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.