Rapid and selective identification of molecular species in phosphatidylcholine and sphingomyelin by conditional neutral loss scanning and MS3
Rapid and selective identification of molecular species in phosphatidylcholine and sphingomyelin by conditional neutral loss scanning and MS3
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DOI：
10.1002/rcm.1737
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发表时间：
2004-01-01
影响因子：
2
通讯作者：
Taguchi, R
中科院分区：
文献类型：
--
作者：
Houjou, T;Yamatani, K;Taguchi, R
本文报道了含胆碱磷脂（Ch）如磷脂酰胆碱（PC）和鞘磷脂（SM）的分子种类分析。中性丢失扫描应用于选择性检测这些脂质使用四极杆线性离子阱质谱仪。通过使用甲酸铵作为洗脱缓冲液，在负离子模式下PC和SM均被检测为[M+HCOO]（-）离子。在碰撞活化时，[M+HCOO]（-）加合物离子经历HCO 2的容易消除，以产生离子，该离子又容易经历碰撞诱导解离（CID）以消除CH 3，以产生[M-CH 3]（-）离子。通过选择合适的条件进行扫描60 Da（HCO 2 + CH 3）的中性损失，SM物种从PC中分离出来。此外，通过选择该[M-CH 3]（-）离子作为前体离子，PC物种的脂肪酰基链的身份可以有效地通过MS 3实验获得。此外，通过对从SM分子特异性获得的[M-CH 3]（-）的MS 3分析，还可以有效地获得鞘氨醇或鞘氨醇衍生物及其N-酰基种类的鉴定。通过条件中性损失扫描对PC和SM进行系统分析，随后通过MS 3进行分析，使用线性离子阱质谱仪在负离子模式下进行分析，似乎是一种非常有效和灵敏的方法。此外，在相对低的碰撞能量下，正离子模式的MS/MS也可有效地从其lysoPC相关片段中识别单个分子PC种类的位置特异性。本文仅涉及单个分子种类的定性鉴定，相关的定量研究正在进行中。版权所有（C）2004约翰威利父子有限公司。
Analyses of molecular species of phospholipids containing choline (Ch), such as phosphatidylcholine (PC) and sphingomyelin (SM), are reported. Neutral loss scanning was applied for the selective detection of these lipids using a quadrupole-linear ion trap mass spectrometer. By using ammonium formate as an elution buffer, both PC and SM were detected as [M+HCOO](-) ions in the negative ion mode. Upon collisional activation, the [M+HCOO](-) adduct ions underwent facile elimination of HCO2, to yield an ion which, in turn, readily underwent collisional-induced dissociation (CID) to eliminate CH3 to yield an [M-CH3](-) ion. By selecting the proper conditions for scanning for neutral loss of 60 Da (HCO2+CH3) SM species were identified separately from PCs. Further, by selection of this [M-CH3](-) ion as the precursor ion, the identities of the fatty acyl chains of PC species can be effectively obtained by MS3 experiments. Furthermore, by the MS3 analyses of [M-CH3](-) specifically obtained from SM molecules, identification of sphingosine or sphinganine derivatives and their N-acyl species can also be effectively obtained. This systematic analysis of PCs and SMs by conditional neutral loss scanning, with subsequent analyses by MS3, using a linear ion trap mass spectrometer in the negative ion mode, appears to be a very effective and sensitive method. Further, MS/MS in the positive ion mode at relatively low collision energy was also effective for the identification of positional specificities in individual molecular PC species from their lysoPC-related fragments. The present paper deals only with qualitative identification of individual molecular species, and the related quantitative studies are now underway. Copyright (C) 2004 John Wiley Sons, Ltd.