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

原子水平上蛋白质动力学的详细信息对于理解蛋白质的稳定性和功能具有基本的生物物理学重要性。本研究的总体目标是探索和发展新的方法，以全面描述折叠和非折叠蛋白质系统的复杂动力学，并证明它们对生物学重要系统的适用性。天然未折叠蛋白在广泛的生物物理和生化过程中发挥着重要作用。最近对未折叠蛋白质的核磁共振剩余偶极偶联测量的分析表明，这些状态可以很好地表征为构象集合，它们的主二面角局部偏置，作为氨基酸类型的函数。该项目将通过评估内部平移和重定向相关行为的统计方法分析大量此类集成。该分析将与动态核磁共振参数和热力学性质联系起来。与折叠态行为的比较将对蛋白质稳定性的决定因素提供有用的见解。蛋白质的运动模式常常表现出一种集体特征。这些运动的性质和它们的熵含义将根据最近的实验核磁共振残余偶极耦合和弛豫数据，以及构象采样方法的进展和简化描述的重新定向弹性网络模型来探讨。核磁共振实验将对MDM2蛋白及其与其他多肽的相互作用进行研究。该项目将为折叠和非折叠蛋白质状态的表征提供新的计算、统计力学和核磁共振光谱概念，这将增强对蛋白质行为和功能的理解，并为具有新特性的蛋白质工程提供输入。该项目将为研究生和博士后研究人员提供跨学科的培训和研究机会，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、非裔美国人、美洲印第安人、西班牙裔和（美国）亚洲/太平洋岛民研究生。研究方法和成果将被纳入生物物理学和生物分子光谱学的高级本科和研究生课程。PI将参与NHMFL针对高中和大专学生的强大推广计划以及夏季本科生研究计划。该项目由生物科学理事会分子与细胞生物科学部的分子生物物理学和数学与物理科学理事会化学部的实验物理化学项目共同支持。

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.