Campbell J Larry, Baba Takashi
SCIEX, 71 Four Valley Drive, Concord, Ontario L4K 4V8, Canada.
Anal Chem. 2015 Jun 2;87(11):5837-45. doi: 10.1021/acs.analchem.5b01460. Epub 2015 May 20.
Although lipids are critical components of many cellular assemblies and biological pathways, accurate descriptions of their molecular structures remain difficult to obtain. Many benchtop characterization methods require arduous and time-consuming procedures, and multiple assays are required whenever a new structural feature is probed. Here, we describe a new mass-spectrometry-based workflow for enhanced structural lipidomics that, in a single experiment, can yield almost complete structural information for a given glycerophospholipid (GPL) species. This includes the lipid's sum (Brutto) composition from the accurate mass measured for the intact lipid ion and the characteristic headgroup fragment, the regioisomer composition from fragment ions unique to the sn-1 and sn-2 positions, and the positions of carbon-carbon double bonds in the lipid acyl chains. Here, lipid ions are fragmented using electron impact excitation of ions from organics (EIEIO)--a technique where the singly charged lipid ions are irradiated by an electron beam, producing diagnostic product ions. We have evaluated this methodology on various lipid standards, as well as on a biological extract, to demonstrate this new method's utility.
尽管脂质是许多细胞组件和生物途径的关键组成部分，但要准确描述其分子结构仍然困难重重。许多台式表征方法需要繁琐且耗时的程序，每当探测新的结构特征时都需要进行多次测定。在此，我们描述了一种基于质谱的增强型结构脂质组学新工作流程，该流程在单次实验中就能为给定的甘油磷脂（GPL）种类提供几乎完整的结构信息。这包括从完整脂质离子和特征性头部基团碎片的精确质量测得的脂质总（粗）组成、来自sn-1和sn-2位置特有的碎片离子的区域异构体组成，以及脂质酰基链中碳 - 碳双键的位置。在这里，脂质离子通过有机离子的电子碰撞激发（EIEIO）进行裂解——这是一种通过电子束照射单电荷脂质离子来产生诊断性产物离子的技术。我们已在各种脂质标准品以及生物提取物上评估了该方法，以证明这种新方法的实用性。
