Oxidation of Human Low Density Lipoprotein Initiated by Copper(II)Chloride
Human low density lipoprotein (LDL) is a complex of a glycoprotein (apo B), free and esterified cholesterol, phospholipids, triglycerides and lipid soluble vitamins. It has been shown that oxidative modification of LDL mediated by free radical reactions renders LDL recognizable by the scavenger receptors of macrophages, cytotoxic towards fibroblasts and chemotactic towards monocytes.1,4 These and other properties of oxidized LDL might play an important role in atherogenesis. We have shown that oxidized LDL contains a great variety of aldehydes, such as 4-hydroxynonenal (HNE), derived from the oxidative breakdown of the polyunsaturated fatty acids. Moreover, the apo B of oxidized LDL exhibits a strong fluorescence at 360 nm excitation and 430 nm emission, which we attributed to covalent binding of HNE.5,6 Traces of metal ions, such as copper or iron, are most probably involved in the initiation of oxidation reactions in LDL. The aim of this investigation was to study the capacity of bivalent copper ions to initiate lipid peroxidation in LDL.
KeywordsCopper Concentration High Copper Concentration Initiate Lipid Peroxidation Lipid Soluble Vitamin Lower Copper Concentration
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