Tyrosine: an inhibitor of LDL oxidation and endothelial cell cytotoxicity initiated by superoxide/nitric oxide radicals

FEBS Letters

Hermann, Marcela³  Mühl, Adolf¹  Held, Irmtraud⁴  Gmeiner, Bernhard⁴  Kapiotis, Stylianos² 

[1] Department of Pediatrics, University of Vienna, Vienna, Austria;Clinical Institute of Medical and Chemical Laboratory Diagnostics, University of Vienna, Vienna, Austria;Institute of Molecular Genetics, University of Vienna, Vienna, Austria;Institute of Medical Chemistry, University of Vienna, Währingerstr. 10, Vienna A-1090, Austria

关键词: LDL oxidation;    Superoxide;    Nitric oxide;    Antioxidant;    Tyrosine;    SIN-1;   

DOI  :  10.1016/S0014-5793(97)00513-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Tyrosyl radicals can catalyze LDL oxidation. In addition to their LDL oxidizing ability, superoxide (O₂ ^·−)/nitric oxide (NO^·) generate phenoxyl radicals when reacting with tyrosine. Therefore we tested if tyrosine can act as a pro-oxidant in O₂ ^·−/NO^·-initiated LDL oxidation. When LDL was exposed to O₂ ^·−/NO^·, tyrosine exerted a strong inhibitory effect on O₂ ^·−/NO^·-initiated LDL oxidation as measured by TBARS formation and alteration in electrophoretic mobility of LDL. Tyrosine was also able to protect human endothelial cells from the cytotoxic effect of O₂ ^·−/NO^·. Because O₂ ^·−/NO^· can occur in vivo, the results may indicate that serum-free tyrosine could act as an efficacious physiological antioxidant in case of O₂ ^·−/NO^·-initiated LDL oxidation and endothelial cell cytotoxicity.

【 授权许可】

Unknown