Abstract
Low-molecular-weight metal-binding proteins have been implicated in the intracellular metabolism of copper, zinc, and cadmium. In this study, the major soluble copper-binding protein in the liver cytosol of 8-day-old chicks has been isolated. The copper-protein complex was detectable in the livers of control chicks but was absent in the livers of copper-deficient chicks. If the deficient chicks were injected with a single injection of CuSO4, the copper-protein complex appeared in the liver within two h. The copper-protein complex appeared to reach a maximum concentration in twenty h and had a half life of approximately thirty h. Purification of the copper-protein complex was accomplished by gel filtration (Sephadex G-75) and ion exchange (Sephadex DEAE-A25) chromatography. When 100 ug of the protein was placed on a sodium dodecyl sulfate polyacrylamide gel, only one protein band appeared. The molecular weight determined by SDS electrophoresis was 8,300 and the value estimated by gel filtration was 10,500. The purified copper protein contained 0.60% copper. Assuming a molecular weight of 8,300- 10,500, the protein contained 1.0-1.3 atoms of copper per molecule of protein. The copper protein contained 12.4% cysteine, 8.7% serine, and 10.4% glutamic acid, suggesting it was not metallothionein.
Balthrop, James Edgar (1981). Isolation and partial characterization of the major soluble copper-binding protein in chick liver. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -648498.