Multistage Mass Spectrometry of Phospholipids using Collision-Induced Dissociation (CID) and Metastable Atom-Activated Dissociation (MAD).
Multistage Mass Spectrometry of Phospholipids using Collision-Induced Dissociation (CID) and Metastable Atom-Activated Dissociation (MAD).
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DOI：
10.1016/j.ijms.2016.02.010
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发表时间：
2016-06-01
影响因子：
1.8
通讯作者：
Jackson GP
中科院分区：
文献类型：
--
作者：
Li P;Hoffmann WD;Jackson GP
我们在此展示了一种气相离子操作的方法，该方法提供了磷脂自由基阳离子的MS 3级CID光谱，该光谱几乎不依赖于原始的充电加合物离子。在质子化，钠化和钾化的POPC加合物的MS 2 He-MAD光谱中，不同的加合物诱导不同的初级裂解途径，并提供显着不同的光谱，如通常通过其他活化方法观察到的。采用氦亚稳原子活化解离（He-MAD）将1-棕榈酰-2-油酰磷脂酰胆碱（POPC）的偶电子加合离子（[M+H]+，[M+Na]+，[M+K]+）转化为自由基阳离子[POPC]+·，然后用低能碰撞诱导解离（CID）诱导POPC的酰基链沿着断裂.这种电荷远程碎裂通常无法通过偶电子前体离子的低能CID来实现。He-MAD和CID的组合提供了自由基诱导的光谱，其显示出非常大的相似性和仅微小的差异，因此克服了否则由原始加合物物种观察到的化学上的主要差异。偶数电子[POPC+H]+的碰撞活化需要比奇数电子[POPC]+·更高的CID振幅来实现碎片化-正如预期的那样-并且后者提供了受双键位置影响的酰基链内的碎片。
We herein demonstrate an approach to gas phase ion manipulation that provides MS3-level CID spectra of phospholipid radical cations that are almost independent of the original charging adduct ions. In the MS2 He-MAD spectra of the protonated, sodiated and potassiated adducts of POPC, the different adducts induce different primary fragmentation pathways and provide significantly different spectra, as is commonly observed by other activation methods. In separate experiments, the even-electron adduct ions ([M+H]+, [M+Na]+, [M+K]+) of 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) were first converted to radical cations [POPC]+• by using helium metastable atom-activated dissociation (He-MAD) to eject the charging adduct ions, then exposed to low-energy collision induced dissociation (CID) to induce extensive fragmentation along the acyl chains. Such charge-remote fragmentation is generally inaccessible through low-energy CID of the even-electron precursor ions. The combination of He-MAD and CID provides radical-induced spectra that show very major similarities and only minor differences, and therefore overcomes major differences in chemistry that are otherwise observed by the original adducting species. Collisional activation of even-electron [POPC+H]+ required higher CID amplitudes than odd-electron [POPC]+• to effect fragmentation—as expected—and the latter provided fragments within the acyl chains that were influenced by the double bond position.