Abstract
Metallothionein belongs to the family of metalloproteins, which are widely distributed in animal kingdoms, similar types of proteins have been described in bacteria, plants and fungi. These are low molecular weight (6-10 kDa) cysteine-rich proteins that do not require any aromatics.
About 30% of its weight is molecular cysteine, which requires the specific properties of metallothionein. Thanks to sulfhydryl groups, metallothionein can bind metal ions, 7 divalent ions or 12 monovalent ions.