Abstract
Nitrated lipids have been detected in vitro and in vivo, usually associated with a protective effect. While nitrated fatty acids have been widely studied, few studies reported the nitration and nitroxidation of the phospholipid classes phosphatidylcholine, and phosphatidylethanolamine. However, no information regarding nitrated and nitroxidized phosphatidylserine can be found in the literature. This work aims to identify and characterize the nitrated and nitroxidized derivatives of 1-palmitoyl-2-oleoyl-sn-3-glycero-phosphoserine (POPS), obtained after incubation with nitronium tetrafluoroborate, by liquid chromatography (LC) coupled to mass spectrometry (MS) and tandem MS (MS/MS). Several nitrated and nitroxidized products were identified, namely, nitro, nitroso, nitronitroso, and dinitro derivatives, as well as some nitroxidized species such as nitrosohydroxy, nitrohydroxy, and nitrohydroperoxy. The fragmentation pathways identified were structure-dependent and included the loss of HNO and HNO2 for nitroso and nitro derivatives, respectively. Combined losses of PS polar head group plus HNO or HNO2 and carboxylate anions of modified fatty acyl chain were also observed. The nitrated POPS also showed antiradical potential, demonstrated by the ability to scavenge the ABTS●+ and DPPH● radicals. Overall, this in vitro model of nitration based on LC-MS/MS provided additional insights into the nitrated and nitroxidized derivatives of PS and their fragmentation fingerprinting. This information is a valuable tool for targeted analysis of these modified PS in complex biological samples, to further explore the new clues on the antioxidant potential of nitrated POPS.
Highlights
Phosphatidylserine (PS) is a key phospholipid of the inner leaflet of the cell membranes, and it participates in several signaling and biological processes, namely targeting and function of intracellular signaling proteins [1,2,3]
The nitration of POPS was induced in a mimetic system of nitration by incubation with nitronium tetrafluoroborate (NO2 BF4 )
The reaction occurred in hydrophobic environments, mimicking the nitration that occurs in biological membranes [24], where reactive nitrogen species (RNS) diffuse and accumulate in the phospholipid bilayers [25,26,27]
Summary
Phosphatidylserine (PS) is a key phospholipid of the inner leaflet of the cell membranes, and it participates in several signaling and biological processes, namely targeting and function of intracellular signaling proteins [1,2,3]. Several studies identified and quantified nitrated fatty acids in biological systems, based on advanced mass spectrometry strategies, allowing to pinpoint nitrated fatty acids as important signaling molecules in health and disease [12,13,14]. Nitrated and nitroxidized derivatives of PCs and PEs were identified in vivo, namely in cardiac mitochondria isolated from the heart of an animal model of type 1 diabetes mellitus [15], and in vitro, in cardiomyoblast H9c2 cells under starvation conditions [16]. Recently, it was reported the potential of nitrated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
