Structure-Dynamics Relationships in Proteins: A multi-faceted characterizati

描述（由申请人提供）：蛋白质中的结构-动力学关系：通过NMR弛豫测量和分子动力学模拟对结构及其波动进行多方面表征。蛋白质波动及其与蛋白质结构和功能的关系继续挑战生物物理测量和模拟。蛋白质的所有三个方面（动力学，结构和功能）都是紧密联系的。最近已经清楚的是，蛋白质动力学的改变可以单独用于蛋白质中遥远位点之间的通信。这种沟通管道（以及它们之间的耦合）所涉及的结构和波动尚未得到很好的理解。我们解决几个方面的结构-动力学关系。目标1：在一个联合NMR实验-计算精化的方法，我们试图提高蛋白质结构系综的ps-ns时标动力学的代表性。一个统计和信息理论为基础的方法将被用来评估实验的限制和数量的局部构象在结构优化。结果将进行比较，无约束的分子动力学模拟和NMR弛豫测量的顺序参数。结构系综将有助于药物设计中的配体和蛋白质对接计算。目的2：我们的研究旨在揭示允许蛋白质环和核心结构波动之间耦合的设计原则。同样，两个解决方案NMR实验和计算策略将结合几种蛋白质，包括泛素和RhoGT结合域丛蛋白-B1（RBD），它有一个泛素折叠与长环插入。将操纵环以及蛋白质核心，以探测两者之间可能的动态耦合。还将检查RBD-GTdR复合物在蛋白质-蛋白质界面上可能的运动偶联。目标3：蛋白质的全局随机运动可能会影响本地的，内部的动力学的可能性，将使用NMR弛豫在不同的溶剂粘度和长时间尺度的朗之万/布朗动力学模拟检查。目标4：将测试用于构象空间的增强采样的方法，并将根据NMR数据验证用于分子动力学程序CHARMM/NAMD的下一代力场。总的来说，在这个项目中，几个计算和实验策略将被汇集在一起，以提供深入了解蛋白质结构之间的关系，以及内部和全球蛋白质动力学。研究的几种蛋白质在肿瘤发生和细胞转移中具有重要作用，它们的进一步研究将为设计诊断或治疗药物以对抗癌症提供新的途径。 公共卫生相关性：联合实验和计算项目将提供详细的洞察蛋白质结构和蛋白质内部和全球动态之间的相互关系。解决的基本问题是蛋白质生物物理学和结构生物学领域的基础。这项研究的结果将有助于了解蛋白质的功能，特别是细胞信号蛋白。其中几种蛋白质在癌症的发展和扩散中起着重要作用，对它们的进一步研究将为诊断或治疗药物的设计提供新的途径。

DESCRIPTION (provided by applicant): Structure - Dynamics Relationships in Proteins: Multi-faceted characterization of structure and its fluctuations by NMR relaxation measurements and molecular dynamics simulations. Protein fluctuations and their relationship to protein structure and function continue to challenge biophysical measurements and simulations. All three aspects of proteins (dynamics, structure and function) are intimately linked. Recently it has become clear that alterations in protein dynamics alone can be used to communicate between distant sites in proteins. The structures and fluctuations that are involved in such communication conduits (and the coupling between them) are not yet well understood. We address several aspects of the structure-dynamics relationship. Aim 1: In a joint NMR experimental -computational refinement approach we seek to improve the representation of ps-ns timescale dynamics in protein structural ensembles. A statistical and an information theory based approach will be employed to evaluate the experimental restraints and the number of local conformers to be used in the structure refinement. The results will be compared to unrestrained molecular dynamics simulations and to order parameters derived from NMR relaxation measurements. The structural ensembles will be useful for ligand and protein docking calculations in drug design. Aim 2: Our study seeks to reveal design principles that allow a coupling between protein loops and the fluctuations of core structures. Again, both solution NMR experimental and computational strategies will be combined for several proteins, including for ubiquitin and for the RhoGTPase binding domain of plexin-B1 (RBD), which has a ubiquitin fold with long loop insertions. The loops as well as the protein core will be manipulated in order to probe possible dynamic coupling between the two. Possible motional coupling across a protein-protein interface will also be examined for the RBD-GTPase complex. Aim 3: The possibility that the global stochastic motion of the protein can affect the local, internal dynamics will be examined using NMR relaxation at different solvent viscosities and long time-scale Langevin/Brownian dynamics simulations. Aim 4: Methods for enhanced sampling of conformational space will be tested and a next generation force field for the molecular dynamics program CHARMM/NAMD will be validated against NMR data. Overall, in this project, several computational and experimental strategies will be brought together in order to provide deep insight into the relationship between protein structures, and internal as well as global protein dynamics. Several of the proteins studied have important roles in oncogenesis and cell metastasis and their further investigation will suggest new avenues for the design of diagnostic or therapeutic agents to combat cancer. PUBLIC HEALTH RELEVANCE: The joint experimental and computational project will provide detailed insight into the interrelationship between protein structure and protein internal and global dynamics. The basic questions addressed are fundamental to the field of protein biophysics and structural biology. The results of this study will help to understand protein function, here specifically of cell signaling proteins. Several of the proteins involved play important roles in cancer development and spreading, and their further investigation will suggest new avenues for the design of diagnostic or therapeutic agents.