The oxidation of α‐tocopherol in human low‐density lipoprotein by the simultaneous generation of superoxide and nitric oxide

FEBS Letters

Moncada, Salvador¹  Wilson, Michael T.²  Darley-Usmar, Victor M.¹  Hogg, Neil² 

[1] The Wellcome Research Laboratories, Beckenham, Kent, BR3 3BS, UK;Department of Chemistry and Biological Chemistry, University of Essex, Colchester, Essex, C04 3SQ, UK

关键词: Nitric oxide;    Superoxide;    Peroxynitrite;    Low-density lipoprotein;    Atherosclerosis;    LDL;    low density lipoprotein;    SNAP;    S-nitroso-n-acetylpenicillamine;    13-HPODE;    [9Z;    11E;    13(S)]-13-hydroperoxyoctadecadien-1-oic acid;    DTPA;    diethylenetriamine penta acetic acid;    PBS;    phosphate-buffered saline;    SOD;    superoxide dismutase;    TBARS;    thiobarbituric acid reactive substances;    MDA;    malondialdehyde;   

DOI  :  10.1016/0014-5793(93)81790-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Peroxynitrite is the product of the reaction between nitric oxide and superoxide. It is an oxidant which can also decompose to form the hydroxyl radical and nitrogen dioxide. In this report we show that a powerful oxidant with reactivity similar to that of the hydroxyl radical is formed from the generation of superoxide from xanthine oxidase and nitric oxide from S-nitroso-n-acetylpenicillamine (SNAP). Simultaneous generation of these two radicals by either xanthine oxidase/SNAP or the sydnonimine SIN-1 in the presence of low-density lipoprotein (LDL) results in the depletion of α-tocopherol and formation of its oxidised product α-tocopheroquinone. The mechanism of oxidation required both the formation of nitric oxide and superoxide. In contrast to the promotion of LDL oxidation by transition metals the oxidation of LDL by SIN-1 was not sensitive to the addition of exogenous lipid hydroperoxide.

【 授权许可】

Unknown