Formation of N-(hexanoyl)ethanolamine, a novel
phosphatidylethanolamine adduct, during the oxidation of erythrocyte membrane
and low-density lipoprotein
Issue title: The Proceedings of the 3rd International
Conference on Food Factors (ICoFF 03)
Affiliations: Laboratory of Food and Biodynamics, Graduate School of
Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan | School of Humanities for Environmental Policy and
Technology, Himeji Institute of Technology, Himeji 670-0092, Japan
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.
