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Updated: Aug 14, 2026

Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development
Published on: April 15, 2013
The action of defined oxygen-centred free radicals on human low-density lipoprotein
S Bedwell1, R T Dean, W Jessup
1Department of Biology and Biochemistry, Brunel University, Uxbridge, Middlesex, U.K.
Abstract:
The effects of defined oxygen-centred free radicals on human low-density lipoprotein (LDL) structure and receptor affinity are discussed in relation to the mechanisms of cell-mediated oxidative modification of LDL. Both hydroxyl (OH.) and hydroperoxyl (HO2.) radicals caused depletion of endogenous alpha-tocopherol and formation of hydroperoxides. Superoxide (O2-.) radicals produced only very limited oxidation, but could potentiate oxidation stimulated by the addition of Cu2+. All these radicals enhanced the net negative charge of intact LDL and induced fragmentation of apolipoprotein B-100 (apo B). OH. also caused cross-linking of apo B. Radical attack decreased the affinity of LDL for the fibroblast apo B/E receptor, but did not enhance its endocytosis by mouse macrophages.
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