DISTANCE DISTRIBUTIONS FROM ANALYSIS OF DQC ESR DATA USING REGULARIZATION METH

使用正则化方法分析 DQC ESR 数据的距离分布

• 批准号: 7723905
• 负责人: YUN-WEI CHIANG
• 金额: $ 0.16万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7723905
• 关键词: Computer Retrieval of Information on Scientific Projects Database; Data; Data Quality; Funding; Grant; Institution; Label; Membrane Proteins; Methods; Muramidase; Proteins; Research; Research Personnel; Resources; Shapes; Signal Transduction; Solvents; Source; Spin Labels; Structure; Testing; Time; United States National Institutes of Health; Water; Work; insight; mutant; stoichiometry

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Distance distributions provide valuable structural information that could help to provide insight into the static structure of membrane proteins and conformationally heterogeneous water soluble proteins as well as fluctuations in these structures. Another important aspect of determining distance distributions is the case of more than two spins. For example, in fully-labeled KcsA channels there are four spin-labels, with two possible distances due to symmetry considerations. The two distances and the stoichiometry could be used as additional parameters that could help to determine distance distributions with a high degree of confidence. These distributions could then be used to find the change in distances upon channel gating when only a fraction of the channels is in the open state. T4-Lysozyme served as testing ground for determining methods useful for solving the inverse problem of finding the distributions from the DQC-ESR spectra. High-quality data were obtained on T4-L 65/135 and 61/135 mutants at 17GHz with use of deuterated solvents. The DQC signals with excellent SNR were recorded on a time-scale of 6s and analyzed by the Tikhonov regularization method. The shapes of the distributions in this work are consistent with the distributions found in our previous study of T4-L by trial and error. In the theoretical part of this work, regularization methods were shown to outperform SVD methods. A direct conversion of DQC-ESR signals into distance distributions by the Tikhonov regularization method was facilitated by obtaining the regularization parameter from the L-curve criterion.

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这不一定是调查员的机构。 距离分布提供了有价值的结构信息，可以帮助您深入了解膜蛋白的静态结构和构型异质水溶性蛋白以及这些结构中的波动。确定距离分布的另一个重要方面是两个以上的旋转情况。例如，在完全标记的KCSA通道中，有四个自旋标记，由于对称考虑因素，有两个可能的距离。两个距离和化学计量学可以用作附加参数，可以帮助以高度的置信度确定距离分布。然后，当仅一小部分通道处于空旷状态时，这些分布可用于在通道门控时找到距离的变化。 T4-淋放酶是确定用于解决DQC-ESR光谱分布的反问题的方法的测试基础。 使用氘化溶剂，在17GHz的T4-L 65/135和61/135突变体上获得了高质量的数据。具有出色SNR的DQC信号在6s的时间尺度上记录，并通过Tikhonov正则化方法进行分析。这项工作中分布的形状与我们先前对T4-L研究中通过反复试验发现的分布相一致。在这项工作的理论部分中，正则化方法显示出优于SVD方法。 通过从L-Curve标准获得正则化参数来促进DQC-ESR信号通过Tikhonov正则方法直接转换为距离分布。