在大型蛋白质中的甲基组的全面和经济有效的NMR光谱学
Renee Otten1, Byron Chu, Karla D Krewulak
1Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
Journal of the American Chemical Society
|February 13, 2010
概括
这项研究引入了一种具有成本效益的NMR方法,用于在蛋白质中分配甲基,增强结构和动态研究. 该技术使用同位素标记来实现高灵敏度和分辨率,从而能够对更大的蛋白质系统进行详细分析.
科学领域:
- 生物化学 生物化学
- 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:
- 核磁共振 (NMR) 光谱对于蛋白质分析至关重要.
- 在蛋白质中分配甲基共振是具有挑战性的,但对于理解结构和动态至关重要.
- 目前的NMR方法通常在较大的蛋白质的灵敏度和分辨率上扎.
研究的目的:
- 开发一种敏感和高分辨率的NMR方法,用于蛋白质中的甲基共振赋值.
- 为了使蛋白质中含有甲基的氨基酸 (氨酸,氨酸,氨酸,氨酸,异氨酸) 的综合分析.
- 将NMR能力扩展到更大的蛋白质系统.
主要方法:
- 使用[{1}H,{1}C]-D-葡萄糖和~100%的D{2}O的细菌表达,以实现甲基组的经济有效的同位素丰富.
- 采用一个标签方案,通过消毒的侧链促进磁化转移.
- 选择了CHD(2) 甲基同位素,以提高检测灵敏度.
主要成果:
- 在甲基共振任务中实现了高灵敏度和出色的分辨率.
- 在34kDa的FepB蛋白序列中成功地分配了85% (164分之195) 的甲基 - - 具体和立体特定.
- 证明了该方法对更大的蛋白质的适用性,扩大了NMR的覆盖范围.
结论:
- 开发的NMR方法显著推进了蛋白质中的甲基共振赋值.
- 这种方法提供了一种具有成本效益和效率的方法来研究蛋白质结构,动态和相互作用.
- 该技术扩大了NMR应用的范围,包括更大的蛋白质复合体中的所有含甲基氨基酸.
相关概念视频
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Organic molecules primarily contain carbon and hydrogen atoms. While all the hydrogen isotopes are NMR-active, protium or hydrogen-1 is the most abundant. It has a significant energy separation between its nuclear spin states due to its large gyromagnetic ratio. As per Boltzmann's distribution, an increase in the energy separation implies a greater excess population of nuclei available for excitation, resulting in a strong NMR absorption signal.
Absorption signals of all the protium nuclei in a...
Absorption signals of all the protium nuclei in a...
Applications Of NMR In Biology
Nuclear magnetic resonance (NMR) spectroscopy is a very valuable analytical technique for researchers. It has been used for more than 50 years as an analytical tool. F. Bloch and E. Purcell formulated NMR in 1946 and won the 1952 Nobel Prize in Physics for their work. Biological macromolecules such as proteins, nucleic acids, lipids, and organic molecules including pharmaceutical compounds, can be studied using this versatile tool that exploits the magnetic properties of certain nuclei.
The...
The...
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A proteome is the entire set of proteins that a cell type produces. We can study proteomes using the knowledge of genomes because genes code for mRNAs, and the mRNAs encode proteins. Although mRNA analysis is a step in the right direction, not all mRNAs are translated into proteins.
Proteomics is the study of proteomes' function. It involves the large-scale systematic study of the proteome to denote the protein complement expressed by a genome. Scientist Mark Wilkins coined the term proteomics...
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¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
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...
¹H NMR Signal Integration: Overview
The intensity of a signal, which can be represented by the area under the peak, depends on the number of protons contributing to that signal. The area under each peak is shown as a vertical line called an integral, with the integral value listed under it, as seen in the proton NMR spectrum of benzyl acetate. Each integral value is divided by the smallest integral value to obtain the ratio of the number of protons producing each signal. The ratio reveals the relative number of protons and not...
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...


