Covalent modifications of aminophospholipids by 4-hydroxynonenal.
Lipid oxidation is implicated in a wide range of pathophysiological disorders, which leads to reactive compounds such as aldehydes. Among them 4-hydroxynonenal (4-HNE) reacts strongly with the NH2 groups of amino acids and forms mainly Michael adducts and minor Schiff-base adducts. Such reactions occur also with compounds containing thiol groups. No data are available describing 4-HNE interactions with amino-phospholipids. To investigate such a possibility, 4-HNE was incubated with either phosphatidylethanolamine (PE) or phosphatidylserine (PS) in an aqueous-organic biphasic system and the resulting products were identified by liquid chromatography-mass spectrometry (LC-MS). Our study points out the potential capacity of 4-HNE to react with phospholipids containing amino groups and particularly PE. The main resulting compounds found were a Michael adduct plus a minor Schiff base adduct, which was partly cyclized as a pyrrole derivative via a loss of water. Its stabilization as a pyrrole derivative allows to differentiate 4-HNE from the other aldehydes generated via lipid oxidation (e.g., malondialdehyde, 2-nonenal) that lack the 4-hydroxyl group. Their formation seems not to be affected when the pH varies from 6.5 to 8.5. Surprisingly, PS reacted poorly producing only a small amount of Michael adduct, the Schiff-base adduct being nondetectable. We conclude that such adducts, if they are formed in cell membranes, could alter the phospholipase-dependent cell signaling.
Guichardant
M
M
INSERM U352, Biochimie & Pharmacologie, INSA-Lyon, France. guichard@insa-lyon.fr
Taibi-Tronche
P
P
Fay
L B
LB
Lagarde
M
M
D000447:Aldehydes / Q000378:metabolism*; D000588:Amines / Q000378:metabolism*; D001792:Blood Platelets / Q000378:metabolism*; D002853:Chromatography, Liquid; D002855:Chromatography, Thin Layer; D006801:Humans; D015227:Lipid Peroxidation; D013058:Mass Spectrometry; D015394:Molecular Structure; D010714:Phosphatidylethanolamines / Q000378:metabolism; D010718:Phosphatidylserines / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism*; D012545:Schiff Bases / Q000032:analysis
D000447:Aldehydes; D000588:Amines; D010714:Phosphatidylethanolamines; D010718:Phosphatidylserines; D010743:Phospholipids; D012545:Schiff Bases; C027576:4-hydroxy-2-nonenal