Glutathione-S-transferase as a molecular biomarker of the state of marine organisms influenced by anthropogenic pressure

The activity of glutathione-S-transferase (GST), a key phase II enzyme catalyzing the biotrans-formation of organic electrophilic compounds, was studied in the bivalve Crenomytilus grayanus, the mysid shrimp Neomysis mirabilis, and the flounder Liopsetta pinnifasciata from Peter the Great Bay, Sea of Japan. GST activity was increased in fish and mollusks from polluted areas of the bay, compared to background areas. In mysid shrimps, pollution caused inhibition of the activity of this enzyme. The role of GST in adaptation processes of different species to the current level of pollution is discussed.