Investigation of Molecular Dynamics of Substrate Transmembrane alpha-Helices by Solution and Solid-State NMR Spectroscopy

通过溶液和固态核磁共振波谱研究底物跨膜 α 螺旋的分子动力学

• 批准号: 280771871
• 负责人: Professor Dr. Daniel Huster, Ph.D.
• 金额: --
• 依托单位: Institut für Medizinische Physik und Biophysik
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/280771871?language=en
• 关键词: Investigation; Molecular; Dynamics; Substrate; Transmembrane

Intramembrane proteolysis is an important mechanism of membrane protein processing with immediate relevance for the development of diseases. How this process takes place in the lipophilic environment and which details of the sequence or dynamic features of the substrates are essential for proteolysis are questions that are currently under debate. In this project we investigate the structural and dynamical requirements of selected substrate TM helices by liquid and solid-state NMR spectroscopy, currently the only experimental techniques to study dynamics of biomolecules at atomic detail. We will begin with two model TM helices: APP, a well-studied gamma-secretase substrate, and PINK1, substrate of the rhomboid protease PARL. In Goal 1 we will concentrate on the conformational plasticity of the TM domains in solution and membrane-mimicking environments focusing in particular on deviations from the canonical helical structure and searching for lowly populated states (hidden states) in exchange with the main conformation as well as the related dynamical parameters. We will directly measure dynamical parameters characterizing the TM domains such as local exchange rates and motional amplitudes for individual interatomic vectors in a range of membrane models. In Goal 2 we will investigate the impact of mutations of the two TM domains. Some of these mutations are already known to impair proteolysis. We will clarify how they alter TM helix flexibility. In Goal 3 we will study how the membrane influences TM helix structural and dynamic properties. The expected results will be compared with molecular dynamics simulations conducted in P7 and show if the TM domain dynamics is a relevant factor for the protease recognition and/or processing. Depending on progress in goals 1-3, protocols and experiments will be applied on selected novel substrates identified in P1/P2/P3 to judge the general validity of these studies.

膜内蛋白水解是膜蛋白加工的重要机制，与疾病的发展有关。该过程如何发生在亲脂环境中，以及底物的序列或动态特征的哪些细节对于蛋白水解至关重要，这是当前正在争论的问题。在该项目中，我们通过液体和固态NMR光谱研究了选定的底物TM螺旋的结构和动力学要求，目前，唯一在原子细节研究生物分子动力学的实验技术。我们将从两个型号TM螺旋开始：APP，一个经过良好研究的伽马 - 分泌酶底物和Rhomboid蛋白酶PAR的底物的PINK1。在目标1中，我们将集中于溶液和模拟膜的TM结构域的构象可塑性，尤其是针对与规范螺旋结构的偏差，并寻找与主要构型相互交换的人口较低的状态（隐藏状态）以及相关的动态参数。我们将直接测量表征TM域的动态参数，例如局部汇率和各个膜模型中各个原子间矢量的运动振幅。在目标2中，我们将研究两个TM域突变的影响。这些突变中的一些已经众所周知会损害蛋白水解。我们将阐明它们如何改变TM螺旋灵活性。在目标3中，我们将研究膜如何影响TM螺旋结构和动态特性。预期结果将与P7中进行的分子动力学模拟进行比较，并显示TM域动力学是否是蛋白酶识别和/或处理的相关因素。根据目标1-3的进展，方案和实验将应用于在P1/P2/P3中确定的选定的新型底物上，以判断这些研究的一般有效性。