MULTIFREQUENCY ESR STUDIES OF PROTEIN DYNAMICS T4 LYSOZYME

T4 溶菌酶蛋白质动力学的多频 ESR 研究

• 批准号: 8363927
• 负责人: KEITH A EARLE
• 金额: $ 0.46万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8363927
• 关键词: Affect; Appearance; Complex; Coupling; Disease model; Frequencies; Funding; Grant; Label; Maps; Microscopic; Modeling; Muramidase; Mutagens; National Center for Research Resources; Noise; Principal Investigator; Protein Dynamics; Proteins; Research; Research Infrastructure; Resources; Signal Transduction; Site; Source; Spectrum Analysis; Spin Labels; Structure; System; Technology; Temperature; Time; United States National Institutes of Health; base; cost; improved; insight; macromolecule; research study

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. A multifrequency approach combining high and low ESR frequencies can enable a decomposition of the complex dynamic modes affecting each site label on a protein labeled via site-directed spin-labeling (SDSL). In a recent study on T4 lysozyme using mutagens, to which a spin label is attached at different residues, we showed that the high-field/high-frequency-ESR (HFHF-ESR) experiments could be satisfactorily described by the microscopic order macroscopic disorder (MOMD) model in which only the internal dynamics is present. The slowly relaxing local structure (SRLS) model includes fitting parameters for the overall tumbling rates and internal modes. The MOMD model is a limiting case of SRLS model where the overall tumbling is too slow to affect the appearance of the spectrum. On the slower time scale of the 9GHz spectra both the faster internal modes and the slower overall tumbling are important. These studies have provided evidence for the potential of multifrequency ESR to map out the dynamic structure, on a site to site basis, of a macromolecule. The center has recently installed new HFHF-ESR cw spectrometers with superior signal to noise and temperature stability to previous versions, which will allow us to study the dynamic modes of the system with improved sensitivity and throughput capability over a range of frequencies from 9 to 240GHz. The availability of spectra for analysis over a range of frequencies, although a significant computational challenge, will provide detailed insights into the dynamic modes of the system. The implementation of continuously variable coupling to all of our resonators originally developed at 95GHz will be a crucial advance to further improve the sensitivity of our HFHF ESR spectrometers.

该副本是利用资源的众多研究子项目之一 由NIH/NCRR资助的中心赠款提供。对该子弹的主要支持 而且，副投影的主要研究员可能是其他来源提供的 包括其他NIH来源。 列出的总费用可能 代表subproject使用的中心基础架构的估计量， NCRR赠款不直接向子弹或副本人员提供的直接资金。 结合高和低ESR频率的多频方法可以使复杂的动态模式的分解能够影响通过位置定向的自旋标记（SDSL）标记的蛋白质上的每个位点标记。 在使用诱变剂上附着在不同残基上的诱变剂上的T4溶菌酶的最新研究中，我们表明，高场/高频率-ESR（HFHF-ESR）实验可以通过显微镜级别宏观疾病（MOMD）模型令人满意地描述，其中仅存在内部动力学。 缓慢放松的局部结构（SRLS）模型包括用于整体翻滚速率和内部模式的拟合参数。 MOMD模型是SRLS模型的限制案例，其中总体翻滚太慢，无法影响光谱的外观。 在9GHz光谱的时间尺度较慢，更快的内部模式和整体翻滚较慢都很重要。 这些研究为多频ESR的潜力提供了证据，以将大分子的位置绘制出动态结构。 该中心最近安装了新的HFHF-ESR CW光谱仪，具有较高信号的噪声和温度稳定性，这将使我们能够在9到240GHz的一系列频率上以提高灵敏度和吞吐量能力来研究系统的动态模式。 在一系列频率范围内的分析的可用性，尽管重大的计算挑战将为系统的动态模式提供详细的见解。 最初在95GHz开发的所有共振器的连续可变耦合实施将是至关重要的进步，以进一步提高HFHF ESR ESR光谱仪的敏感性。