Purification and characterization of glutathione reductase from turkey liver

This study aimed to purify glutathione reductase (GR) from turkey liver and investigate some of its characteristic features. The purification procedure comprised 2 steps: homogenate preparation and 2',5'-ADP Sepharose 4B affinity gel chromatography. Thanks to the 2 consecutive procedures, the enzyme, having the specific activity of 606.67 EU mg protein(-1), was purified with a yield of 10.75% and 2476-fold, and, in order to control enzyme purity, SDS-PAGE was done. Optimal pH, stable pH, optimal temperature, optimal ionic strength, molecular weight, turnover number of enzyme, and k(cat)/K-M and K-M and V-max values for NADPH and glutathione disulfide substrates were also determined for the enzyme. In addition, K-i constants and the type of inhibition were determined by means of Lineweaver-Burk graphs obtained for such inhibitors as NADP+ and glutathione. In conclusion, glutathione reductase enzyme was isolated and characterized from turkey liver for the first time, and some of its kinetic properties were determined.