Phospholipids with a choline head group are an abundant component of cellular membranes and are involved in many important biological functions. For studies on the cell biology and metabolism of these lipids traceable analogues where propargylcholine replaces the choline head group have proven useful. We present a novel method to analyze propargylcholine phospholipids by mass spectrometry. The routine employs 1-radyl-2-lyso-sn-glycero-3-phosphopropargylcholines as labeled lysophosphatidylcholine (LPC) precursors, which upon cellular conversion direct the traceable tag with superb specificity and efficiency to the primary target lipid class. Using azido-palmitate as a click-chemistry reporter we introduce a highly specific, sensitive and robust mass spectrometry detection procedure for the propargylcholine phospholipids. In a first study we apply the new technique to investigate choline phospholipid metabolism in brain endothelial cells. These experiments reveal differences in the metabolism of phosphatidylcholine and its pendant, ether phosphatidylcholine. The novel method described here opens a new, quantitative and detailed view on propargylcholine phospholipid metabolism and will greatly facilitate future studies on choline phospholipid metabolism.

中文翻译：

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直接输注质谱法检测炔丙胆碱磷脂的先进方法。


具有胆碱头基的磷脂是细胞膜的丰富成分，参与许多重要的生物功能。对于这些脂质的细胞生物学和代谢的研究，已证明用炔丙胆碱取代胆碱头基的可追溯类似物是有用的。我们提出了一种通过质谱分析炔丙基胆碱磷脂的新方法。该程序采用 1-radyl-2-lyso-sn-glycero-3-磷酸炔丙胆碱作为标记的溶血磷脂酰胆碱 (LPC) 前体，在细胞转化后将可追踪标签以极好的特异性和效率引导至主要目标脂质类别。使用叠氮基棕榈酸酯作为点击化学报告基因，我们引入了一种高度特异性、灵敏且稳健的炔丙基胆碱磷脂质谱检测程序。在第一项研究中，我们应用新技术来研究脑内皮细胞中的胆碱磷脂代谢。这些实验揭示了磷脂酰胆碱及其侧链醚磷脂酰胆碱代谢的差异。这里描述的新方法为炔丙基胆碱磷脂代谢开辟了新的、定量的和详细的观点，并将极大地促进未来对胆碱磷脂代谢的研究。