在生理温度下的结构生物学中的光谱直角旋转标签
Markus Teucher1, Svetlana Kucher1,2, M Hadi Timachi1
1Faculty of Chemistry and Biochemistry, Ruhr University of Bochum, Bochum 44801, Germany.
The journal of physical chemistry. B
|July 25, 2023
概括
这项研究使用直角旋转标签,如加多和氧化物与电子磁共振 (EPR) 光谱,以揭示生理温度下的生物分子动力学和相互作用,增强结构生物学见解.
科学领域:
- 生物物理学的生物物理.
- 结构生物学 结构生物学
- 频谱学是一种光谱学方法.
背景情况:
- 电子偏磁共振 (EPR) 光谱是使用脉冲二极光谱 (PDS) 在低温下测量生物大分子中的距离的关键.
- 在EPR研究中,直角旋转标签增强了每个样本的数据采集.
- 目前的EPR方法通常仅限于冷温度,限制了在生理条件下的动态过程的研究.
研究的目的:
- 在使用EPR的生理温度下研究生物分子动力学和相互作用.
- 为了利用加多和氧化物旋转标签的独特特性,以增强信息检索.
- 探索侧链和水动力学,以及在本地条件下生物分子的短距离距离.
主要方法:
- 使用X波段的连续波 (cw) EPR来分析侧链动态.
- 在X频段采用Overhauser动态核极化 (ODNP) 来研究地表水的动态.
- 在高场应用cw EPR以确定短距离距离.
- 整合直角旋转标签 (加多和氧化物) 用于多模式分析.
主要成果:
- 证明了使用 cw EPR 在 X 波段与特定旋转标签研究侧链动态的能力.
- 通过ODNP在X频段成功监测了地表水动态.
- 使用高场cw EPR量化短距离距离.
- 在生理条件下,从直角标签中展示了信息内容的增加.
结论:
- 正角旋转标签与多种EPR技术相结合,为生理温度下的生物分子行为提供了前所未有的洞察力.
- 这些方法揭示了在冷温度下以前无法获得的分子相互作用和动态平衡.
- 提出的方法显著推进生物分子在生物学相关状态的研究.
相关概念视频
Atomic Nuclei: Nuclear Spin State Population Distribution
1.0K
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
1.0K
NMR Spectroscopy: Spin–Spin Coupling
1.5K
The spin state of an NMR-active nucleus can have a slight effect on its immediate electronic environment. This effect propagates through the intervening bonds and affects the electronic environments of NMR-active nuclei up to three bonds away; occasionally, even farther. This phenomenon is called spin–spin coupling or J-coupling. Coupling interactions are mutual and result in small changes in the absorption frequencies of both nuclei involved. While nuclei of the same element are involved...
1.5K
¹H NMR: Interpreting Distorted and Overlapping Signals
1.1K
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
1.1K
Atomic Nuclei: Nuclear Spin State Overview
1.0K
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of...
1.0K
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
1.1K
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.
1.1K
2D NMR: Overview of Homonuclear Correlation Techniques
239
Homonuclear correlation spectroscopy (COSY) is a powerful technique used in Nuclear Magnetic Resonance (NMR) spectroscopy to study the correlations between nuclei of the same type within a molecule. It provides information about scalar couplings between adjacent nuclei, which helps determine connectivity and structural information. There are several COSY variants, each with its unique strengths and experimental parameters.
COSY90 is the standard two-dimensional (2D) COSY experiment that...
COSY90 is the standard two-dimensional (2D) COSY experiment that...
239


