Purification and characterization glutathione S-transferase enzyme from quail (Coturnix, coturnix japonica) heart and investigation the effect of some metal ions on enzyme activity

Abstract

In this study glutathione S-transferase enzyme (EC: 2.5.1.18) from the heart of japonica quail was purified with 34.0 EU/mg specific activity, 10.44% purification yield and 78.29 purification folds and characterized. Purification processes are consist of three steps, firstly homogenate was prepared, and then ammonium sulfate precipitation was performed and finally glutathione-agarose gel affinity column chromatography was performed. To check the purity of GST enzyme used SDS-PAGE method. Then the M.W calculated at approximately 26.3 kDa by SDS-PAGE method. Enzymatic activity was determined spectrofotometrically according to Beutler`s method at 340 nm. Also characterizations study carry out, and the results obtained are stability-pH = 9.0 in Tris/HCL buffer, optimum pH = 8.0 in Tris/HCl buffer, optimum temperature 60 °C, optimum ionic strength was 1.2 M in Tris/HCl buffer. And kinetic studies performed for GST enzyme purified from quail heart by used both glutathione and 1-chloro 2,4-dinitrobenzen as substrate. KM and Vmax values are determined as 1.642 mM and 0.502 EU/mL respectively for GSH substrate and 3.880 mM and 0.588 EU/mL respectively for CDNB substrate. In addition, the effect of some metal ions (Cu2+, Cd2+, Fe2+, Fe3+ Zn2+, Ag+, Co2+, and Ti1+) were investigated on the GST enzyme activity in vitro.