Photodissociation for Ion Trap Mass Spectrometry

化学部的分析和表面化学计划将支持德克萨斯大学奥斯汀分校的Jennifer Broadbelt教授的研究计划。Broadbelt教授在质谱领域的研究计划将涉及在四极离子阱质谱仪中使用红外和紫外激光进行离子的光解离，沿着新颖的化学衍生方法以增加化学选择性或提高分子的吸收率。 在用红外或紫外光子照射离子时，离子吸收导致键断裂的能量，导致形成诊断碎片离子。 这些片段化模式提供了分子的“指纹”，从而允许肽和其他生物学相关分子的可靠鉴定。 光子的吸收对于这种分析方法的成功至关重要，因此可以通过连接不同的化学基团（称为“发色团”）来调节分子的吸收率，这些化学基团可以增强光子的吸收。该研究的目的是通过一系列衍生化策略添加发色团来增加目标分析物的光子吸收效率。 Broadbelt教授和她的学生将在生物分子上添加化学基团，以促进气相中的光活化反应，例如在光活化后以位点特异性，可预测的方式选择性切割多肽骨架。 拟议工作对整个社会的潜在好处包括培训和教育未来的科学家，特别是在生物质谱领域，开发用于生物分子结构表征的创新激光方法，以及实施新的离子活化策略，预计这些策略在许多领域的质谱分析中非常重要，从蛋白质组学到理解生物大分子相互作用的复杂性。

The Analytical and Surface Chemistry program in the Division of Chemistry will support the research program of Prof. Jennifer Broadbelt of the University of Texas at Austin. Prof. Broadbelt's research program in the area of mass spectrometry will involve the use of both infrared and ultraviolet lasers for photo dissociation of ions in a quadrupole ion trap mass spectrometer, along with novel chemical derivatization methods to add chemical selectivity or enhance absorptivities of molecules. Upon irradiation of ions with infrared or ultraviolet photons, the ions absorb energy that leads to bond cleavages, resulting in formation of diagnostic fragment ions. These fragmentation patterns provide a "fingerprint" of the molecules, thus allowing confident identification of peptides and other biologically relevant molecules. The absorption of photons is essential for the success of this analytical method, and thus the absorptivity of molecules can be modulated by attaching different chemical groups, termed "chromophores", that enhance the absorption of photons. The objective of the study is to increase the photon absorption efficiencies of targeted analytes by appending chromophores via an array of derivatization strategies. Prof. Broadbelt and her students will append chemical groups to biomolecules that promote photoactivated reactions in the gas phase, such as the selective cleavage of polypeptide backbones in a site-specific, predictable manner upon photoactivation. The potential benefits of the proposed work to society at large include the training and education of future scientists, especially in the area of biological mass spectrometry, the development of innovative laser-based methods for structural characterization of biological molecules, and implementation of new ion activation strategies that are expected to be important in mass spectrometric analysis in many areas, ranging from proteomics to understanding the complexities of interactions of biological macromolecules.