The spatial effect of protein deuteration on nitroxide spin-label relaxation: implications for EPR distance measurement.
The spatial effect of protein deuteration on nitroxide spin-label relaxation: implications for EPR distance measurement.
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DOI：
10.1016/j.jmr.2014.09.010
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发表时间：
2014-11
影响因子：
2.2
通讯作者：
Norman, David G.
中科院分区：
文献类型：
--
作者：
El Mkami, Hassane;Ward, Richard;Bowman, Andrew;Owen-Hughes, Tom;Norman, David G.
回声衰减曲线在分段氘化的八聚体蛋白上测量。从每个数据集提取回波消相时间（Tm）。自旋弛豫与质子的空间分布有关。测定了Tm和T1的温度和浓度依赖性。讨论了氘化对弛豫和偶极耦合的影响。脉冲电子-电子双共振（PELDOR）结合定点自旋标记是一种强有力的技术，用于阐明蛋白质或核酸、大分子结构和相互作用。电子顺磁共振固有的高灵敏度使得可以测量少量的生物大分子，然而，短的弛豫时间限制了灵敏度和使用该技术可以测量的距离大小。在PELDOR实验中，电子自旋回波的持续存在是距离测量最关键的限制之一。在50 K左右的温度下，影响回波持续时间的主要因素之一是电子自旋回波消相时间（Tm），因此，自旋标签之间的灵敏度和可测量距离。使用氘化溶剂延长Tm已成为常规做法，最近已证明底层蛋白质的氘化可显著延长Tm。在这里，我们研究了潜在蛋白质的片段氘化的空间效应，并探讨了高度氘化系统的浓度和温度依赖性。
Echo decay curves were measured on segmentally deuterated, octameric proteins. The echo dephasing time (Tm) was extracted from each data set. Spin relaxation was correlated to the spatial distribution of protons. Temperature and concentration dependence of Tm and T1 was measured. The effect of deuteration on relaxation and dipolar coupling were discussed. Pulsed electron–electron double resonance (PELDOR) coupled with site-directed spin labeling is a powerful technique for the elucidation of protein or nucleic acid, macromolecular structure and interactions. The intrinsic high sensitivity of electron paramagnetic resonance enables measurement on small quantities of bio-macromolecules, however short relaxation times impose a limit on the sensitivity and size of distances that can be measured using this technique. The persistence of the electron spin-echo, in the PELDOR experiment, is one of the most crucial limitations to distance measurement. At a temperature of around 50 K one of the predominant factors affecting persistence of an echo, and as such, the sensitivity and measurable distance between spin labels, is the electron spin echo dephasing time (Tm). It has become normal practice to use deuterated solvents to extend Tm and recently it has been demonstrated that deuteration of the underlying protein significantly extends Tm. Here we examine the spatial effect of segmental deuteration of the underlying protein, and also explore the concentration and temperature dependence of highly deuterated systems.
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使用脉冲EPR光谱与位置定向的自旋标记探测（H3-H4）2组蛋白四聚体结构。
影响因子：
14.9
作者：
Bowman A;Ward R;El-Mkami H;Owen-Hughes T;Norman DG
通讯作者：
Norman DG
影响因子：
2.2
作者：
NAKAGAWA, K;CANDELARIA, MB;EATON, GR
通讯作者：
EATON, GR
影响因子：
4.4
作者：
Nevzorov, AA;Freed, JH
通讯作者：
Freed, JH
影响因子：
1.7
作者：
Zecevic, A;Eaton, GR;Lindgren, M
通讯作者：
Lindgren, M
DOI：
10.1016/j.jmr.2010.08.002
发表时间：
2010-11
期刊：
Journal of magnetic resonance (San Diego, Calif. : 1997)
影响因子：
--
作者：
Ward R;Bowman A;Sozudogru E;El-Mkami H;Owen-Hughes T;Norman DG
通讯作者：
Norman DG