Dynamics of molecules and ions in the gas phase

气相中分子和离子的动力学

• 批准号: 194328-2006
• 负责人: Thachuk, Mark
• 金额: $ 2.94万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=392458
• 关键词: Dynamics; molecules; ions; gas; phase

The proposal involves projects that study the way ions move in the gas phase, and how the dynamics of this motion can be used to gain information about the structure of an ion, or to manipulate it in space. One major theme examines ions formed from protein complexes.  Experiments have shown that these complexes, in the gas phase, break up into pieces that have unusual charge distributions.  Specifically, the charges do not spread symmetrically among the pieces, as one would expect. The interesting question is, "Why does this happen?". The prevailing mechanism suggests that some proteins in the complex begin to unfold during the break up, and this causes the charge distributions to become asymmetric.  Our goal is to simulate these processes using computers running molecular dynamics codes, in an attempt to understand this mechanism in detail, and to control it.  One important part of this mechanism is the transfer of protons between different parts of the ion.  In the gas phase, the way protons move can be very different than in solution.  However, understanding proton transfer is very important for mass spectrometrists, who currently are using these gas phase species to sequence amino acids, and thus identify the proteins that exist in a cell or other biological sample. A second major theme is concerned with separating ions with different shapes.  The idea is to develop methods that will preferentially separate ions with non-spherical shapes from those that are spherical.  Such a technique would be very powerful for aerosol and atmospheric scientists, who analyze and study the reactions of chemicals in the environment.  Along the same lines, we would like to develop a method to align ions in the gas phase, to aid experiments that probe the reactivity and behaviour of gas phase species.

该提案涉及研究离子在气相中移动方式的项目，以及该运动的动力学如何用于获取有关离子结构或在太空中操纵其结构的信息。由蛋白质复合物形成的一个主要主题检查离子。实验表明，在气相中，这些复合物分解为具有异常电荷分布的碎片。具体而言，正如人们所期望的那样，这些费用不会对称地传播。有趣的问题是：“这为什么会发生？”。现行的机制表明，复合物中的某些蛋白质在分解过程中开始展开，这会导致电荷分布变得不对称。我们的目标是使用运行分子动力学代码的计算机模拟这些过程，以详细理解该机制并控制它。该机制的一个重要部分是质子在离子的不同部分之间的转移。在气相中，质子移动的方式可能与溶液中的方式有​​很大不同。但是，了解质子转移对于质谱学家目前正在使用这些气相物种来对氨基酸进行测序非常重要，从而确定了细胞或其他生物学样品中存在的蛋白质。第二个主要主题是用不同形状分离离子。这个想法是开发将具有非球形形状与球形的方法优先分离的方法。对于气雾剂和大气科学家来说，这种技术将非常有力，他们分析和研究化学物质在环境中的反应。按照相同的线路，我们想开发一种在气相中对齐离子的方法，以帮助探测气相物种的反应性和行为的实验。