STUDIES ON ISOENZYMES OF GLUTATHIONE-S-TRANSFERASE IN THE DIGESTIVE GLAND OF MYTILUS-GALLOPROVINCIALIS WITH EXPOSURE TO POLLUTION

The possible utility of glutathione S-transferase isoenzymes in affini ty purified extracts of digestive gland from Mytilus galloprovincialis as indicators of exposure to organic pollution has been assessed by f ast protein liquid chromatography (FPLC) using a Mono-e ion exchange c olumn. Four main peaks of protein (isoenzymes 1-4) were detected in th ese chromatographic studies all of which displayed detectable catalyti c activity with 1-chloro-2,4-dinitrobenzene and glutathione as substra tes. The bulk of the activity with these substrates was associated wit h isoenzyme 1. The specific activity of cytosolic extracts from six si tes in Venice Lagoon and the Adriatic Sea (UNESCO-MURST Venice Lagoon Ecosystem Project) decreased slightly with increasing tissue levels of chemical contaminants (hydrocarbons, PCBs and organochlorines). FPLC of affinity purified extracts from three of these sites was used to as sess the possible variation in the levels of individual isoenzymes rel ative to pollution status. No difference was observed in the levels of these isoenzymes.