Solid state NMR spectroscopy: chemical and biological applications

核磁共振（NMR）光谱是研究分子结构、动力学和化学键合的强大分析技术。到目前为止，最成功的NMR应用集中在检测核自旋量子数为1/2的原子核。然而，元素周期表中超过70%的元素具有核自旋量子数大于1/2的同位素，例如Na-23（自旋-3/2），K-39（自旋-3/2）和O-17（自旋-5/2）。这些原子核被称为四极核。由于四极核具有不利的核性质，它们中的许多经常被认为是“NMR不可见的”。我们的研究计划的主要目标是开发新的NMR技术，使四极核可及，此外，将这些技术应用于生物分子系统，如DNA和离子通道蛋白质。四极核的核磁共振一直是核磁共振研究领域中最具挑战性的问题之一。我们的研究可能在两个方面提供新的可能性：（1）直接检测DNA和离子通道蛋白质中的碱金属离子;（2）开发O-17 NMR作为生物结构的新探针。这些代表了具有相当大潜力的新研究方向。成功的应用将为化学和生物化学中几个尚未解决的问题带来新的曙光。拟议的研究也将对NMR光谱学的总体发展产生重大影响。在这个研究项目中培训的学生将学习有关DNA和蛋白质样品的制备和先进的生物物理表征方法的应用的重要知识，以及批判性思维技能，无论是在学术或工业环境中取得成功。

Nuclear magnetic resonance (NMR) spectroscopy is a powerful analytical technique for studying molecular structure, dynamics and chemical bonding. To date most successful NMR applications have focused on detection of atomic nuclei with a nuclear spin quantum number of ½. However, over 70% of the elements in the Periodic Table have isotopes whose nuclear spin quantum number is greater than ½ such as Na-23 (spin-3/2), K-39 (spin-3/2) and O-17 (spin-5/2). These nuclei are known as quadrupolar nuclei. Because quadrupolar nuclei possess unfavorable nuclear properties, many of them have often been considered "NMR invisible". The primary objective of our research program is to develop new NMR techniques to make quadrupolar nuclei accessible and, furthermore, to apply these techniques to biomolecular systems such as DNA and ion channel proteins. NMR for quadrupolar nuclei has remained one of the most challenging problems to experimentalists in the field of NMR research. Our proposed research may provide new possibilities in two general areas: (1) direct detection of alkali metal ions in DNA and ion channel proteins and (2) development of O-17 NMR as a new probe to biological structures. These represent new research directions with considerable potential. Successful applications will shed new light into several unsolved problems in chemistry and biochemistry. The proposed research will also have a significant impact on the general development of NMR spectroscopy. The students trained in this research program will learn important knowledge about preparation of DNA and protein samples and application of advanced biophysical characterization methods, as well as critical thinking skills to be successul in either academic or industrial environment.