title: MALDI-TOF MS to monitor the kinetics of phospholipase A2-digestion of oxidized phospholipids.
abstract: Free fatty acids (FFA) are released through phospholipase A2 (PLA2), which cleaves the fatty acyl residue at the sn-2 position of phospholipids (PL). During inflammatory diseases, reactive oxygen species (such as HOCl) lead to the formation of oxidatively modified PL (e.g., chlorohydrin generation). It is still widely unknown to which extent the oxidation of PL influences their digestibility by PLA2. Additionally, investigations on the impact of the position of the unsaturated fatty acyl residue (sn-1 versus sn-2 position) and modifications of the headgroup (for instance phosphatidylcholine (PC) versus phosphatidylethanolamine (PE)) are also lacking. Therefore, the aim of this study is the investigation of these aspects using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry to elucidate the PL/lysophospholipid (LPL) ratios as measures of the PLA2 digestibility. We will show that oxidative modifications of PL by HOCl have a considerable impact on the PLA2 digestibility, i.e., oxidation of the unsaturated fatty acyl residues leads to a reduced digestibility of both PC and PE. Besides, it will be shown that MALDI MS is a convenient and reliable tool to investigate the related changes.
authors.affiliation: University of Leipzig, Medical Faculty, Institute of Medical Physics and Biophysics, Härtelstr. 16-18, D-04107 Leipzig, Germany. Electronic address: jenny.schroeter@medizin.uni-leipzig.de.
authors.forename: Jenny
authors.initials: J
authors.lastname: Schröter
authors.affiliation: University of Leipzig, Medical Faculty, Institute of Medical Physics and Biophysics, Härtelstr. 16-18, D-04107 Leipzig, Germany. Electronic address: rosmarie.suess@medizin.uni-leipzig.de.
authors.forename: Rosmarie
authors.initials: R
authors.lastname: Süß
authors.affiliation: University of Leipzig, Medical Faculty, Institute of Medical Physics and Biophysics, Härtelstr. 16-18, D-04107 Leipzig, Germany. Electronic address: juergen.schiller@medizin.uni-leipzig.de.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schiller
mesh_terms: D007700:Kinetics; D010084:Oxidation-Reduction; D010713:Phosphatidylcholines / Q000737:chemistry; D010714:Phosphatidylethanolamines / Q000737:chemistry; D054467:Phospholipases A2 / Q000737:chemistry*; D010743:Phospholipids / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010743:Phospholipids; C483858:phosphatidylethanolamine; D054467:Phospholipases A2
keywords: Hypochlorous acid; MALDI-TOF MS; Phospholipase A(2); Phospholipid; Phospholipid chlorohydrin