Zemski Berry Karin A, Turner William W, VanNieuwenhze Michael S, Murphy Robert C
Department of Pharmacology, University of Colorado Denver, Aurora, CO 80045, USA.
Eur J Mass Spectrom (Chichester). 2010;16(3):463-70. doi: 10.1255/ejms.1083.
Recently, a derivative of PE, namely the 4-(dimethylamino)benzoic acid derivative has been developed with various isotope labeled variants that provided a universal precursor ion scan for diacyl, ether and plasmalogen PE lipids that can not be accomplished otherwise. This derivative was further investigated as a means to facilitate characterization of various oxidized phosphatidylethanolamine lipids by collision activation. Phospholipids derived from RAW 264.7 cells were treated with a free radical generating system to generate a complex mixture of oxidized and non-oxidized lipids that were separated by reversed-phase high-performance liquid chromatography and detected using a precursors of m/z 191 scan for the d(0)-DMABA-labeled control sample and a precursor of m/z 197 scan for the d(6)-DMABA-labeled oxidized sample. Collisional activation of the corresponding M - H ions permitted the identification of several chain shortened omega-aldehydes, as well as direct oxygen addition products including isoprostane PE and monohydroxy PE oxidized phospholipids that were not easily detected without the use of the DMABA derivatives. The stable isotope labeled derivatives permitted assessment of relative quantitative changes in oxidized lipids based upon ion abundance.
最近，已开发出一种PE衍生物，即4-(二甲基氨基)苯甲酸衍生物，它有各种同位素标记变体，可对二酰基、醚和缩醛磷脂酰乙醇胺脂质进行通用的前体离子扫描，否则无法实现。进一步研究了该衍生物，作为通过碰撞活化促进各种氧化磷脂酰乙醇胺脂质表征的一种手段。用自由基产生系统处理源自RAW 264.7细胞的磷脂，以生成氧化和未氧化脂质的复杂混合物，通过反相高效液相色谱分离，并使用m/z 191扫描的前体检测d(0)-DMABA标记的对照样品，使用m/z 197扫描的前体检测d(6)-DMABA标记的氧化样品。对相应的M - H离子进行碰撞活化，可鉴定出几种链缩短的ω-醛，以及直接加氧产物，包括异前列腺素PE和单羟基PE氧化磷脂，若不使用DMABA衍生物则不易检测到。稳定同位素标记的衍生物允许根据离子丰度评估氧化脂质的相对定量变化。
