Removal and efflux of copper from Cu-metallothionein as Cu/tetrathiomolybdate complex in LEC rats.

Tetrathiomolybdate (TTM) removes copper (Cu) accumulating in a form bound to metallothionein (MT) in the liver of LEC rats (Long-Evans rats with a cinnamon-like coat color). The first step in the removal of Cu from Cu-MT has been shown to form a complex between MT and TTM through (MT)-S-Cu-S-(TTM) bridges (referred to as MT/TTM complex). Additional TTM was demonstrated to remove Cu from MT/TTM complex as the second step to form Cu/TTM complex by liberating MT. The Cu/TTM complex binds specifically to albumin in serum and to high molecular weight proteins in the absence of albumin, and is assumed to be a form of Cu for efflux by the treatment with TTM.