Conformational Dynamics of Protein Tyrosine Kinases Src and Abl

蛋白激酶介导许多细胞信号传导事件，并且它们的严格控制对于调节细胞的重要功能是必不可少的。 从细胞分裂到能量代谢。因此，蛋白质激酶被用于治疗癌症并不奇怪。 它直接或间接参与许多疾病，激酶是关键的药物靶点。例如，Src 激酶是第一个被鉴定的原癌基因，并且形成了去调节的Abl融合蛋白 BCRAbI是95%慢性髓性白血病患者的病因。x射线晶体结构 已经表明，相同的激酶可以获得活性和各种非活性构象，这意味着， 激酶具有固有的柔性。活跃和不活跃状态是如何稳定的，以及这些状态是如何 相互转换是理解激酶调节关键问题。因为X射线晶体结构提供了 只有静态快照，我们将使用核磁共振（NMR）实验和配体结合 动力学来研究Abl和Src激酶结构域中结构相互转化的时间尺度和幅度。 BCR-AbI是临床上非常成功的药物伊马替尼（格列卫，诺华公司）在治疗 慢性粒细胞白血病（CML）。伊马替尼的临床成功是由于其出色的特异性， 仅与激酶的非活性构象结合。因此，药物结合密切相关的 活动状态和非活动状态之间的相互转换。这项研究的目的是检查时间尺度和 活性和非活性构象之间的这些相互转换的途径，结构的动力学如何 这些元素与激酶的催化转换以及耐药性突变如何影响这些动力学有关。 因此，我们将比较Src和Abl之间主链运动的时间尺度和幅度 通过NMR实验测定药物存在下的激酶。配体结合动力学将用于解决 调节结构域对激酶动力学的作用以及不同类型的 激酶抑制剂。蛋白质可塑性和动力学对抑制剂混杂的作用将通过 激酶 * 抑制剂复合物的结构研究、抑制剂结合动力学和生物化学测定。

Protein kinases mediate many cell signaling events, and their tight control is essential for regulating vital processes ranging from cell division to energy metabolism. Thus, it is not surprising that protein kinases are directly or indirectly involved in many diseases and that kinases are key drug targets. For example, Src kinase was the first identified proto-oncogene and the formation of a de-regulated Abl fusion protein (BCRAbI) is the cause of disease in 95% of patients with chronic myeloid leukemia. X-ray crystal structures have shown that the same kinases can attain an active and various inactive conformations, implying that kinases are inherently flexible. How the active and inactive states are stabilized and how these states interconvert are key questions in understanding kinase regulation. Because X-ray crystal structures provide only static snapshots, we will use nuclear magnetic resonance (NMR) experiments and ligand binding kinetics to study the timescales and amplitudes of structural interconversions in Abl and Src kinase domains. BCR-AbI is the target of the clinically highly successful drug imatinib (Gleevec¿, Novartis) in the treatment of chronic myelogenous leukemia (CML). The clinical success of imatinib is due to its excellent specificity, binding only to the inactive conformation of the kinase. Therefore drug binding is intimately related to the interconversion between active and inactive states. The goal of this study is to examine timescales and pathways ofthese interconversions between active and inactive conformations, how dynamics of structural elements relate to catalytic turnover of the kinase and how drug resistance mutations affect these dynamics. Therefore, we will compare the timescales and amplitudes of backbone motions between Src and Abl kinases in the presence of drugs by NMR experiments. Ligand binding kinetics will be used to address the role of the regulatory domains on kinase dynamics and the binding mechanisms of different classes of kinase inhibitors. The role of protein plasticity and dynamics on inhibitor promiscuity will be addressed by structural studies on kinase*inhibitor complexes, inhibitor binding kinetics and biochemical assays.