碳-13中带-仅检测与动态核极化交换的探测
Abel Cherian Varkey1, Kai Xue2,3, Evgeny Nimerovsky1
1Department of NMR Based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077, Göttingen, Germany.
概括
使用13C旋转的中带仅检测交换 (CODEX) NMR,可以确定蛋白质寡合化. 动态核极化 (DNP) 增强了灵敏度,而旋转扩散则纠正了背景信号,提高了准确性.
科学领域:
- 生物物理化学 生物物理化学
- 结构生物学 结构生物学
- 核磁共振 (NMR) 光谱学 核磁共振 (NMR) 光谱学
背景情况:
- 魔法角旋转的NMR技术,仅检测中心带的交换 (CODEX),确定了具有特定地点标签的分子寡合化.
- 对于使用19F标签的蛋白质,CODEX是有效的,但由于灵敏度低和背景旋转,对13C有限制.
- 在低温下动态核极化 (DNP) 可以增强CODEX的13C旋转灵敏度.
研究的目的:
- 调查13C旋转用于基于CODEX的蛋白质中的寡合体确定.
- 为了提高灵敏度,使用DNP并对自然丰富的13C背景旋转进行校正.
- 展示一种用于回收准确的CODEX衰变曲线的方法.
主要方法:
- 使用只有中带检测的交换 (CODEX) 核磁共振与特定地点的13C标签.
- 在低温下使用动态核极化 (DNP) 来提高灵敏度.
- 应用了质子驱动的旋转扩散 (PDSD) 来纠正自然丰富的13C背景效应.
主要成果:
- 使用PDSD证明了13C自然丰度背景的成功校正.
- 通过分析PDSD光谱中的自相关性峰值衰变,恢复了预期的CODEX衰变曲线.
- 达到高达1500秒的混合时间,使用13C-γ-phenylalanine标签和13C贫的背景.
结论:
- 13C旋转可以有效地用于基于CODEX的蛋白质寡合体确定,并进行适当的灵敏度增强和背景校正.
- 基于PDSD的校正是一种可行的方法,可以减轻自然丰富度旋转的脱相.
- 开发的方法扩大了CODEX NMR用于研究蛋白质结构的适用性.
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