Turnover of the Copper and Protein Moieties of Ceruloplasmin

Abstract

APPROXIMATELY 95 per cent of the plasma copper in both mouse and man is normally present as a moiety of ceruloplasmin1. Ceruloplasmin, an α-globulin containing 0.34 per cent copper, exhibits oxidase activity in vitro with a variety of substrates2 and reversibly releases at least half its copper upon reduction3. Whether ceruloplasmin plays a part in the transport of copper or acts as an oxidase in vivo, however, is not known. In the work reported here, the function of ceruloplasmin in mice was investigated by determining the rate of exchange of its copper moiety. © 1960 Nature Publishing Group.