在CODEX实验中的放松诱导的双极交换与重新合 (RIDER) 扭曲
Alexey Krushelnitsky1, Kay Saalwächter1
1Institute of Physics, Martin-Luther-University Halle-Wittenberg, 06120 Halle, Germany.
Magnetic resonance (Gottingen, Germany)
|October 31, 2023
概括
由于RIDER效应,化学转移异构 (CSA) 和二极CODEX实验可能具有挑战性. 使用过器和共弦信号组件的新方法消除了RIDER扭曲,揭示了蛋白质缺乏毫秒级的全球运动.
科学领域:
- 固态核磁共振 (NMR) 光谱学. 固态核磁共振 (NMR) 光谱学.
- 蛋白质动力学和分子运动分析.
背景情况:
- 化学转移异构性 (CSA) 和双极CODEX实验提供了对毫秒-秒时间尺度上的分子重定向的见解.
- 这些实验容易受到RIDER (放松诱导的双极交换与重新合) 效应的影响,这可能导致对分子运动的误解.
研究的目的:
- 在CSA和双极CODEX实验中调查RIDER扭曲的起源,即使在脱条件下.
- 提出和验证消除RIDER效应的方法,以便准确分析分子运动.
主要方法:
- 实施额外的过器来抑制对C-H RIDER负责的反相连贯性.
- 仅记录CODEX信号的cosine组成部分,它对RIDER扭曲的敏感性较小.
- 对模型物质和微晶13C/15N丰富蛋白质 (GB1和SH3) 进行实验.
主要成果:
- 标准CSA和双极CODEX对蛋白质的实验显示了一个误导性的快速衰变信号组件,被误解为全球缓慢运动.
- 没有RIDER的实验设置导致了平坦的混合时间依赖.
- 这表明研究的蛋白质在毫秒时间尺度上不表现出全球运动.
结论:
- RIDER扭曲可以显著阻碍CODEX实验中分子移动性参数的准确确定.
- 提出的方法有效地消除了RIDER工件,允许对分子动态进行可靠的评估.
- 蛋白质GB1和SH3在毫秒时间尺度上没有经历全球运动.
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