EFFECTS OF CHLORAMINE-T AND CuSO4 ON ENZYME ACTIVITY OF GLUCOSE 6-PHOSPHATE DEHYDROGENASE FROM RAINBOW TROUT (ONCORHYNCHUS MYKISS) ERYTHROCYTES IN VITRO AND IN VIVO

Traditional treatments of parasitic and bacterial diseases are based on chemotherapeutic compounds such as chloramine-T and CuSO4. Although many compounds are used in fish treatments, their undesirable effects are not known. In this study, glucose 6-phosphate dehydrogenase (G6PD) was purified from rainbow trout (Oncorhynchus mykiss) erythrocytes by hemolysate preparation, ammonium sulfate precipitation and 2', 5'-ADP Sepharose 4B affinity gel chromatography in a single day. The enzyme, with a specific activity of 14.51 EU/mg protein, was purified 906.8-fold with a yield of 70.38%. To check the purity of the enzyme, SDS polyacrylamide gel electrophoresis was performed, which showed a single band. The effects of chloramine-T and copper sulfate (CuSO4) on the G6PD were investigated in vitro. Chloramine-T and CuSO4 had inhibitory effects on the enzyme. I50 values of the chemotherapeutic compounds were determined by plotting percent activity and Ki values, and types of inhibition were determined for each compound by means of Lineweaver-Burk graphs. In vivo studies showed that G6PD in rainbow trout erythrocytes was significantly inhibited by CuSO4 in one hour but not inhibited by chloramine-T.