New Molecular Probes For Protein Kinases

描述（由申请人提供）：蛋白激酶活性失调与许多疾病有关，包括癌症、糖尿病和慢性炎症。因此，蛋白激酶已成为现代药物发现中最重要的药物靶标之一。这些努力已经导致开发了大量的小分子抑制剂，其与蛋白激酶的ATP结合位点相互作用并且能够阻断其催化活性。有趣的是，许多这些药物利用蛋白激酶的ATP结合位点的构象灵活性，通过结合不同的活性位点构象。例如，药物Gleevec（伊马替尼）和Nexavar（索拉非尼）与其激酶靶点的ATP结合位点构象结合，这涉及称为DFG基序的催化重要结构元件的置换。虽然已经推测某些激酶抑制模式导致更理想的临床结果，但尚未在生化和/或细胞水平进行任何系统性比较。我们的假设是，ATP竞争性抑制剂，稳定不同的ATP结合位点构象的多结构域蛋白激酶将有不同的影响域和相互作用以外的活性位点。这导致了一种令人兴奋的可能性，即通过改变ATP结合位点占据的模式来抑制相同的激酶活性位点，从而获得不同的表型反应。为了验证这一假设，我们建议研究不同的抑制模式如何影响SRC家族激酶（SFK），这是一种充分表征的多结构域酪氨酸激酶。SFKs在多种信号转导过程中发挥着不同的作用，是重要的治疗靶点。此外，已经证明，除了它们的催化活性之外，SFK还具有许多依赖于它们的调节结构域的非催化支架功能。

DESCRIPTION (provided by applicant): Dysregulation of protein kinase activity has been implicated in a number of diseases, including cancer, diabetes and chronic inflammation. Therefore, protein kinases have emerged as one of the most important drug targets in modern drug discovery. These efforts have resulted in the development of a vast array of small molecule inhibitors that interact with the ATP-binding sites of protein kinases and are able to block their catalytic activities. Interestingly, many of these pharmacological agents exploit the conformational flexibility of the ATP-binding sites of protein kinases by binding to different actie site conformations. For example, the drugs Gleevec (imatinib) and Nexavar (sorafenib) bind to an ATP-binding site conformation of their kinase targets that involves displacement of a catalytically important structural element called the DFG motif. While it has been speculated that certain modes of kinase inhibition lead to more desirable clinical outcomes, there have not been any systematic comparisons at the biochemical and/or cellular level. Our hypothesis is that ATP-competitive inhibitors that stabilize different ATP-binding site conformations of multi-domain protein kinases will have divergent effects on domains and interactions outside of the active site. This leads to the exciting possibility that it may be possible to obtain different phenotypic responses through the inhibition of the same kinase active site by varying the mode of ATP-binding site occupancy. To test this hypothesis, we propose to study how different modes of inhibition affect the SRC family of kinases (SFKs), which are well-characterized, multi- domain tyrosine kinases. SFKs play diverse roles in multiple signaling processes and are important therapeutic targets. Furthermore, it has been demonstrated that beyond their catalytic activities, SFKs also have a number of non-catalytic scaffolding functions that are dependent on their regulatory domains.