Abstract
Metallothionein (MT) is often a major copper-binding protein in the liver, particularly of copper-loaded animals. This review describes the isolation of hepatic copper-MT, its physicochemical properties, biosynthesis and intracellular distribution, and possible routes for its degradation and secretion. There is increasing evidence that MT plays an important role in the cellular detoxification of copper, although an involvement in the uptake, storage and transfer of copper has also been proposed. These roles are discussed.