International Research Fellowship Program: Invisible, Excited State Structures from Relaxation Dispersion NMR Spectroscopy

0853108 Latham该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。国际研究奖学金计划使美国科学家和工程师能够在国外进行9到24个月的研究。 该计划的奖项提供了联合研究的机会，并使用独特的或互补的设施，专业知识和国外的实验条件。该奖项将支持24个月的研究奖学金博士迈克尔P。莱瑟姆与博士刘易斯E。确定生物分子的模型是结构生物学的主要目标，这些模型可以用来深入了解生物分子的功能。一般来说，生物分子的高分辨率模型只能获得低能量，基态构象。虽然这些静态基态结构提供了丰富的信息，但也必须研究生物分子的动态性质，以更全面地了解结构，功能和机制之间的关系。因此，如果不理解基态结构向更高能量激发态的偏移，可能无法完全理解蛋白质功能。然而，结构生物学研究的激发态是复杂的低人口和短暂的性质，这些往往？隐形的？激发态NMR光谱学是独特的能够在很宽的时间尺度上定点探测蛋白质动力学。强大的NMR弛豫色散技术对低布居激发态的存在特别敏感。这项建议的目的是开发和应用这些技术的结构研究的“看不见的”激发态的折叠途径的两个模块域。具体而言，正在开发新的弛豫分散方法，补充其他最近描述的技术，探测激发态的结构，使用NMR化学位移值和残余偶极耦合。这些方法，然后扩展到生成模型的低能量，对途径折叠中间体的Fyn SH 3和人类HYPA/FBP 11 FF域，这将代表一些折叠中间体和？隐形的？激发态虽然这里使用的技术最初应用于蛋白质折叠，但它们应该普遍适用于酶催化和蛋白质配体结合的研究。此外，人们越来越重视蛋白质错误折叠在疾病状态中的作用，如囊性纤维化、阿尔茨海默病？的疾病和朊病毒引起的疾病。与囊性纤维化的情况一样，一些遗传疾病与蛋白质错误折叠密切相关，导致形成稳定的非活性中间状态。因此，这项研究可以打开大门，其他结构研究的“看不见的”中间状态涉及蛋白质折叠/错误折叠与疾病状态。

0853108LathamThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four-month research fellowship by Dr. Michael P. Latham to work with Dr. Lewis E. Kay at the University of Toronto in Canada.Determining models for biomolecules is a primary goal in structural biology, and these models can be used to gain insight into biomolecular function. Generally, high-resolution models of biomolecules are only obtainable for low energy, ground state conformations. While these static ground state structures offer a wealth of information, the dynamic nature of biomolecules must also be investigated to more fully understand the relationship between structure, function and mechanism. Thus, protein function may not be fully appreciated without an understanding for the excursion of ground state structures to higher energy excited states. However, structural biology studies of excited states are complicated by the low populations and transient nature of these often ?invisible? excited states. NMR spectroscopy is uniquely capable of site-specifically probing protein dynamics over a wide range of timescales. The powerful NMR relaxation dispersion technique is particularly sensitive to the presence of lowly populated excited states. The objective of this proposal is to develop and apply these techniques to structural studies of 'invisible' excited states in the folding pathway of two modular domains. Specifically, new relaxation dispersion methods are being developed, which complement other recently described techniques, to probe the structures of excited states using NMR chemical shift values and residual dipolar couplings. These methods are then extended to generate models for low energy, on-pathway folding intermediates of the Fyn SH3 and human HYPA/FBP11 FF domains, which will represent some of the first pictures of folding intermediates and ?invisible? excited states. While the techniques utilized here are initially applied to protein folding, they should be generally applicable in the study of enzyme catalysis and protein ligand binding. Moreover, there is an increased appreciation for the role of protein misfolding in disease states, such as cystic fibrosis, Alzheimer?s disease and diseases resulting from prions. As the case with cystic fibrosis, some genetic diseases are intimately coupled with protein misfolding, resulting in the formation of stable, inactive intermediate states. Thus, this study could open the door to other structural studies of 'invisible' intermediate states involved in protein folding/misfolding associated with disease states.