Metallothionein Determination by Isocratic HPLC with Fluorescence Derivatization

Metallothionein (MT) is reported as having an intensive affinity to a number of heavy metal ions such as Zn²⁺ , Cd²⁺ , Cu²⁺ , and Hg²⁺ , which suggests a relation with zinc and copper homeostasis (1 ). The structural uniqueness of MT is expressed by its high cysteine content without intramolecular cystine bonding; 20 cysteins in 61 amino acids, and all the sulfuhydryl groups of cysteine residues coordinate to metal ions Fig. 1 ). The importance of MT in protection against oxidative stress (2 ) in addition to detoxification of heavy metals (1 ) is reviewed. In oxidative stress and heavy-metal toxicology studies, MT has been considered to be one of the important factors that should be monitored.