Characterizing the Interaction of Small-Molecule Kinase Inhibitors with Membranes to Understand their Specific Cellular Effects

蛋白激酶是生物学上最重要的蛋白质家族之一，它调节着蛋白质的功能，在几乎所有的生理过程中起着重要的调节作用。由于这种独特的重要性，蛋白质激酶的突变或失调是许多人类疾病的原因。因此，在过去的二十年中，这个酶家族的成员已经成为非常重要的药物靶点。治疗疾病的一个策略是开发和应用激酶抑制剂（小分子蛋白激酶抑制剂），主要应用于癌症治疗。对于大多数这些药物，已经报道了临床数据和构效关系，并提出了细胞机制来解释它们的抗肿瘤活性。然而，目前关于这些药物与膜的相互作用和影响的知识，特别是关于膜脂的作用是不够的。这是令人惊讶的，因为(i)（血浆）膜是相互作用的第一个目标，（ii）药物对靶激酶和/或靶外的影响可以被认为是由膜调节的。因此，该项目旨在表征选定的小分子激酶抑制剂与脂质膜的相互作用。药物的选择将基于不同的化学结构，这表明不同的膜相互作用模式。实验计划使用不同的生物物理方法提供脂质囊泡和细胞的定性和定量数据。在不同的脂质膜组成中，研究药物分子对膜的结构和动力学性质以及膜的位置和取向的影响。细胞实验将显示模型膜上的结果如何转化为生理系统。分子动力学模拟将在原子水平上提供药物影响的进一步见解。该实验将突出膜脂对小分子激酶抑制剂影响的作用。我们期望这些结果将(i)允许建立药物-膜相互作用的分子模型，（ii）为提出分子结构的修改以改善药物作用提供基础，以及（iii）有助于更好地了解这些分子的细胞效应，包括它们的功效，以及它们的副作用和与非靶标的相互作用。

Protein kinases are one of the biologically most important protein families which play a significant role in the regulation of nearly all physiological processes since they modulate the function of proteins. Due to this unique importance, mutation(s) or dysregulation(s) of protein kinases are a cause of many human diseases. Therefore, members of this family of enzymes have become very important drug targets over the past two decades. One strategy to treat diseases was to develop and apply kinase inhibitors (small molecule protein kinase inhibitors), which are mainly applied in cancer therapy. For most of these drugs, clinical data and structure-activity relationships have been reported and cellular mechanisms have been proposed to explain their antitumor activity. However, the current knowledge about the interaction and impact of these drugs with/on membranes especially with regard to the role of membrane lipids is insufficient. This is surprising since (i) (plasma) membranes are the first target of interaction and (ii) an impact of the drugs on the target kinase and/or off-targets can be assumed to be modulated by membranes. Therefore, the project aims to characterize the interaction of selected small-molecule kinase inhibitors with lipid membranes. Drugs will be selected on the basis of different chemical structures suggesting a different pattern of membrane interactions. Experiments are planned to provide qualitative and quantitative data on lipid vesicles and on cells using different biophysical approaches. The influence of the drug molecules on structural and dynamical membrane properties as well as their membrane position and orientation will be investigated in different lipid membrane compositions. Experiments on cells will show how the results on model membranes can be translated into the physiological system. Molecular dynamics simulations shall provide further insights of the drug impact on an atomistic level. The experiments will highlight the role of membrane lipids for the impact of small-molecule kinase inhibitors. We expect that the results will (i) allow to set up molecular models of drug-membrane interaction, (ii) give the basis for proposing modifications of the molecule structure in order to improve drug impact, and (iii) contribute to a better understanding of the cellular effects of these molecules with regard to their efficacy but also to their side effects and interactions with off-targets.