Marine invertebrate glutathione- S-transferases: purification, characterization and induction

Abstract

High glutathione- S-transferase (GST) activity was found in hepatopancreas and gill cytosol of the blue crab ( Callinectes sapidus) and the digestive gland cytosol of two marine gastropods ( Nassarius obsoletus and Cerithium floridanum). Purification of GST from crab hepatopancreas by Sephadex G-200, DEAE-Sephacel and chromofocusing resulted in the isolation of two isoenzymes with isoelectric points of 5·9 and 5·7 (GST 5·9 and GST 5·7). Antibodies were prepared to these two isoenzymes and the two forms cross-reacted immunologically. The two transferases had similar molecular weights, amino acid compositions, substrate specifities and kinetic parameters. Crab gill cytosol showed one isoenzyme which reacted with antibodies to GST 5·9 and GST 5·7. The major isoenzyme of N. obsoletus was a basic form while C. floridanum showed a homodimer acidic form. The gastropod GST forms did not react with antibodies to crab GST. The presence of the phenolic antioxidant, butylated hydroxytoluene, in the diet of blue crab or shrimp ( Penaeus aztecus) resulted in high hepatic GST activity.