DIFFERENTIATION OF ALPHA- VS BETA- ASPARTIC ACID USING ETD

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 我们最近成功地表明ECD可以轻松区分肽和蛋白质中的α-和β-天冬氨酸残基，这提出了一个明显的问题：相同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检测。 因此，在ASMS 2005之后，与普渡大学的Scott McLuckey教授的小组开始了合作。 特定的标记肽样品被送到普渡大学，光谱被返回，这表明这种技术确实也适用于ETD。 该手稿发表在《美国质谱学会杂志》上。 该数据在与Paul Goodley合作的Agilent ETD离子阱上重现。 最终结果是，虽然ETD确实能够区分天冬氨酸和异天冬氨酸，但与ECD不同，它具有竞争性的“质子转移”或“电荷剥离”通道，这会降低离子丰度。 这可能取决于反应参数，并且希望ETD可以像在模型肽上那样被“调谐”以改善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.