Distance measurements in the borderline region of applicability of CW EPR and DEER: A model study on a homologous series of spin-labelled peptides
Distance measurements in the borderline region of applicability of CW EPR and DEER: A model study on a homologous series of spin-labelled peptides
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DOI：
10.1016/j.jmr.2007.11.023
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发表时间：
2008-04-01
影响因子：
2.2
通讯作者：
Timmel, C. R.
中科院分区：
文献类型：
--
作者：
Banham, J. E.;Baker, C. M.;Timmel, C. R.
用连续波(CW)和脉冲电子顺磁共振(EPR)方法测量了一系列氮氧自旋标记肽的自旋间距。确定了通过展宽CW谱测量偶极耦合的距离上限和目前优化调整的双电子共振(DER)装置的距离下限，发现两者都在1.6-1.9 nm左右。综述了由连续波谱线展宽确定距离和相应分布的方法，并对其进行了进一步的发展。此外，工作表明，对于鹿的测量，对于小于约2 nm的自旋间距离的分析需要一个修正因子，并且这是使用密度矩阵形式计算的。(C)2007 Elsevier Inc.保留所有权利。
Inter-spin distances between 1 nm and 4.5 nm are measured by continuous wave (CW) and pulsed electron paramagnetic resonance (EPR) methods for a series of nitroxide-spin-labelled peptides. The upper distance limit for measuring dipolar coupling by the broadening of the CW spectrum and the lower distance limit for the present optimally-adjusted double electron electron resonance (DEER) set-up are determined and found to be both around 1.6-1.9 nm. The methods for determining distances and corresponding distributions from CW spectral line broadening are reviewed and further developed. Also, the work shows that a correction factor is required for the analysis of inter-spin distances below approximately 2 nm for DEER measurements and this is calculated using the density matrix formalism. (c) 2007 Elsevier Inc. All rights reserved.