Cuprous oxidase activity of yeast Fet3p and human ceruloplasmin: implication for function

FEBS Letters

Stoj, Christopher¹  Kosman, Daniel J¹ 

[1] Department of Biochemistry, School of Medicine and Biomedical Sciences, State University of New York, 140 Farber Hall, 3435 Main St., Buffalo, NY 14214, USA

关键词: Ferroxidase;    Ceruloplasmin;    Fet3p;    Copper homeostasis;    Copper toxicity;    Multicopper oxidase;    Saccharomyces cerevisiae;    MCO;    multicopper oxidase;    hCp;    human ceruloplasmin;    Hp;    hephaestin;    GPI;    glycosyl phosphatidylinositol;   

DOI  :  10.1016/S0014-5793(03)01218-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The Fet3 protein in Saccharomyces cerevisiae and mammalian ceruloplasmin are multicopper oxidases (MCO) that are required for iron homeostasis via their catalysis of the ferroxidase reaction, 4Fe²⁺+O₂+4H⁺→4Fe³⁺+2H₂O. The enzymes may play an essential role in copper homeostasis since they exhibit a strikingly similar kinetic activity towards Cu¹⁺ as substrate. In contrast, laccase, an MCO that exhibits weak activity towards Fe²⁺, exhibits a similarly weak activity towards Cu¹⁺. Kinetic analyses of the Fet3p reaction demonstrate that the ferroxidase and cuprous oxidase activities are due to the same electron transfer site on the enzyme. These two ferroxidases are fully competent kinetically to play a major role in maintaining the cuprous–cupric redox balance in aerobic organisms.

【 授权许可】

Unknown