Development of Laser-Mediated Hyper-Sensitive NMR in Liquids

激光介导液体超灵敏核磁共振的发展

• 批准号: 8898152
• 负责人: Silvia Cavagnero
• 金额: $ 14.44万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8898152
• 关键词: Amino Acids; Area; Bioavailable; Biological; Biological Process; Biology; Biomedical Research; Biomolecular Nuclear Magnetic Resonance; Carbon; Cations; Cell Nucleus; Coupled; Coupling; Data; Data Collection; Development; Disease; Dyes; Engineering; Enhancers; Equilibrium; Exhibits; Fiber Optics; Flavin Mononucleotide; Fluorescence; Frequencies; Gases; Generations; Goals; Health; Individual; Investigation; Iodides; Lasers; Liquid substance; Maps; Mediating; Medical; Medicine; Modeling; NMR Spectroscopy; Neurodegenerative Disorders; Nuclear; Photosensitizing Agents; Physiologic pulse; Proteins; Relative (related person); Research; Research Personnel; Resolution; Sampling; Scheme; Science; Side; Solid; Solutions; Solvents; Techniques; Testing; Time; Uncertainty; Vertebral column; Viscosity; Work; analog; base; computerized data processing; cryogenics; data acquisition; design; electron density; experience; instrumentation; interest; irradiation; method development; novel; novel strategies; oxidation; polypeptide; prevent; reconstruction; research study; tool; triplet state; tryptophyltyrosine

DESCRIPTION (provided by applicant): A substantial barrier to progress in many areas of biomedical research is the lack of atomic-resolution structural and dynamic characterization of the biomolecule of interest in solution. The main obstacle is often the insufficient amount of available material or, alternatively, the need to keep the target molecule dilute to prevent its aggregation. The goal of this research is to develop novel tools to significantly increase the sensitivity of NMR spectroscopy in solution via laser-driven photo-chemically induced dynamic nuclear polarization (photo-CIDNP). The instrumentation involved in this work comprises high-power lasers (both continuous-wave and pulsed) coupled, via fiber optic, to a commercial 600 MHz NMR spectrometer equipped with a quadruple-resonance (HFCN) cryogenic probe. The advances enabled by this work will facilitate the tackling of important biological questions of medical significance by many investigators, and will enable high- resolution NMR analysis under mild, physiologically relevant conditions in dilute solution. The proposed research involves extensive method development in heteronuclear correlation photo-CIDNP NMR, including the generation of novel pulse sequences to enable 1, 2 and 3D photo-CIDNP sensitivity-enhanced data collection. Non-uniform sampling (NUS) will be implemented as part of the pulse sequence design and subsequent data reconstruction, for the higher-dimensionality experiments. Longitudinal equilibrium and non- equilibrium magnetization will be enhanced via the photo-CIDNP effect for a variety of spin-1/2 nuclei, primarily 1H, 15N, 13C and 19F. In the case of 13C and 19F, the particularly large hyperfine coupling of the transient radical cations of the biomolecules of interest (which is generated as part of photo-CIDNP) promise to yield extremely large enhancements. Preliminary data on 13C photo-CIDNP are extremely encouraging and support the feasibility of the proposed experiments. We will also develop novel photo-CIDNP photosensitizer dyes and matching experiments to use them. In addition, we will synergistically combine experiments with collaborative efforts involving ab initio electron density and hyperfine-coupling-constant calculations to identify and predict the best-performing dyes. Finally, we will develop pilot approaches employing double laser irradiation schemes, which involve the concerted use of a laser capable of exciting the photo-CIDNP dye in the visible range, and another laser exciting the molecule of interest in the � AE�* transition range. The latter range corresponds to excitation of backbone and side-chain carbonyls of all amino acids, to render them more susceptible to transient oxidation and develop larger sensitivity-enhancement factors in the context of biomedically important polypeptides and proteins.

描述（由适用提供）：在生物医学研究的许多领域中，进步的实质性障碍是缺乏原子分辨率的结构和动态表征在溶液中感兴趣的生物分子。主要的障碍通常是可用材料的数量不足，或者需要保持目标分子稀释以防止其聚集。这项研究的目的是开发新的工具，以通过激光驱动的光化学诱导的动态核极化（Photo-CidNP）显着提高溶液中NMR光谱的灵敏度。这项工作所涉及的仪器包括通过光纤与配备有四倍共振（HFCN）低温探针的600 MHz NMR光谱仪的高功率激光器（连续波和脉冲）结合使用。这项工作启用的进步将有助于解决许多研究者的重要生物学问题，并将在稀释溶液中轻度，身体相关的条件下实现高分辨率的NMR分析。拟议的研究涉及异核相关性照片cidnp NMR的广泛方法开发，包括生成新型脉冲序列以启用1、2和3D photo-cidnp敏感性增强数据收集。非均匀采样（NUS）将作为脉冲序列设计和随后的数据重建的一部分实现，以进行高维实验。纵向平衡和非平衡磁化强度将通过光盘效应增强，以获得各种自旋1/2核，主要1H，15N，13C和19F。在13C和19F的情况下，尤其是感兴趣的生物分子的瞬时激进阳离子（作为光蛋白蛋白的一部分）的瞬时激进阳离子有望产生极大的增强功能。 13c photo-cidnp的初步数据极为令人鼓舞，并支持了拟议的实验的可行性。我们还将开发新颖的Photo-Cidnp光敏剂染料和匹配实验以使用它们。此外，我们将协同结合实验与协作努力涉及从头算电子密度和高精细耦合 - 稳定量计算，以识别和预测表现最佳的染料。最后，我们将采用双激光辐照方案开发飞行员方法，该方法涉及能够在可见范围内激发照片cidnp染料的激光使用，而另一个激光激发了AE*过渡范围中感兴趣的分子。后来的范围对应于所有氨基酸的骨架和侧链羰基的兴奋，以使它们更容易受到短暂氧化的影响，并在生物医学重要的多肽和蛋白质的背景下产生更大的灵敏度增强因子。