DEVELOPMENT OF 2D AND 3D NMR FOR STUDIES OF BIOMOLECULES

这个项目的主要目标是开发新的、高分辨率的 核磁共振(核磁共振)方法在研究中的应用 生物分子的结构和动力学，如蛋白质和核酸。 核磁共振波谱已成为研究核磁共振的一种非常有力的工具。 溶液中的生物分子，由于其能够提供详细的 原子水平上的信息核磁共振光谱学可以在多大程度上 用于生物分子的三维结构测定， 分子间相互作用的研究 药物/受体、酶/底物和抗体/抗原复合体，以及 分子碎片动力学的表征，将取决于 能够操纵系统以获得EM所需的信息。这个 生物核磁共振在过去十年中做出的巨大贡献 在生物分子和生物物理过程的研究中 很大程度上是由于不断开发新的或改进的技术 从感兴趣的系统中提取有用数据。 任何核磁共振研究的前提步骤都是指定共振峰 到感兴趣分子中的单个原子核。其中最 目前用于共振分配的有效实验基于 关于各向同性混合的原理。尽管这种方式很受欢迎 在实验中，它们在理论上还没有得到很好的表征。一个目标 对所提出的研究内容进行了详细的分析和研究 各向同性混合实验的各个方面，特别是 采用多频照射的新方案以改善 效率。此外，采用各向同性混合的新实验 我们将探索异核相干转移。 在开发新的核磁共振技术和分析其 根据其特点，进行简化假设是很常见的。然而， 在最近的一些实验中，特别是那些使用Long的实验中 在射频照射期间，要进行更多的 严格的分析，包括核磁共振弛豫现象的影响。 在新的开发过程中考虑松弛过程是至关重要的 旨在分离松弛和连贯效应的实验 调职。这项提案的主要目标之一是推导出一个 将弛豫效应包括在核磁共振模拟中的方便的形式， 并将其用于开发改进的各向同性混合和 相关技术。 而核磁共振是获取详细信息的首选方法 在溶液中生物分子的物理研究中，不幸的是 相对不敏感的技术。建议对此进行调查 有希望的方案来提高各种重要的 各种技术，如各向同性混合、异核相关方法和 松弛时间测量。从理论上讲，新的实验将是 开发的仪器可以将所需的测量时间减少一半。 生物分子系统中的动力学过程通常在 生物功能，因此，有合适的方法是非常重要的 来描述这类现象。核磁共振光谱学是一种非常强大的 获取分子动力学详细信息的工具 碎片。这项提议的一个重要目的是将 从理论上论证了多量子技术的有效性 用于研究化学重组过程。另一个主要目标是 开发有助于异核物质测量的技术 松弛速度。这样的数据对于在功能和功能上的使用将是无价的 蛋白质和核酸等生物分子的结构研究。

The major goal of this project is the development of new, high resolution nuclear magnetic resonance (NMR) methodologies for use in studies of the structure and dynamics of biomolecules such as proteins and nucleic acids. NMR spectroscopy has become an extremely powerful tool for the study of biomolecules in solution, due to its ability to provide detailed information at an atomic level The extent to which NMR spectroscopy can be exploited for three-dimensional structure determinations of biomolecules, the investigation of intermolecular interactions in systems such as drug/receptor, enzyme/substrate and antibody/antigen complexes, and the characterization of the dynamics of molecular fragments, will depend on the ability to manipulate the system to yield EM desired information. The enormous contribution that biological NMR has made during the last decade in the investigation of biomolecules and biophysical processes is due largely to the continuing development of new or improved techniques for extracting useful data from the systems of interest. A prerequisite step in any NMR study is the assignment of resonances to individual nuclei in the molecule of interest. One of the most efficient experiments currently in use for resonance assignment is based on the principle of isotropic mixing. Despite the popularity of such experiments, they have not been well characterized theoretically. One aim of the proposed research is a detailed analysis and development of various aspects of isotropic mixing experiments, in particular, the development of novel schemes employing multiple frequency irradiation to improve the efficiency. Also, new experiments employing isotropic mixing for heteronuclear coherence transfer will be explored. In the development of new NMR techniques and the analysis of their characteristics, it is common to make simplifying assumptions. However, in some of the most recent experiments, especially those employing long periods of radio-frequency irradiation, it is necessary to conduct a more rigorous analysis which includes the effects of NMR relaxation phenomena. It is vital to consider relaxation processes in the development of new experiments designed to separate the effects of relaxation and coherence transfer. One of the major goals in this proposal is to derive a convenient formalism for including relaxation effects into NMR simulations, and to use this for the development of improved isotropic mixing and related techniques. While NMR is the method of choice for obtaining detailed information in physical studies of biomolecules in solution, it unfortunately is a comparatively insensitive technique. It is proposed to investigate promising schemes for improving the sensitivity of various, important techniques such as isotropic mixing, heteronuclear correlation methods and relaxation time measurements. Theoretically, the new experiments to be developed can reduce the required measuring time in half. Dynamical processes in biomolecular systems often play a key role in biological function, and thus it is very important to have suitable methods for characterizing such phenomena. NMR spectroscopy is a very powerful tool for obtaining detailed information on the dynamics of molecular fragments. One important aim of this proposal is to characterize theoretically and demonstrate the usefulness of multiple quantum techniques for studying chemical reorganization processes. Another major goal is to develop techniques which will facilitate the measurement of heteronuclear relaxation rates. Such data would be invaluable for use in functional and structural studies of biomolecules such as proteins and nucleic acids.