title: Formation of N-(hexanoyl)ethanolamine, a novel phosphatidylethanolamine adduct, during the oxidation of erythrocyte membrane and low-density lipoprotein.
abstract: The primary amino groups of biomolecules such as aminophospholipids, as well as proteins, are the potential targets of covalent modifications by lipid peroxidation products; however, little attention has been paid to the modification of aminophospholipids such as phosphatidylethanolamine (PE). The purpose of this study is to characterize the formation of a novel modified phospholipid, N-(hexanoyl)phosphatidylethanolamine (HEPE), in the reaction of PE with lipid hydroperoxides using mass spectrometric analyses. Upon reaction of egg PE with 13-hydroperoxyoctadecadienoic acid or other oxidized polyunsaturated fatty acids followed by phospholipase D-mediated hydrolysis, the formation of N-(hexanoyl)ethanolamine (HEEA), a head group of HEPE, was confirmed by isotope dilution liquid chromatography/tandem mass spectrometry. Moreover, increasing HEEA was detected in the hydrolysates of oxidized erythrocyte ghosts and low-density lipoprotein with their increasing lipid peroxidation levels. Collectively, these results suggest that the N-hexanoylated product of phospholipid, HEPE, can be generated during lipid peroxidation and may serve as one mechanism for the covalent modification of aminophospholipids in vivo.
authors.affiliation: Laboratory of Food and Biodynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Tsuji
authors.forename: Yoshichika
authors.initials: Y
authors.lastname: Kawai
authors.forename: Yoji
authors.initials: Y
authors.lastname: Kato
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Osawa
mesh_terms: D004910:Erythrocyte Membrane / Q000378:metabolism*; D004983:Ethanolamines / Q000737:chemistry*; D006801:Humans; D008054:Lipid Peroxides; D008077:Lipoproteins, LDL / Q000097:blood*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008563:Membrane Lipids / Q000097:blood; D010084:Oxidation-Reduction; D010714:Phosphatidylethanolamines / Q000737:chemistry*
chemical_list: D004983:Ethanolamines; D008054:Lipid Peroxides; D008077:Lipoproteins, LDL; D008563:Membrane Lipids; C499478:N-(hexanoyl)ethanolamine; D010714:Phosphatidylethanolamines