Some metals inhibit the glutathione S-transferase from Van Lake fish gills.

Glutathione S-transferases (GSTs) are the superfamily of multifunctional detoxification isoenzymes and play important role cellular signaling. The present article focuses on the role of Cd , Cu , Zn , and Ag in vitro inhibition of GST. For this purpose, GST was purified from Van Lake fish (Chalcalburnus tarichii Pallas) gills with 110.664 EU mg specific activity and 79.6% yield using GSH-agarose affinity chromatographic method. The metal ions were tested at various concentrations on in vitro GST activity. IC values were found for Cd , Cu , Zn , Ag as 450.32, 320.25, 1510.13, and 16.43 μM, respectively. K constants were calculated as 197.05 ± 105.23, 333.10 ± 152.76, 1670.21 ± 665.43, and 0.433 ± 0.251 μM, respectively. Ag showed better inhibitory effect compared with the other metal ions. The inhibition mechanisms of Cd and Cu were non-competitive, whereas Zn and Ag were competitive. Co , Cr , Pb , and Fe had no inhibitory activity on GST.