Kinome-Wide Spectroscopic Study of Drug Binding Site Electrostatics

描述(申请人提供)：蛋白激酶在调节细胞生长和增殖的信号通路中发挥核心作用，而异常的激酶活性有助于许多癌症的发展。最近在靶向蛋白激酶抑制剂治疗特定癌症方面的成功，特别是肺癌和慢性髓系白血病，强调了这些蛋白质在肿瘤发生中的重要性，并强调了需要更多的激酶抑制剂来治疗其他癌症。新的激酶抑制剂的开发是具有挑战性的，因为这些小分子靶向的主要部位--激酶ATP结合位点的高度序列保守性，使得获得对特定的激酶具有选择性的化合物变得困难。目前的研究旨在通过一种全新的实验方法来解决这个问题，这种方法利用了物理化学的进步。在目标1中，一种名为振动斯塔克光谱的新光谱技术将被用于构建ATP结合位点的静电学图谱，以及它如何在该蛋白质家族的约500个成员中变化。这些测量将使用具有电场振动探针的激酶抑制剂进行，其中探针报告它们在结合到ATP结合部位时所经历的静电。由于这些静电图谱与从抑制剂的角度来看ATP结合部位的物理环境有关，因此它们将直接了解抑制剂的化学结构的变化将如何影响与激酶的相互作用。在这些测量中发现的激酶之间的差异可以被用来设计更具选择性的药物。在目标2中，这种可能性将通过进行大规模结合分析来量化，在大规模结合分析中，将揭示一组激酶抑制剂的选择性，并直接与静电测量进行比较，以揭示静电变化如何决定选择性。虽然选择性分析很常见 在制药工业中，通过与目标1中确定的静电图进行比较，将首次确定缓蚀剂选择性的物理基础，为开发具有新的选择性图谱的缓蚀剂指明了方向。在目标3中，将通过研究蛋白质基团和结合水分子的动态重排如何影响这种环境来完成对ATP结合位点的表征。蛋白激酶现在构成了一组主要的药理靶点，这项工作将构成第一次全面的实验研究，研究这些蛋白质的物理性质如何决定它们与药物分子的相互作用。 公共卫生相关性：癌症是发达国家的主要死亡原因之一，对大多数患者来说，除了放射治疗和手术外，治疗主要围绕非选择性细胞毒药物的使用。最近，在用激酶抑制剂治疗几种类型的癌症方面取得了巨大的成功，这证明了一种不同的方法，即选择性地针对导致这种疾病的分子异常，具有许多优点。该项目将研究控制药物选择性靶向特定蛋白激酶的能力的物理原理，可能会导致由突变的蛋白激酶引起的癌症的新疗法。

DESCRIPTION (provided by applicant): Protein kinases play central roles in the signaling pathways that regulate the growth and proliferation of cells, and aberrant kinase activity contributes to the development of many cancers. Recent success in treating particular cancers with targeted protein kinases inhibitors, notably lung cancer and chronic myeloid leukemia, underscores the importance of these proteins in oncogenesis, and highlights the need for additional kinase inhibitors to treat other cancers. The development of new kinase inhibitors is challenging because the high sequence conservation of the kinase ATP-binding site, the major site targeted by these small molecules, makes it difficult to obtain compounds that are selective for particular kinases. The current study aims to address this problem through an entirely new experimental approach that utilizes advances in physical chemistry. In Aim 1, a new spectroscopic technique called vibrational Stark spectroscopy will be used to construct a map of the electrostatics of the ATP-binding site and how it varies across the ~500 members of this protein family. These measurements will be made using kinase inhibitors that possess vibrational probes of electric field, in which the probes report on the electrostatics they experience when bound in the ATP- binding site. Because these electrostatic maps relate to how the physical environment in the ATP- binding site appears from the perspective of the inhibitors, they will yield direct insight into how changes to the chemical structure of the inhibitors would affect the interaction with kinases. Differences uncovered between kinases in these measurements could be exploited to design more selective drugs. In Aim 2, this possibility will be quantified by performing large-scale binding assays in which the selectivity of panels of kinase inhibitors will be revealed and directly compared to the electrostatics measurements to reveal how electrostatic variation dictates selectivity. While selectivity profiling is commonplace in the pharmaceutical industry, the comparison with the electrostatic maps determined in Aim 1 will allow the physical basis of inhibitor selectivity to be determined for the first time, guidingthe way to the development of inhibitors with new selectivity profiles. In Aim 3 the characterization of the ATP-binding site will be completed by studying how this environment is affected by the dynamic rearrangements of protein groups and bound water molecules. The protein kinases now constitute a major group of pharmacological targets, and taken together this work will constitute the first comprehensive experimental study of how the physical properties of these proteins dictate their interaction with drug molecules. PUBLIC HEALTH RELEVANCE: Cancer is one of the primary causes of death in the developed world, and for most patients treatment revolves mainly around the use of non-selective cytotoxic drugs, in addition to radiation therapy and surgery. Recent dramatic success in the treatment of several types of cancer with kinase inhibitors has demonstrated that a different approach, which selectively targets the molecular anomaly responsible for the disease, has many advantages. This project will study the physical principles that govern the ability of drugs to selectivity target particular protein kinases, potentially leading to new treatments for cancers caused by mutated protein kinases.