相关实验视频
Updated: Jul 16, 2026

08:03
Study of Protein Dynamics via Neutron Spin Echo Spectroscopy
Published on: April 13, 2022
展开的蛋白质状态中的侧链动态:基于NMR的2H自旋放松研究delta131delta的delta131delta
Wing-Yiu Choy1, David Shortle, Lewis E Kay
1The Protein Engineering Network Center of Excellence and Department of Medical Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8.
Journal of the American Chemical Society
|February 13, 2003
概括
新的NMR实验使得在未折叠的蛋白质中详细研究侧链动态. 这揭示了非均的蛋白质结构,并提供了对残留物波动的见解,有助于无序蛋白质研究.
科学领域:
- 生物物理学的生物物理.
- 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:
- 无序蛋白质的结构和动态特性至关重要,但对研究具有挑战性.
- 由于光谱分辨率问题,以前的NMR方法对未折叠蛋白质侧链动态的详细特定位置分析有限.
研究的目的:
- 开发新的NMR实验,用于测量未折叠蛋白质含甲基残留物中的侧链动态.
- 将这种方法应用于无序的蛋白质片段,并分析得到的数据.
主要方法:
- 开发新的NMR脉冲方案,用于测量未折叠蛋白质的甲基组中的侧链动态.
- 记录放松数据作为一系列的 (1) H-(15) N光谱来克服分辨率限制.
- 应用于葡萄球菌核酶的无序蛋白质片段delta131delta.
主要成果:
- 观察到甲基对称轴顺序参数和骨干 (1) H-(15) N键向量之间的相关性.
- 模拟表明,这种相关性意味着在未折叠状态下具有非同等概率的结构集合.
- 提出了一种运动模型,用于估计Val和Thr残留的chi(1) 扭矩角度波动 (sigma(chi) ((1)).
结论:
- 现在可以使用NMR详细研究未折叠蛋白质的侧链动态.
- 未折叠的蛋白质组合很可能不具有同等概率,从而影响动态.
- 估计的sigma ((chi) ((1) 值在未折叠的蛋白质中大于折叠的蛋白质,像Val 104这样的特定残留物显示出独特的动态,可能是由于疏水性聚类.
相关概念视频
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...
¹H NMR of Labile Protons: Temporal Resolution
Protons bonded to heteroatoms such as nitrogen and oxygen exhibit a range of chemical shift values. This is due to the varying degree of hydrogen bonding between the proton and the heteroatom in other molecules. The extent of hydrogen bonding affects the electron density around the proton, thereby giving different chemical shift values for the protons in the proton NMR spectrum.
The –OH proton in alcohols typically appears in the range of δ 2 to 5 ppm but can vary depending on the specific...
The –OH proton in alcohols typically appears in the range of δ 2 to 5 ppm but can vary depending on the specific...
¹H NMR of Labile Protons: Deuterium (²H) Substitution
This lesson illustrates the role of deuterium substitution in simplifying the NMR spectrum of compounds comprising labile protons. One method employed is the use of deuterium. Amongst the three isotopes of hydrogen, deuterium (2H) has a nucleus composed of one proton and one neutron. When the D2O solvent is added to a pure dry ethanol solution, its labile proton is substituted with deuterium.
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.
¹³C NMR: ¹H–¹³C Decoupling
The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
Atomic Nuclei: Types of Nuclear Relaxation
Nuclear relaxation restores the equilibrium population imbalance and can occur via spin–lattice or spin–spin mechanisms, which are first-order exponential decay processes.
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers energy to a nearby...
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers energy to a nearby...

