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Ceruloplasmin as low‐density lipoprotein oxidase: activation by ascorbate and dehydroascorbate
Author(s) -
Feichtenhofer Sabine,
Fabjan Judith S,
Abuja Peter M
Publication year - 2001
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(01)02623-0
Subject(s) - chemistry , low density lipoprotein , ceruloplasmin , dehydroascorbic acid , redox , biochemistry , oxidative phosphorylation , lipoprotein , ascorbic acid , lipid oxidation , antioxidant , inorganic chemistry , cholesterol , food science , vitamin c
The ability of ceruloplasmin (Cp) to oxidize low‐density lipoproteins (LDL) in the presence of water‐soluble antioxidants was investigated and a reaction mechanism proposed. Ascorbate strongly enhanced LDL oxidation, but only after its rapid consumption. Dehydroascorbate enhanced Cp‐mediated LDL oxidation even more strongly. Lipid‐soluble antioxidants and water‐soluble peroxides did not show noticeable activation. However, loading of LDL with lipid hydroperoxides increased the initial oxidation rate. We conclude that Cp mediates a localized redox cycle, where reduction of Cp‐Cu 2+ is effected by water‐soluble reductants and reoxidation by liposoluble hydroperoxides.