Linear ion-trap MSn with high-resolution MS reveals structural diversity of 1-O-acylceramide family in mouse epidermis.
J Lipid Res
; 58(4): 772-782, 2017 04.
Article
em En
| MEDLINE
| ID: mdl-28154204
ABSTRACT
1-O-acylceramide is a new class of epidermal cer-amide (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 140- to 300-O-acyl) and N-acyl chains (from 140- to 341-N-acyl) with 181-sphingosine as the major LCB were found for the entire family. Minor isomers consisting of 161-, 171-, 182-, and 191-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.
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1
Base de dados:
MEDLINE
Assunto principal:
Ceramidas
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Epiderme
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Lipídeos
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article