The relationship between the zinc status of pigs and the occurrence of copper- and Zn-binding proteins in liver.

1. A study has been made by gel filtration techniques of the soluble copper- and zinc-binding proteins in livers from pigs of different Zn status. 2. The distribution of both Cu and Zn between the three fractions isolated was greatly influenced by the Zn status of the animal. In livers from pigs given a Zn-supplemented diet the proportion of either Cu or Zn found in the fraction with a molecular weight of about 12 000 (fraction 3) was a direct function of the total liver concentration of the metal. In livers from pigs given a low-Zn diet, only small amounts of Cu or Zn were present in this fraction, regardless of liver Cu content. 3. These results suggest that Zn may be essential for the stabilization of the metal-binding protein in this fraction.