麻烦的反向交换在 MALDI 羽毛及其对/交换质谱分析的影响
Xianwen Lou1, Michel van Houtem2, René P M Lafleur1
1Department of Chemical Engineering and Chemistry, Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, The Netherlands.
Journal of mass spectrometry : JMS
|December 23, 2024
概括
矩阵辅助激光脱吸/电离 (MALDI) 在/交换质谱学 (HDX MS) 中可以导致显著的反向交换. 这个过程可能会通过扭曲同位素分布来影响超分子组合分析.
科学领域:
- 分析化学 分析化学
- 生物物理化学 生物物理化学
背景情况:
- /交换质谱 (HDX MS) 是研究蛋白质动态和相互作用的强大技术.
- 背部交换,标签的意外丢失,是HDX MS分析中的一个关键挑战.
- 矩阵辅助激光脱离/电离 (MALDI) 是一种在质谱学中常用的电离方法.
研究的目的:
- 在 HDX MS. MALDI 过程中调查回交的程度和机制.
- 评估MALDI诱导的反向交换对和超分子组合分析的影响.
主要方法:
- 在D2O中制备了一种-1,3,5-三胺 (BTA) 化合物和五种的脱样本.
- 样品使用MALDI质谱分析.
- 通过分析同位素分布来量化MALDI羽毛中的反向交换.
主要成果:
- 马尔迪工艺本身产生了显著的反向交换,特别是在反应性羽毛中.
- 侧链,末端组和骨干胺基的背面交换率各不相同,骨干胺基的交换速度较慢,取决于主要结构.
- 在测试的酸中观察到骨干胺中5%-15%的标签丢失.
- 马尔迪诱导的反向交换可以扭曲或合并超分子组合中的同位素分布,使EX1机制的解释变得复杂.
结论:
- 马尔迪电离可以在HDX MS.中引入显著程度的反向交换.
- 虽然通常可以用于标准分析,但这种反向交换对于超分子组合的HDX MS研究可能是有问题的,可能会掩盖关键的结构信息.
相关概念视频
00:48¹H NMR of Labile Protons: Deuterium (²H) Substitution
876
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.
876
01:20¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
1.0K
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...
1.0K
01:13¹H NMR: Complex Splitting
1.2K
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...
1.2K
01:20Inductively Coupled Plasma-Mass Spectrometry (ICP-MS): Interferences
382
Inductively coupled plasma–mass spectrometry (ICP–MS) is a highly selective and sensitive technique for accurate elemental analysis. Though the analysis of ICP–MS mass spectra is comparatively straightforward, it is affected by spectroscopic and non-spectroscopic interferences. Spectroscopic interferences arise when the plasma contains ionic species with an m/z value the same as the analyte ion. Spectroscopic interference can be categorized as isobaric, polyatomic ions, and...
382
01:21Mass Spectrometry: Complex Analysis
714
Mass spectrometry is an important technique for the identification of pure compounds. However, it has some limitations for the analysis of complex mixtures, often due to excessive fragmentation making the spectrum too complicated to decipher. Mass spectrometry can be combined with suitable separation methods in sequence, forming hyphenated methods, which are useful in the analysis of complex mixtures.
GC–MS is a powerful hyphenated method commonly used in forensics and environmental...
GC–MS is a powerful hyphenated method commonly used in forensics and environmental...
714
01:13Mass Spectrometry: Isotope Effect
1.9K
Most elements exist in nature as a mixture of isotopes. The isotopes differ in weight due to their respective number of neutrons. The molecular weight of a molecule is different depending on the specific isotope of its elements involved. As a result, the mass spectrum of the molecule exhibits peaks from the same fragment at multiple positions. The positions of these mass signals depend on the difference between the molecular mass. Furthermore, the intensity of these signals is dependent on the...
1.9K