期刊
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
卷 33, 期 4, 页码 714-721出版社
AMER CHEMICAL SOC
DOI: 10.1021/jasms.2c00011
关键词
tandem mass spectrometry; radical-directed dissociation; lipidomics; methyl branching; cyclopropane
资金
- National Key R&D Program of China [2018YFA0800903]
- National Natural Science Foundation of China [22074075]
A radical-directed dissociation (RDD) approach was developed for characterizing intrachain modifications within phosphoethanolamines (PEs) in bacterial membranes. This method can generate fragment patterns to locate intrachain modifications and identify the fatty acyl chain composition of PEs.
Intrachain modifications of membrane glycerophos-pholipids (GPLs) due to formation of the carbon-carbon double bond (C=C), cyclopropane ring, and methyl branching are crucial for bacterial membrane homeostasis. Conventional collision-induced dissociation (CID) of even-electron ions of GPL favors charge-directed fragmentation channels, and thus little structurally informative fragments can be detected for locating intrachain modifications. In this study, we report a radical-directed dissociation (RDD) approach for characterization of the intrachain modifications within phosphoethanolamines (PEs), a major lipid component in bacterial membrane. In this method, a radical precursor that can produce benzyl or pyridine methyl radical upon low-energy CID at high efficiency is conjugated onto the amine group of PEs. The carbon-centered radical ions subsequently initiate RDD along the fatty acyl chain, producing fragment patterns key to the assignment and localization of intrachain modifications including C=C, cyclopropane rings, and methyl branching. Besides intrachain fragmentation, RDD on the glycerol backbone produces fatty acyl loss as radicals, allowing one to identify the fatty acyl chain composition of PE. Moreover, RDD of lyso-PEs produces radical losses for distinguishing the sn-isomers. The above RDD approach has been incorporated onto a liquid chromatography-mass spectrometry workflow and applied for the analysis of lipid extracts from Escherichia coli and Bacillus subtilis.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据