Distinct pathways for zinc metabolism in the terrestrial slug Arion vulgaris.

In most organisms, the concentration of free Zn is controlled by metallothioneins (MTs). In contrast, no significant proportions of Zn are bound to MTs in the slug, Arion vulgaris. Instead, this species possesses cytoplasmic low-molecular-weight Zn (LMW Zn) binding compound that divert these metal ions into pathways uncoupled from MT metabolism.