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Cuprous oxidase activity of yeast Fet3p and human ceruloplasmin: implication for function
Author(s) -
Stoj Christopher,
Kosman Daniel J
Publication year - 2003
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(03)01218-3
Subject(s) - ceruloplasmin , multicopper oxidase , chemistry , enzyme , substrate (aquarium) , redox , oxidase test , catalysis , metalloprotein , yeast , biochemistry , laccase , saccharomyces cerevisiae , copper , inorganic chemistry , biology , organic chemistry , ecology
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, 4Fe 2+ +O 2 +4H + →4Fe 3+ +2H 2 O. The enzymes may play an essential role in copper homeostasis since they exhibit a strikingly similar kinetic activity towards Cu 1+ as substrate. In contrast, laccase, an MCO that exhibits weak activity towards Fe 2+ , exhibits a similarly weak activity towards Cu 1+ . 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.