Liquid chromatography/tandem mass spectrometry characterization of nitroso, nitrated and nitroxidized cardiolipin products

Advancing Target Identification of Nitrated Phospholipids in Biological Systems by HCD Specific Fragmentation Fingerprinting in Orbitrap Platforms

“…Our results showed that it was not the case when NO 2 -PLs were characterized by HCD-MS/MS. The absence of this typical fragmentation was recently observed for the characterization of nitrated cardiolipins (CLs) under HCD-MS/MS [13] In our study, an increase in the intensity yield of other product ions was obtained when the medium (25) and high (30) NCE ranges were applied. Some of these ions were also observed for the CID-MS/MS analysis of nitrated PCs and PEs, namely the ions formed by the combined loss of HNO 2 and the polar head group [10,12].…”

“…These results are in agreement with the previous results reported by Neves and co-authors [11] for nitrated PS derivatives where low m/z reporter ions, attributed to the carboxylate anions of the modified fatty acyl chains, were seen with a higher relative abundance in the HCD-MS/MS spectra acquired in the orbitrap instrument, while in the CID-MS/MS the product ions with higher m/z values, as the ones formed by the typical NL of HNO 2 , were the ones seen with a higher relative abundance in MS/MS spectra. Montero-Bullon and co-authors [13] also found that the product ions of nitrated fatty acyl arose as one of the most informative fragmentation pathways of nitrated CLs. These differences are due to the higher energy dissociations in HCD (<100 eV) than those used in the resonant-excitation CID (<2 eV) [37].…”

“…Lipidomics has been widely applied for the large-scale characterization of lipid profiles and quantification of individual lipid molecular species using either targeted or untargeted MS-based approaches that include shotgun methods and HPLC-MS based strategies. It has also been applied in the study of nitrated PLs by using CID-MS/MS [10,12] and HCD-MS/MS approaches [11,13]. A very recent work on the characterization of nitrated POPS has revealed differences in the fragmentation patterns and reporter ions typical of these modified lipids under both CID-and HCD-MS/MS conditions [11].…”

“…Molecules 2020, 25, 2120; doi:10.3390/molecules25092120 www.mdpi.com/journal/molecules and nitroxidized FAs [4][5][6] have been recognized as important endogenous signalling molecules [7][8][9]. On the other hand, nitrated PLs have only been reported recently in in vitro model systems and biological samples and structurally characterized by mass spectrometry (MS) approaches [10][11][12][13]. Nitrated PCs and nitrated PEs were detected in the cardiac mitochondria of diabetic rats and cardiomyocytes under starvation using liquid chromatography (LC) coupled to a linear ion trap mass spectrometer (LIT) and were characterized by low energy collision-induced dissociation (CID) tandem mass spectrometry (MS/MS) [10,12].…”

Formation of Oxidatively Modified Lipids as the Basis for a Cellular Epilipidome

“…Subsequent loss of nitrous acid (HNO 2 ) leads to nitro-alkenes, and substitution with water can form nitrohydroxy lipids ( 51 ). As with oxidation products resulting from free radical attack, the molecular rearrangements of nitro-lipids allow a wide variety of positional and stereochemical isomers to be formed, for example on phosphatidylserine ( 57 ), cardiolipin ( 58 ), phosphatidylcholine, and phosphatidylethanolamine ( 59 ). Nitrated fatty acids have been detected in human plasma, suggesting that they are biologically relevant lipid products ( 60 ).…”