Deuteron Nuclear Magnetic Resonance Studies of Oriented Proteins and Model Compou

描述(由申请人提供)：这是一项建议，将为固态氚核磁共振(核磁共振)开发的技术应用于模型化合物和小蛋白质定向体系中的分子动力学的定量研究。这包括开发和测试新的脉冲序列以提高特定位置的光谱分辨率，设计现实的、解释相关运动的新运动模型，以及提供记录良好、易于使用的软件来分析一般的生物分子运动。即使大多数生物学意义重大的运动(例如，酶催化、分子识别等)由于固体核磁共振在室温附近的水溶液中发生，因此目前对固体核磁共振方法研究生物动力学有很大的兴趣。一个动机是，大生物分子中的局部内部运动肯定与它们的功能有关，但由于整个分子缓慢的整体翻滚的干扰，很难用溶液状态的核磁共振来研究。第二个动机是准确确定不同运动过程的激活能，这可以提供关于折叠蛋白质复杂势能景观中最小能量路径的有用信息，通常需要在水溶液无法达到的广泛温度范围内进行测量。第三个动机是，与取向膜中蛋白质和小分子运动相关的运动时间尺度往往太长，不能用全分子动力学模拟来研究，但很容易被通常用于描述固体中运动的适当的模拟模型所访问。计算机技术的最新进展允许使用复杂的运动模型来模拟核磁共振谱线形状和自旋弛豫行为，而就在几年前，这些模型还被认为计算太昂贵。这种模型的一个问题是它们有大量的可调参数：很少有研究报告系统地评估给定模型中的哪些参数可以从什么样的实验核磁共振数据中可靠地确定。第二个问题是，设计一个复杂的模型需要设计者非常熟悉求解大型耦合微分方程组的复杂数学程序。本提案中描述的图形用户界面通过向用户提供用于评估参数可靠性的高级统计工具，并允许用户尽可能地以化学直观的术语指定运动轨迹和速率，从而解决了这两个问题。因此，它将极大地促进非固态核磁共振专家开发这一重要技术的能力。 公共卫生相关性：生物活性大分子中的局部运动对其功能至关重要。因此，对这些运动的详细理解可以通过拟议的实验和相关的计算机分析来获得，可以显著提高我们对许多神经退行性疾病的根本原因的理解，如阿尔茨海默氏症和帕金森氏症，这些疾病是由异常的微观动力学引起的。

DESCRIPTION (provided by applicant): This is a proposal to adapt techniques developed for solid state deuteron nuclear magnetic resonance (NMR) to quantitative investigations of molecular dynamics in oriented systems of model compounds and small proteins. This includes developing and testing new pulse sequences to improve site-specific spectral resolution, designing realistic, new motional models that account for correlated motions, and providing well documented, easy to use software for analysis of biomolecular motion in general. Even though most biologically significant motions (e.g., enzyme catalysis, molecular recognition, etc.) occur near room temperature in aqueous solutions, there are compelling reasons for the current intense interest in solid state NMR methodology for studying biodynamics. One motivation is the fact that local, internal motions in large biomolecules are surely relevant to their function, but are difficult to study by solution state NMR due to interference from slow overall tumbling of the whole molecule. A second motivation is that accurate determination of the activation energies for different motional processes, which can provide useful information about minimum energy pathways through the complex potential energy landscape of a folding protein, typically requires measurements over a wide range of temperatures not accessible with aqueous solutions. A third motivation is that the motional time scales relevant for motion of proteins and small molecules in oriented membranes are often too long to be investigated by full molecular dynamic simulations, but are readily accessible to simulation suitably adapted models commonly used to describe motion in solids. Recent advances in computer technology permit simulations of NMR line shapes and spin relaxation behavior to be carried out using complex motional models that only a few years ago would have been deemed too computationally expensive. One problem with such models is their large number of adjustable parameters: few studies have been reported that assess in a systematic manner which parameters in a given model can be determined reliably from what kinds of experimental NMR data. A second problem is that designing a complex model requires significant familiarity on the part of the designer with intricate mathematical procedures for solving large sets of coupled differential equations. The graphical user interface described in this proposal addresses both these problems by providing users with advanced statistical tools for assessing parameter reliability, and allowing the user wherever possible to specify motional trajectories and rates in chemically intuitive terms. Thus, it will greatly facilitate the ability of non-specialists in solid state NMR to exploit this important technique. PUBLIC HEALTH RELEVANCE: Local motions in biologically active macromolecules are crucial for their function. Thus the detailed understanding of these motions, which can be gained using the proposed experiments and associated computer analysis, could significantly improve our understanding of the root causes of many neurodegenerative diseases such as Alzheimer's and Parkinson's, that result from abnormal microscopic dynamics.