RELATIONSHIP BETWEEN ZINC STATUS OF PIGS AND OCCURRENCE OF COPPER-BINDING AND ZN-BINDING PROTEINS IN LIVER

The soluble Cu- and Zn-binding proteins in livers from pigs of different Zn status was studied by gel filtration techniques. The distribution of both Cu and Zn between the 3 fractions isolated was 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. Zn may be essential for the stabilization of the metal-binding protein in this fraction.