Chemical Inhibitors of the Proteasomal ATPases

蛋白酶体抑制剂现在是多发性骨髓瘤的首选治疗方案之一 并且正在针对多种其他癌症进行临床试验评估。然而，在这方面， 这些化合物靶向蛋白酶体的三个活性位点之一， 缺点包括副作用和新出现的耐药性。因此， 开发和评估新型蛋白酶体抑制剂。 最近，我们报道了第一个药理学的发现和表征， 26 S蛋白酶体的ATP酶之一的抑制剂。这六个不同的AAA级 ATP酶（称为Rpts 1-6）位于19 S调节颗粒（RP）的碱基， 蛋白酶体的桶状20 S核心颗粒（CP）的每一端。ATP酶 构成蛋白质解旋活性，其作用是将底物引入到催化剂中， 内部的20 S CP，也持有开放的皮瓣在入口处，否则阻碍 衬底存取。然而，关于每种蛋白质对蛋白质的贡献知之甚少。 ATP依赖的解折叠过程。最近对酵母的研究，许多来自我们自己的 实验室研究也表明，这些蛋白质在 RNA聚合酶II转录、DNA修复和可能的DNA复制。的 六个ATP酶中的每一个对所有这些活动的单独贡献尚不清楚。 在这项提案中，我们打算识别和优化六种蛋白质中每一种的类肽抑制剂。 蛋白酶体ATP酶。将合成并筛选大型类肽文库， 使用为上述抑制剂开发的程序和测定法鉴定命中物， 针对Rpt 4。将制定快速优化程序，以提高命中率 到nM引线。然后将这些化合物用于确定蛋白酶体是否 ATP酶在哺乳动物转录中起关键作用，如在酵母中的情况。 这些蛋白质的有效抑制剂的分离将为未来奠定基础。 生物化学实验，以剖析每种蛋白质在不同步骤中的作用， 转录和蛋白水解。未来的实验还将包括测试它们的活性 在各种小鼠癌症模型中。

Proteasome inhibitors are now one of the first treatment options for multiple myeloma and are being evaluated in clinical trials against a variety of other cancers. However, these compounds, which target one of the three active sites of the proteasome, have drawbacks including side effects and emerging resistance. Therefore, it is important to develop and evaluate novel classes of proteasome inhibitors. Recently, we reported the discovery and characterization of the first pharmacological inhibitor of one of the ATPases of the 26S proteasome. These six different AAA class ATPases (called Rpts 1-6) are located at the base 19S regulatory particle (RP) that caps each end of the barrel-like 20S core particle (CP) of the proteasome. The ATPases constitute a protein unwinding activity that acts to introduce substrates into the catalytic interior of the 20S CP and also holds open a flap at the entrance that otherwise impedes substrate access. However, little is known about the contribution of each protein to the ATP-dependent unfolding process. Recent studies in yeast, many from our own laboratory, have also shown that these proteins play important, non-proteolytic roles in RNA polymerase II transcription, DNA repair and perhaps DNA replication. The individual contributions of each of the six ATPases to all of these activities are unclear. In this proposal, we intend to identify and optimize peptoid inhibitors of each of the six proteasomal ATPases. Large peptoid libraries will be synthesized and screened to identify hits using procedures and assays developed for the inhibitor mentioned above, which targets Rpt4. Rapid optimization procedures will be developed to improve the hits into nM leads. These compounds will then be utilized to determine if the proteasomal ATPases play a critical role in mammalian transcription, as is the case in yeast. The isolation of potent inhibitors of these proteins will then set the stage for future biochemical experiments to dissect the role of each protein in various steps in transcription and proteolysis. Future experiments would also include testing their activity in various mouse models of cancer.