Electrospray ionization tandem mass spectrometry of glycerophosphoethanolamine plasmalogen phospholipids

• Published in: Journal of the American Society for Mass Spectrometry 2004-10, Vol.15 (10), p.1499-1508
• Main Authors: Zemski Berry, Karin A., Murphy, Robert C.
• Format: Article
• Language: English
• Subjects: Analytical, structural and metabolic biochemistry; Biological and medical sciences; Diagnostic software; Diagnostic systems; Electrospraying; Esterification; Fundamental and applied biological sciences. Psychology; Glycerolipids, phospholipids; Humans; Ionization; Ions; Lipids; Mass spectrometry; Molecular Structure; Neutrophils - chemistry; Other biological molecules; Phosphatidylethanolamines - analysis; Phosphatidylethanolamines - chemistry; Phospholipids; Plasmalogens - analysis; Plasmalogens - chemistry; Scientific imaging; Spectrometry, Mass, Electrospray Ionization; Spectroscopy
• ISSN: 1044-0305; 1879-1123
• DOI: 10.1016/j.jasms.2004.07.009

Collision-induced dissociation (CID) of the [M + H] + of glycerophospholipids typically results in abundant fragment ions that are related to the polar head group or loss of the polar head group. An exception to this general rule occurs for glycerophosphoethanolamines (GPEtn), which are a class of phospholipids that can have an acyl, 1-O-alkyl, or 1-O-alk-1′-enyl group as a substituent at the sn-1 position. The CID of the [M + H] + of diacyl-GPEtn typically results in the expected loss of the phosphoethanolamine head group (141 Da). Therefore, constant neutral loss of 141 Da has been used as a diagnostic tool for the determination of GPEtn species in complex lipid mixtures. One disadvantage in using constant neutral loss of 141 Da in order to determine GPEtn content in lipid mixtures is that plasmalogen GPEtn does not undergo neutral loss of phosphoethanolamine to the same extent as diacyl-GPEtn. The current studies have used positive ion mode electrospray tandem mass spectrometry to study the collision-induced dissociation of various GPEtn plasmalogens present in the phospholipid membranes of human neutrophils. The CID of the [M + H] + of plasmalogen GPEtn resulted in two prominent fragment ions; one that was characteristic of the sn-1 position and one that was characteristic of the sn-2 position. These two ions were used to detect specific molecular species of GPEtn containing esterified arachidonate (precursors of m/z 361) present in the human neutrophil.