Toxicology 2
Protection against toxicants
Metallothioneins
- Multigene family consisting of 4 classes
- Low molecular weight metal binding protein
- Binds to metallic cations due to its high cysteine content
- Cysteine sulfhydryl groups bind Zn2+, Cd2+, Hg2+ and other heavy metallic cations
- Each metallothionein molecule can bind up to 7 Zn2+, Cd2+ ions
- Neutralise harmful influences of exposure to toxic metals e.g Cd and Hg