Review on Methods for Determination of Metallothioneins in Aquatic Organisms

Abstract

One aspect of environmental degradation in coastal areas is pollution from toxic metals, which are persistent and are bioaccumulated by marine organisms, with serious public health implications. A conventional monitoring system of environmental metal pollution includes measuring the level of selected metals in the whole organism or in respective organs. However, measuring only the metal content in particular organs does not give information about its effect at the subcellular level. Therefore, the evaluation of biochemical biomarker metallothionein may be useful in assessing metal exposure and the prediction of potential detrimental effects induced by metal contamination. There are some methods for the determination of metallothioneins including spectrophotometric method, electrochemical methods, chromatography, saturation-based methods, immunological methods, electrophoresis, and RT-PCR. In this paper, different methods are discussed briefly and the comparison between them will be presented.

Metallothionein as Potential Biomarker of Cadmium Exposure in Persian Sturgeon (Acipenser persicus)

“…Metallothioneins (MTs), first described by Margoshes and Vallee (1957), are small (6-7 kDa) cytosolic proteins involved in metal homeostasis and detoxification processes that contain about 60 amino acids (none of which aromatic) and a high content of cysteine residues (30% of total residues) [7,8]. It binds 7-10 equivalent metal ions per mole of proteins [9].…”

Evaluation of metallothionein content in giant mudskipper Periophthalmodon schlosseri collected from west coast of Peninsular Malaysia to assess environmental metal pollution

“…They are promising biomarkers for metal-specific stress in fish [10][11][12] and their synthesis is one of the best known biochemical responses to metal exposure. MTs are involved in the regulation of the essential metals copper and zinc and in the detoxification of non-essential metals [13], antioxidant activity [14,15] and radical scavenging [16] and helps in metal ion homeostasis in a cell [17]. The exposure of aquatic organisms to excess essential and non-essential metals induces MT expression in different species and tissues.…”

Determination of trace metallothioneins at nanogram levels with Eosin Y by resonance light scattering method

“…Over the past 10 years, several analytical methods for the determination of MTs have been reported [11], such as metal saturation assays [12], atomic absorption spectroscopy [13], and so on [14]. These methods are primarily indirect and based on the content of coordinated metal ions in MT molecules or based on the high content of sulphydryl groups, and suffer from many deficiencies, including insufficient specificity and sensitivity.…”