Department of Chemistry, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 10084, China.
National Engineering Research Center for the Emergency Drug, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
Anal Chem. 2022 Jan 18;94(2):820-828. doi: 10.1021/acs.analchem.1c03494. Epub 2021 Dec 21.
Phosphatidylethanolamines (PEs), ether-PEs, and phosphatidylserines (PSs) are glycerophospholipids harboring a primary amino group in their headgroups. They are key components of mammalian cell membranes and play pivotal roles in cell signaling and apoptosis. In this study, a liquid chromatography-mass spectrometry (LC-MS) workflow for deep profiling of PEs, ether-PEs, and PSs has been developed by integrating two orthogonal derivatizations: (1) derivatization of the primary amino group by 4-trimethylammoniumbutyryl--hydroxysuccinimide (TMAB-NHS) for enhanced LC separation and MS detection and (2) the Paternò-Büchi (PB) reaction for carbon-carbon double bond (C═C) derivatization and localization. Significant improvement of the limit of identification down to the C═C location has been achieved for the standards of PSs (3 nM) and ether-PEs (20 nM). This workflow facilitates an identification of more than 200 molecular species of aminophospholipids in the porcine brain, two times more than those identified without TMAB-NHS derivatization. Importantly, we discovered that the -10 isomers in C16:1 and C18:1 of aminophospholipids showed elevated contribution among other isomers, which correlated well with an increased transcription of the corresponding desaturase (FADS2) in the human breast cancer cell line (MDA-MB-231) relative to that in the normal cell line (HMEC). The abovementioned data suggest that lipid reprograming via forming different C═C location isomers might be an alternative mechanism in cancer cells.
磷脂酰乙醇胺（PEs）、醚-PEs 和磷脂酰丝氨酸（PSs）是甘油磷脂，其头部基团中含有一个伯氨基。它们是哺乳动物细胞膜的关键组成部分，在细胞信号转导和细胞凋亡中发挥关键作用。在这项研究中，通过整合两种正交衍生化方法，开发了一种用于深入分析 PEs、醚-PEs 和 PSs 的液相色谱-质谱（LC-MS）工作流程：（1）通过 4-三甲基铵丁酰基-羟基琥珀酰亚胺（TMAB-NHS）衍生化伯氨基，以增强 LC 分离和 MS 检测；（2）Paternò-Büchi（PB）反应衍生化和定位碳-碳双键（C═C）。PSs（3 nM）和醚-PEs（20 nM）的标准物的鉴定限显著提高，达到 C═C 位置。该工作流程有助于在猪脑中鉴定出 200 多种氨基磷脂的分子种类，是未经 TMAB-NHS 衍生化鉴定的两倍。重要的是，我们发现 C16:1 和 C18:1 的氨基磷脂中的-10 异构体与其他异构体相比表现出更高的贡献，这与在人类乳腺癌细胞系（MDA-MB-231）中相应去饱和酶（FADS2）的转录增加相对应，而在正常细胞系（HMEC）中则没有。上述数据表明，通过形成不同 C═C 位置异构体进行脂质重编程可能是癌细胞的另一种机制。
