Development of Charge Transfer Dissociation Mass Spectrometry (CTD-MS) of Oligosaccharides

在化学系化学测量和成像项目的支持下，西维吉尼亚大学的格伦·杰克逊教授和他的团队正在开发表征低聚糖的仪器，低聚糖是对生命系统至关重要的复杂糖分子。具体来说，Jackson博士正在评估和扩展质谱法作为确定这些复杂生物分子结构的手段的实用性。这项研究得益于与位于法国南特的法国国家农业研究所（INRA）的一个研究团队的合作和学生交流。正在开发的工具有助于回答有关生物分子的结构和功能的重要问题，包括但不限于低聚糖。例如，新的仪器可以解决糖是如何被消化的问题，食品级果胶的胶凝特性，以及生命系统中的细胞识别途径。该项目还提供了一种机制，通过在当地科学展览会上组织活动站来教育小学生。Jackson小组正在开发两个质谱仪，一个2D和一个3D离子阱，用于低聚糖的电荷转移解离（CTD）。最初的努力是通过在反应物离子束中加入额外的离子光学元件来提高碎片化效率。这种改性还可以减少反应时间，使CTD能够与复杂混合物的超高性能液相色谱分离相结合。仪器变量如试剂离子动能、通量和电子亲和（通过惰性气体的选择）；CTD反应时间；并对捕获参数（qz）进行了优化，以增强碎片行为。主要目的是阐明碎片化的一般规则，并确定增强低聚糖表征的最佳条件。利用分离得到的具有良好特征的低聚糖来阐明低聚糖性质对其破碎程度和性质的影响。预计影响糖苷和交叉环断裂机制的性质包括：聚糖序列、残基间的连接位置、分支点、电荷状态、内合离子和聚糖修饰，如酯化、胺化和磺化。进一步的研究探讨了CTD对其他含氧低聚物的功效，包括聚合物、聚乙二醇化药物、阴离子表面活性剂和寡核苷酸。这些综合研究表明了CTD相对于现有技术的优势和劣势，并有助于指导未来的高影响力应用研究。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professor Glen Jackson and his group at West Virginia University are developing instruments for the characterization of oligosaccharides - complex sugar molecules critical to living systems. Specifically, Dr. Jackson is assessing and expanding the usefulness of mass spectrometry as a means of determining the structure of these complex biomolecules. The research benefits from collaboration and student exchanges with a research team at the French National Institute for Agricultural Research (INRA) in Nantes, France. The tools being developed help answer important questions about the structure and function of biological molecules including, but not limited to, oligosaccharides. The new instruments can address, for example, questions about how sugars are digested, the gelling properties of food-grade pectins, and cell recognition pathways in living systems. The project is also providing a mechanism to educate elementary school students through organization of activity stations at local science fairs.The Jackson group is developing two mass spectrometers, a 2D and a 3D ion trap, for charge transfer dissociation (CTD) of oligosaccharides. Initial efforts seek to improve fragmentation efficiency by incorporating additional ion optics in the reactant ion beam. This modification may also reduce reaction times, enabling CTD to be coupled with ultra-high performance liquid chromatographic separations of complex mixtures. Instrument variables such as reagent ion kinetic energy, flux, and electron affinity (through the choice of noble gas); CTD reaction time; and the trapping parameter (qz) are optimized to enhance fragmentation behavior. Key aims are the elucidation of general rules for fragmentation and identification of the best conditions with which to augment oligosaccharide characterization. Isolated fractions of well-characterized oligosaccharides are used to elucidate the effect of oligosaccharide properties on the extent and nature of fragmentation. Properties expected to influence glycosidic and cross-ring fragmentation mechanisms include: glycan sequence, inter-residue linkage position, branching point, charge state, adducting ions, and glycan modifications such as esterification, amination and sulfation. Additional studies investigate the efficacy of CTD towards other oxygenated oligomers, including polymers, PEGylated drugs, anionic surfactants and oligonucleotides. These combined studies demonstrate the strengths and weaknesses of CTD relative to existing technologies and help guide future research towards high-impact applications.