Correlated Motions of Folded and Non-Folded Proteins by NMR Spectroscopy and Computation

在原子水平上的蛋白质动力学的详细信息是了解蛋白质的稳定性和功能的基本生物物理的重要性。 本研究的总体目标是探索和发展新的方法，用于全面描述折叠和非折叠蛋白质系统的复杂动力学，并证明其适用于生物学上重要的系统。 天然未折叠蛋白质在广泛的生物物理和生物化学过程中起着至关重要的作用。 最近的NMR残余偶极耦合测量未折叠的蛋白质的分析表明，这些状态可以很好地表征为局部偏向于其骨架二面角的氨基酸类型的函数的构象合奏。这个项目将分析大量的各种各样的这样的合奏通过统计方法，评估内部的翻译和重定向的相关行为。该分析将与动态NMR参数和热力学性质相关联。与折叠态行为的比较将有助于了解蛋白质稳定性的决定因素。 蛋白质中的运动模式通常表现出集体特征。 鉴于最近的实验NMR残余偶极耦合和弛豫数据，以及在构象采样方法和简化描述的reorientational弹性网络模型的进展，这些运动的性质和熵的影响将进行探讨。将对MDM 2蛋白及其与其他多肽的相互作用进行NMR实验。该项目将产生新的计算，统计力学和NMR光谱概念，用于表征折叠和非折叠蛋白质状态，这将增强对蛋白质行为和功能的理解，并作为具有新特性的蛋白质工程的输入。 该项目将为研究生和博士后研究人员提供跨学科培训和研究机会，包括来自人口统计学上代表性不足的群体的学生，包括女性，非洲裔美国人，美洲原住民印第安人，西班牙裔和（美国）亚洲/太平洋岛民研究生。研究方法和结果将纳入高级本科生和研究生课程的生物物理学和生物分子光谱学。PI将参加NHMFL针对高中和大专学生的强大外展计划以及夏季本科研究计划。 该项目由生物科学理事会分子和细胞生物科学部的分子生物物理学和数学和物理科学理事会化学部的实验物理化学计划共同支持。

Detailed information on protein dynamics at an atomic level is of fundamental biophysical importance for understanding protein stability and function. The overall goal of this research is the exploration and development of new methods for a comprehensive description of complex dynamics of folded and non-folded protein systems and to demonstrate their applicability to biologically important systems. Natively unfolded proteins play a vital role in a wide range of biophysical and biochemical processes. Recent analysis of NMR residual dipolar coupling measurements of unfolded proteins suggest that these states can be well characterized by conformational ensembles that are locally biased in their backbone dihedral angles as a function of the amino-acid types. This project will analyze a large variety of such ensembles by statistical methods that assess the internal translational and reorientational correlation behavior. This analysis will be linked to dynamic NMR parameters and thermodynamic properties. Comparison with the folded state behavior will give useful insights into determinants of protein stability. Motional modes in proteins often exhibit a collective character. The nature of these motions and their entropic implications will be explored in view of recent experimental NMR residual dipolar coupling and relaxation data as well as advances in conformational sampling methods and simplified descriptions in terms of reorientational elastic network models. NMR experiments will be performed on the protein MDM2 and its interactions with other polypeptides. This project will produce new computational, statistical mechanical, and NMR spectroscopic concepts for the characterization of folded and non-folded protein states, which will enhance the understanding of protein behavior and function and serve as input for the engineering of proteins with new properties. The project will provide interdisciplinary training and research opportunities for graduate students and postdoctoral researchers, including students from demographically underrepresented groups, including female, African-American, Native American Indian, Hispanic, and (US) Asian/Pacific Islander graduate students. Research methods and results will be incorporated into advanced undergraduate and graduate courses on biophysics and biomolecular spectroscopy. The PI will participate in NHMFL's strong outreach programs for high school and junior college students and a summer undergraduate research program. This project is jointly supported by Molecular Biophysics in the Division of Molecular and Cellular Biosciences in the Directorate for Biological Sciences and the Experimental Physical Chemistry Program in the Division of Chemistry in the Mathematical and Physical Sciences Directorate.