Bulleigh Kellis, Howard Angela, Do Trang, Wu Qun, Anbalagan Victor, Stipdonk Michael Van
Department of Chemistry, Wichita State University, Wichita, KS 67260-0051, USA.
Rapid Commun Mass Spectrom. 2006;20(2):227-32. doi: 10.1002/rcm.2299.
In this study we used an isotope label, generated in situ, to investigate intramolecular proton migration or scrambling during formation of b(2)+17+Li products by collision-induced dissociation (CID) of Li(+)-cationized tripeptides. To generate the isotope label, we used a McLafferty-type rearrangement of N-terminally acetylated, C-terminal peptide tert-butyl esters in which all amide positions were exchanged with deuterium. Using a set of small, model peptides, we show that intramolecular proton scrambling occurs during CID, particularly amongst adjacent sites along a peptide backbone, on the time scales employed for low-energy collisional activation in an ion-trap mass spectrometer.
在本研究中，我们使用原位生成的同位素标记，来研究通过Li⁺阳离子化三肽的碰撞诱导解离（CID）形成b(2)+17+Li产物过程中的分子内质子迁移或重排。为了生成同位素标记，我们使用了N端乙酰化、C端肽叔丁酯的麦克拉弗蒂型重排，其中所有酰胺位置都被氘交换。使用一组小的模型肽，我们表明在离子阱质谱仪中用于低能碰撞活化的时间尺度上，CID过程中会发生分子内质子重排，特别是在肽主链上相邻位点之间。
