Effects of some metal ions on rainbow trout erythrocytes glutathione S-transferase enzyme: an in vitro study

Glutathione S-transferase enzyme (GST) (EC 2.5.1.18) was purified from rainbow trout erythrocytes, and some characteristics of the enzyme and effects of some metal ions on enzyme activity were investigated. For this purpose, erythrocyte glutathione S-transferase enzyme which has 16.54 EU/mg protein specific activities was purified 11,026-fold by glutathione-agarose affinity chromatography with a yield of 59%. Temperature was kept under control (+4 degrees C) during purification. Enzyme purification was checked by performing SDS-PAGE. Optimal pH, stable pH, optimal temperature, and K-M and V-max values for GSH and 1-chloro-2, 4-dinitrobenzene (CDNB) were also determined for the enzyme. In addition, IC50 values, K-i constants and the type of inhibition were determined by means of Line-Weaver-Burk graphs obtained for such inhibitors as Ag+; Cd2+, Cr2+ and Mg2+.