通过同位素模式识别对蛋白质进行NMR分配
Uluk Rasulov1, Harrison K Wang2,3, Thibault Viennet4
1School of Chemistry, University of Southampton, University Road, Southampton SO17 1BJ, UK.
Science advances
|September 4, 2024
概括
这项研究引入了一种新的机器学习方法,用于在蛋白质核磁共振 (NMR) 光谱中更快地识别氨基酸信号. 该方法使用HNCA光谱快速分配蛋白质骨干,大大减少了结构生物学中的手工劳动.
科学领域:
- 结构生物学 结构生物学
- 生物物理学的生物物理.
- 计算化学的计算化学
背景情况:
- 蛋白质NMR光谱中的序列分配传统上依赖于人工,劳动密集的三重共振实验.
- 现有的软件和启发式工具有助于这一过程,但并不能消除所需的手工工作.
- 机器学习方法受到阻碍,因为需要大规模的训练数据集,包括所有物理细微差别和仪器工件.
研究的目的:
- 开发一种用于蛋白质NMR光谱中氨基酸信号识别的自动化和高效方法.
- 克服手动赋值和NMR机器学习中的大型复杂训练数据库的局限性.
- 为了实际应用,将一种新的计算方法与现有的行业标准软件集成在一起.
主要方法:
- 采用多基解构来存储数百万个模拟的三维NMR光谱.
- 在神经网络的训练过程中实现了仪器工件的飞行生成.
- 整合了前后信息的概率方法,并与CcpNmr软件框架集成.
主要成果:
- 开发的神经网络,处理HNCA光谱的 [1H, 13C] 切片,解释不同的CA信号形状.
- 神经网络输出一个氨基酸概率表,使得快速分配.
- 成功地分配了常见蛋白质 (GB1,MBP和INMT) 的骨干,仅使用HNCA光谱与初级序列信息相结合.
结论:
- 拟议的方法在蛋白质NMR中自动化氨基酸信号识别方面取得了重大进展.
- 这种方法大大减少了蛋白质骨干分配所需的时间和手工工作.
- 与CcpNmr的整合和高效的数据处理为结构生物学更广泛采用铺平了道路.
相关概念视频
¹H NMR: Pople Notation
1.7K
The Pople nomenclature system classifies spin systems based on the difference between their chemical shifts. Coupled spins are denoted by capital letters with subscripts indicating the number of equivalent nuclei. When the coupled nuclei have well-separated chemical shifts, they are assigned letters that are far apart in the alphabet, such as A and X. When the difference in chemical shifts is small, coupled nuclei are named using adjacent letters of the alphabet (AB, MN, or XY).
A proton...
A proton...
1.7K
¹³C NMR: ¹H–¹³C Decoupling
1.1K
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...
1.1K
Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule
1.2K
In the AX proton spin system, proton A can sense the two spin states of a coupled proton X, resulting in a doublet NMR signal with two peaks of equal (1:1) intensity. When proton A is coupled to two equivalent protons (AX2 spin system), the spin states of each X can be aligned with or against the external field, creating three possible scenarios. This results in a 1:2:1 triplet signal, where the central peak corresponds to the chemical shift of A and is twice as large or intense as the...
1.2K
Other Nuclides: 31P, 19F, 15N NMR
372
Many organic, inorganic, and biological molecules contain spin-half nuclei such as nitrogen-15, fluorine-19, and phosphorus-31. As a result, NMR studies of these nuclei have found extensive applications in chemical and biological research.
While fluorine-19 and phosphorous-31 have high natural abundances (100%) and positive gyromagnetic ratios, nitrogen-15 has a low natural abundance and a negative gyromagnetic ratio. However, nitrogen-15 is still preferred over nitrogen-14 (which has a...
While fluorine-19 and phosphorous-31 have high natural abundances (100%) and positive gyromagnetic ratios, nitrogen-15 has a low natural abundance and a negative gyromagnetic ratio. However, nitrogen-15 is still preferred over nitrogen-14 (which has a...
372
¹H NMR: Complex Splitting
1.3K
A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
1.3K
¹H NMR: Interpreting Distorted and Overlapping Signals
1.0K
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...
1.0K


