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.

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 结合高和低ESR频率的多频率方法可以分解影响通过定点自旋标记（SDSL）标记的蛋白质上的每个位点标记的复杂动态模式。 在最近使用诱变剂对T4溶菌酶进行的一项研究中，在不同的残基上连接了自旋标签，我们表明高场/高频-ESR（HFHF-ESR）实验可以用微观有序宏观无序（MOMD）模型满意地描述，其中仅存在内部动力学。 缓慢松弛局部结构（SRLS）模型包括整体翻滚率和内部模式的拟合参数。 MOMD模型是SRLS模型的一种极限情况，其中整体翻滚太慢而不会影响光谱的外观。 在9 GHz频谱的较慢时间尺度上，较快的内部模式和较慢的整体翻滚都很重要。 这些研究提供了证据的潜力，多频ESR映射出的动态结构，在一个网站到网站的基础上，一个大分子。 该中心最近安装了新的HFHF-ESR连续波光谱仪，其信噪比和温度稳定性上级以前的版本，这将使我们能够研究系统的动态模式，在9至240 GHz的频率范围内提高灵敏度和吞吐量。 频谱分析的频率范围内的可用性，虽然一个重大的计算挑战，将提供详细的见解系统的动态模式。 我们最初在95 GHz开发的所有谐振器的连续可变耦合的实现将是进一步提高我们HFHF ESR光谱仪灵敏度的关键进步。