Thiol‐linked peroxidase activity of human ceruloplasmin

FEBS Letters

Park, Seon Young¹  Kim, In Gyu¹  Yum, Jung Joo²  Kim, Kug Chan¹ 

[1] Department of Radiation Biology, Environment Radiation Research Group, Korea Atomic Energy Research Institute, P.O. Box 105, Yusong, Taejon 305-600, South Korea;Department of Biology, Chongju University, Chongju 360-764, South Korea

关键词: Ceruloplasmin;    Metal-catalyzed oxidation system;    Ascorbate;    Dithiothreitol;    Reduced glutathione;    Peroxidase;   

DOI  :  10.1016/S0014-5793(98)00817-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Human ceruloplasmin exhibited different antioxidant effects according to the electron donors in a metal-catalyzed oxidation system. Purified ceruloplasmin did not play a significant role in the protection of DNA strand breaks in the ascorbate/Fe³⁺/O₂ system. However, when ascorbates were replaced with a thiol-reducing equivalent such as dithiothreitol, DNA strand breaks were significantly prevented by the same amount of ceruloplasmin. Ceruloplasmin did not catalyze the decomposition of H₂O₂ in the absence of reduced glutathione. On the contrary, ceruloplasmin showed a potent peroxidase ability to destroy H₂O₂ in the presence of reduced glutathione. In conclusion, the removal of H₂O₂ by human ceruloplasmin is not simply stoichiometric but thiol-dependent.

【 授权许可】

Unknown