(Copper, zinc)--thionein in pig liver.

The concentrations of zinc and/or copper in the hepatic metallothionein of young (1–11 days, and 8 week-old) pigs correlate with the concentration of whole liver zinc. In the livers of adult animals only thionein-bound zinc correlates with total zinc. Although thionein-bound copper correlates with total copper in the livers of developing pigs, it shows a higher degree of correlation with whole liver zinc.Hepatic (copper, zinc) -thioneins, from either the young or the adult pig, in which the Cu : Zn ratio is high, are denatured on columns of DE cellulose, or during preparative electrophoresis. Preparations in which the Cu : Zn ratio is lower are resolved by ion-exchange chromatography into three forms, all of which contain both cations, but in differing ratios. Electrophoresis of a (copper, zinc) thionein that contains the two cations in 1 : atomic ratio yields zinc-thionein as a single distinct molecular species.