TOXICOLOGICAL
SIGNIFICANCE OF METALLOTHIONEINS
Göknur
AKTAY*°, Tülin SÖYLEMEZOÐLU*
*°Ankara Üniversitesi, Adli Tip
Enistitüsü, Dikimevi, 06100, Ankara, TÜRKIYE
Summary:
Metallothionin, containing thiol groups is a metal-binding
low molecular weight protein. It has an important role
not only in the metabolism of the essential metals such
as zinc and copper which are necessary for growth and
improvement of organism, but also the detoxification of
harmful heavy metals such as cadmium, mercury and iron.
The studies carried on the physiological, pharmacological
and toxicological effects of this protein indicated that
its biological significance depends on the prevention
of the cellular damage caused by free radicals. On the
other hand, copper and iron departed from metallothionein
may cause oxidative stress by indicating the Fenton reaction.
The contradiction in these results shows that some more
detailed studies such as biological-synthesis and degradation
of metallothionein and some biochemical parameters such
as lipid peroxidation must be done to explain the biological
function of metallothionein. In this review, the toxicological
importance of metallothionein, a metalloprotein, in the
aspect of environmental pollution, antioxidant properties
and the relationship with the metals is discussed.
Key words:
Metalloproteins, metallothioneins, oxidative stress, lipid
peroxidation, trace elements, heavy metals.
