Purification and Characterization of Glutathione Reductase Enzyme from Arum Maculatum Leaf

Abstract

Arum species grow in temperate and Mediterranean climates and have been used for hundreds of years for food and medicinal purposes, although they are highly toxic if not cooked using proper techniques. Glutathione reductase is a member of the pyridine nucleotide disulfide oxidoreductase family of flavoenzymes that catalyzes the reduction of glutathione disulfide (GSSG) to reduced GSH using NADPH or NADH. GR has a key role in the intracellular glutathione reduction-oxidation process since GSSG is formed as a result of the reactions catalyzed by the antioxidant enzyme glutathione peroxidase, especially the detoxification of hydroperoxides and the reduction of some compounds. In this study, GR enzyme was characterized by partial purification processes including homogenate preparation, ammonium sulfate precipitation and dialysis from the leaf of Arum maculatum plant. The highest enzyme activity was found at 40-60% saturation range. Optimum ionic strength, pH and substrate concentration were investigated for GR enzyme from A. maculatum leaf. As a result of the study, these values were found to be 150 mM potassium phosphate buffer, pH 7.00, and 0.18 mM, respectively. The GR enzyme was partially purified from the leaf of the A. maculatum with a specific activity of 1.640 EU mg-1 in 34.9% yield, 1.108-fold. This study is the first study in terms of purification and characterization of GR enzyme from A. maculatum leaf.