以质子检测的固态NMR光谱对40kHz的完全质子化蛋白质进行了魔法角旋转
Donghua H Zhou1, Gautam Shah, Mircea Cormos
1Department of Chemistry, Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Journal of the American Chemical Society
|August 30, 2007
概括
这项研究使用质子检测增强了对大型蛋白质的固态NMR灵敏度. 这种方法提高了对标记均的蛋白质的光谱分配效率,即使样本数量有限.
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:
- 固态NMR可以确定高达10kDa的蛋白质结构.
- 较大的蛋白质或有限的样本大小需要提高光谱灵敏度.
- 质子检测 (1H) 提供了一个有前途的途径,以提高NMR的灵敏度.
研究的目的:
- 开发和演示实验方案,以在完全质子化蛋白质的固态NMR中增强质子检测.
- 使用这种方法来评估灵敏度增长和光谱分配能力.
- 评估较高磁场对灵敏度和分辨率的影响.
主要方法:
- 使用完全质子化,均标记13C,15N的蛋白质GB1.1.
- 采用了40 kHz和750 MHz的魔法角旋转 (MAS) 速率,使用1.6毫米的旋转器.
- 进行了3DNMR实验 (CANH,CONH,NCAH) 进行光谱分配.
主要成果:
- 在500MHz检测1H时获得3-4倍的灵敏度增强,而不是在500MHz直接检测13C和15N时.
- 在500 MHz和40 kHz的MAS观察到1ppm的质子线宽度 (500 +/- 150 Hz).
- 证明了高效的光谱赋值,蛋白质<1微摩尔,使脊柱和部分侧链赋值成为可能.
- 在750 MHz和40 kHz的MAS,质子线宽度提高到360 +/- 115 Hz.
- 观察到灵敏度和分辨率在磁场较高的情况下增加超过线性,为1H与15N检测产生14倍的灵敏度.
结论:
- 质子检测显著提高了对完全质子化蛋白质的固态NMR的灵敏度.
- 这种增强的灵敏度使得蛋白质的频谱分配更加有效,即使样本数量有限.
- 增加磁场强度进一步提高了灵敏度和分辨率,扩大了固态NMR对更大,更复杂的系统的适用性.
相关概念视频
Proton (¹H) NMR: Chemical Shift
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Absorption signals of all the protium nuclei in a...
Absorption signals of all the protium nuclei in a...
¹H NMR of Labile Protons: Temporal Resolution
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The –OH proton in alcohols typically appears in the range of δ 2 to 5 ppm but can vary depending on the specific...
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NMR Spectroscopy Of Amines
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¹H NMR of Labile Protons: Deuterium (²H) Substitution
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Double Resonance Techniques: Overview
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
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When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...

