Visualizing chemical bonding in biological macromolecules by microcrystal electron diffraction

通过微晶电子衍射可视化生物大分子中的化学键

• 批准号: 10020791
• 负责人: Brent Nannenga
• 金额: $ 19.63万
• 依托单位: ARIZONA STATE UNIVERSITY-TEMPE CAMPUS
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-20 至 2022-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10020791
• 关键词: 3-Dimensional; Accounting; Algorithms; Back; Biological; Charge; Chemical Structure; Collection; Crystallization; Data; Data Collection; Data Set; Development; Disease; Electrons; Endopeptidase K; Enzymatic Biochemistry; Future; HGF gene; Heme Group; Image; Ions; Iron; Lead; Ligands; Maps; Metals; Methodology; Methods; Modeling; Molecular Structure; Pattern; Peptides; Procedures; Proteins; Protocols documentation; R-factor; Resolution; Roentgen Rays; Sampling; Structure; System; Techniques; Thinness; Visualization; Work; biological systems; catalase; chemical bond; computerized data processing; covalent bond; density; electron diffraction; improved; ionic bond; macromolecule; molecular dynamics; neglect; novel strategies; phthalocyanine; small molecule; structural biology; success; three dimensional structure; tool; transmission process

SUMMARY Methods and techniques capable of directly visualizing chemical bonding and charge in biomolecules would add an exciting tool to the field of structural biology. Unlike X-rays, electron diffraction is very sensitive to the bond- charge distribution, especially at lower resolution and small scattering angles, so that electron diffraction has been used on inorganic samples to study and image the charge distribution in chemical bonds, directly mapping out both covalent and ionic bonds. This sensitivity is readily apparent from the large difference between tabulated electron scattering factors for atoms and those for ions. The overall aim of this project is to develop and extend charge-cloud modeling methods to biomolecular structures and couple these procedures with microcrystal electron diffraction (MicroED) data collection and processing for the direct determination of chemical bonding in high-resolution biomolecular structures. The charge-cloud method was initially developed to determine the bonding in an organic small molecule phthalocyanine and used transmission electron diffraction patterns from thin crystals. It was shown that by properly treating electron diffraction data with this method, charge density in the bonds between atoms could be seen in a 2D projection of the organic molecular structure. To extend this method to 3D structures of biological molecules, high-quality 3D electron diffraction data will be required. Therefore, we will make use of the MicroED method for electron diffraction data collection on several model microcrystalline samples. Since its development, MicroED has been shown to produce high-quality electron diffraction data that yields high-resolution 3D structures of biological molecules. The combined method of MicroED data collection and processing along with charge-cloud refinement of low order Bragg reflections will yield a straightforward, efficient, widely accessible technique for the direct visualization of bonding in biological samples.

概括 能够直接在生物分子中直接可视化化学键和电荷的方法和技术会增加 结构生物学领域的令人兴奋的工具。与X射线不同，电子衍射对键非常敏感 电荷分布，尤其是在较低分辨率和较小的散射角度，因此电子衍射具有 用于研究和成像化学键中的电荷分布，直接映射 共价键和离子键。从列表的巨大差异来看，这种敏感性很明显 原子和离子的电子散射因子。该项目的总体目的是开发和扩展 对生物分子结构的电荷云建模方法，并将这些程序与微晶搭配 电子衍射（微型）数据收集和处理，用于直接确定化学键合中的化学键 高分辨率生物分子结构。最初开发了电荷云方法来确定 在有机小分子邻苯丙氨酸中键合，并从中使用的透射电子衍射图案 薄晶体。结果表明，通过使用这种方法正确处理电子衍射数据， 原子之间的键可以在有机分子结构的2D投影中看到。扩展这一点 生物分子的3D结构的方法，将需要高质量的3D电子衍射数据。 因此，我们将利用几种模型上电子衍射数据收集的微型方法 微晶样品。自从其开发以来，已显示微型产生高质量的电子 产生生物分子的高分辨率3D结构的衍射数据。合并的方法 微型数据收集和处理以及低阶bragg反射的充电云的完善将 产生一种直接，高效，可访问的技术，以直接可视化生物学 样品。