DIFFERENTIATION OF ALPHA- VS BETA- ASPARTIC ACID USING ETD

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 我们最近成功地证明了ECD可以很容易地区分多肽和蛋白质中的α-和β-天冬氨酸残基，这提出了一个明显的问题，即同样的方法是否可以用于电子转移解离(ETD)。但是，资源中不存在ETD指令插入。因此，在ASMS 2005年之后，在普渡与Scott McLuckey教授的团队开始了一项合作。特定的标记多肽的样本被送往普渡大学，并返回光谱，这表明这项技术确实适用于ETD。这篇手稿发表在《美国质谱学学会杂志》上。 这一数据是在安捷伦ETD离子陷阱上与保罗·古德利合作复制的。最终的结果是，虽然ETD确实能区分天冬氨酸和异天冬氨酸，但与ECD不同的是，它有一个竞争的“质子转移”或“电荷剥离”通道，降低了离子丰度。这可能取决于反应参数，并希望ETD可以像在模型多肽上一样进行“调谐”，以改进对这些诊断离子的检测。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Our recent success in showing that ECD can easily differentiate alpha- and beta- aspartic acid residues in peptides and proteins raised the obvious question as to whether or not the same methods could be used with Electron Transfer Dissociation (ETD). However, ETD instrumentation does not exist at the resource. Thus, following ASMS 2005, a collaboration was started with Prof. Scott McLuckey's group in Purdue. Samples of specific, labeled peptides were sent to Purdue, and spectra were returned which shows that this technique does indeed work with ETD as well. The manuscript was published in the Journal of the American Society for Mass Spectrometry. This data was reproduced on the Agilent ETD ion trap in collaboration with Paul Goodley. The net result was that, while ETD does work to distinguish aspartic and isoaspartic acids, unlike ECD, it has a competing "proton transfer" or "charge stripping" channel which reduces ion abundance. This may be dependent on reaction parameters, and it is hoped that ETD can be "tuned-in" as it was on the model peptides to improve detection of these diagnostic ions.