SLOW-TUMBLING ANALYSIS FOR 2D-ELDOR FOR TWO COUPLED NITROXIDES

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。 ACERT对测量两个NO自旋之间的距离有相当大的兴趣， 考虑到两个自旋标记之间的电子偶极相互作用，从2D-ELDOR光谱的膜中的探针。其优点是，在这里可以在环境温度下测量这些距离。目前，还没有一种计算方法能严格考虑两个自旋探针之间的相互作用，即两个电子和两个原子核之间的相互作用。为了实现这一点，由Schneider和Freed开发的技术适用于模拟慢运动CW EPR谱的一个自旋标签，即一个电子耦合到一个核，详细研究了可能的扩展使用Lanczos算法。首先，通过扩展起始矢量，并考虑附加核与电子的相互作用，对一个电子自旋与两个核自旋耦合的系统进行了推广，并在一个样品系统上进行了测试，结果令人满意，发表于：S.K. Misra，2007年。用随机刘维尔方程模拟电子自旋耦合到两个任意自旋核的慢运动CW EPR谱：刘维尔超算子的矩阵元，J. Mag. Reson。189，59-77.

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. There is a considerable interest at ACERT to measure distances between two NO spin probes in membranes from 2D-ELDOR spectra taking into account the electronic dipolar interaction between two spin labels. The advantage is that here one can measure these distances in membranes at ambient temperatures. At present, there is available no computational technique to rigorously take into account the interaction between two spin probes, that is between two electrons and two nuclei for 2D-ELDOR. In order to accomplish this, the technique developed by Schneider and Freed applicable to simulation of slow motion CW EPR spectrum for one spin label, that is one electron coupled to one nucleus, was studied in detail for possible extension using the Lanczos algorithm. First, the extension was made for a system of one electron spin coupled to two nuclear spins by extending the starting vector, and taking into account the interaction of the additional nucleus with the electron. This extension was tested on a sample system, and was found to work satisfactorily, and published: S.K. Misra, 2007. Simulation of slow-motion CW EPR spectrum using Stochastic Liouville equation for an electron spin coupled to two nuclei with arbitrary spins: Matrix elements of the Liouville superoperator, J. Mag. Reson. 189, 59-77.