同关系，这仍然是 CDK2 抑制机制尚未得到充分探索。此外，这些化合物在生物物理和细胞测定中的结合特征表明，该系列有望进一步开发为针对 CDK2 的选择性治疗药物，而不是高度相似的激酶（如 CDK1）。通过与小鼠睾丸外植体的精母细胞染色体扩散一起孵育，可以看出这些抑制剂作为避孕药的潜力，它们重现了Cdk2 ^-/-和Spdya ^-/-表型。