文章基本信息

标题：Linear ion-trap MSn with high-resolution MS reveals structural diversity of 1-O-acylceramide family in mouse epidermis
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作者：Meei-Hua Lin ; Jeffrey H. Miner ; John Turk 等
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：2017
卷号：58
期号：4
页码：772-782
DOI：10.1194/jlr.D071647
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：1-O-acylceramide is a new class of epidermal ceramide (Cer) found in humans and mice. Here, we report an ESI linear ion-trap (LIT) multiple-stage MS (MSⁿ) approach with high resolution toward structural characterization of this lipid family isolated from mice. Molecular species desorbed as the [M + H]⁺ ions were subjected to LIT MS² to yield predominately the [M + H − H₂O]⁺ ions, followed by MS³ to cleave the 1-O-acyl residue to yield the [M + H − H₂O − (1-O-FA)]⁺ ions. The structures of the N-acyl chain and long-chain base (LCB) of the molecule were determined by MS⁴ on [M + H − H₂O − (1-O-FA)]⁺ ions that yielded multiple sets of specific ions. Using this approach, isomers varied in the 1-O-acyl (from 14:0- to 30:0-O-acyl) and N-acyl chains (from 14:0- to 34:1-N-acyl) with 18:1-sphingosine as the major LCB were found for the entire family. Minor isomers consisting of 16:1-, 17:1-, 18:2-, and 19:1-sphingosine LCBs with odd fatty acyl chain or with monounsaturated N- or O-fatty acyl substituents were also identified. An estimation of more than 700 1-O-acylceramide species, largely isobaric isomers, are present, underscoring the complexity of this Cer family.
关键词：skin ceramide ; lipidomics ; multiple-stage tandem mass spectrometry ; electrospray ionization ; higher collision energy dissociation ; sphingolipid ; high-resolution mass spectrometry