Development of Allosteric Modulators of Phosphatidylinositol 3-Kinase

项目摘要 大多数激酶抑制剂靶向ATP结合位点，并且经常抑制人类中的许多激酶。 kinome。由于泛激酶抑制剂的性质，在临床前治疗中经常观察到严重的副作用。 和临床研究。因此，需要更特异性的治疗剂以实现安全有效的治疗 人类疾病。变构调节剂（激动剂和拮抗剂）具有比ATP更大的潜力。 竞争性抑制剂以实现选择性，这是由于保守性小得多的变构结合位点。高和 变构调节剂也可以获得一致的效力。此外，变构调节剂可 在细胞和体内显示出与ATP竞争性 抑制剂的这些试剂可用于研究激酶的特定生物学和病理学功能 在人类疾病中。然而，识别变构先导化合物及其结合口袋是一个很好的方法。 这一挑战阻碍了激酶变构调节剂的发展。所以，在这个奖项中， 提出了几种开发磷脂酰肌醇3-激酶变构调节剂的方法 (PI3Kα），它与人类癌症、新陈代谢、先天和适应性免疫以及自闭症谱系有关 disorder.在激酶结构域和Ras结合之间的界面处捕获的肽片段 使用PI 3 K α的结构域作为变构起始化合物以产生PI 3 K α的变构调节剂。 我们的早期中试研究支持了我们的假设，并产生了合适的起始剂， PI 3 K α变构激动剂和拮抗剂的开发。因此，我们将开发高效的变构 通过应用结构导向药物设计技术，如接头搜索，支架， 跳频和虚拟合成与筛选（目标1）。固相肽合成和液相 利用有机合成技术，制备了一个模拟肽库和一系列小分子化合物， 类似物，分别。将研究PI 3 K α与别构调节剂复合物的X射线共晶结构。 确定并用于基于结构的设计。一旦低纳摩尔抑制和激活被激活， 在生物化学测定中实现的，变构调节剂的细胞效力将在一系列细胞- 基于增殖和功能测定（Aim 2）。此外，由PI 3 K α介导的细胞信号传导途径 将与高效变构调节剂结合ATP竞争性抑制剂进行研究。 总之，拟议的研究将对生物医学研究和药物发现产生重大影响， 激酶中新型化学实体的发现和发现变构调节剂的新概念。的 本项目开发的变构调节剂将有助于研究新的激酶介导的功能， 以确定其在人类疾病中的特定作用和需求。最后，概念和 该项目建立的技术将为发现变构调节剂提供坚实的战略， 激酶和大量的新的化学实体在激酶药物发现。

Project Summary Most kinase inhibitors target the ATP binding site, and frequently inhibit numerous kinases in the human kinome. Due to the nature of pan-kinase inhibitors, severe side effects are frequently observed in pre-clinical and clinical studies. Therefore, more specific therapeutics are desirable to achieve safe and effective treatment of human diseases. Allosteric modulators (agonists and antagonists) have greater potential than ATP- competitive inhibitors to achieve selectivity due to the much less conserved allosteric binding sites. High and consistent potency can also be achieved by the allosteric modulators. Furthermore, allosteric modulators can show different efficacies and pharmacological effects in cell and in vivo, compared to ATP competitive inhibitors. These agents can be applied to investigate specific biological and pathological functions of kinases in human diseases. However, identifying allosteric lead compounds and their binding pockets is a great challenge that retards the development of allosteric modulators of kinases. So, in this Award a novel concept and several approaches are proposed to develop allosteric modulators of Phosphatidylinositol 3-Kinase (PI3Kα), which is involved in human cancer, metabolism, innate and adaptive immunity, and Autism spectrum disorder. The peptide fragment trapped at the interface between the kinase domain and the Ras binding domain of PI3Kα was employed as an allosteric starting compound to generate allosteric modulators of PI3Kα. Our early stage pilot studies supported our hypothesis and produced proper starting agents for the development of allosteric agonists and antagonists of PI3Kα. Therefore, we will develop highly potent allosteric modulators of PI3Kα by applying structure-guided drug design techniques such as linker search, scaffold hopping, and virtual synthesis and screening (Aim 1). Solid phase peptide synthesis and solution phase organic synthesis will be applied for generating a peptidomimetic library and a series of small molecule analogs, respectively. X-ray co-crystal structures of PI3Kα in complex with allosteric modulators will be determined and used for the structure-based design. Once low nanomolar inhibition and activation are achieved in biochemical assays, cellular potency of allosteric modulators will be assessed in a series of cell- based proliferation and functional assays (Aim 2). Furthermore, cellular signaling pathways mediated by PI3Kα will be investigated with highly potent allosteric modulators in combination with ATP-competitive inhibitors. In summary, the proposed research will have high impact on biomedical research and drug discovery in terms of new types of chemical entities in kinases and a new concept for the discovery of allosteric modulators. The allosteric modulators developed in this project will facilitate the investigation of new kinase functions mediated by PI3Kα to determine its specific roles and requirement in human diseases. Finally, the concepts and techniques established in this project will provide solid strategies for discovery of allosteric modulators of kinases and a large pool of new chemical entities in kinase drug discovery.