Purification and Characterization of 6-Phosphogluconate Dehydrogenase from Japanese Quail (Coturnix, coturnix japonica) Erythrocytes

Abstract

In this study, the 6PGD enzyme from Japanese quail erythrocytes was purified with specific activity of 52.84 EU/mg and 69% yield of purification by 2ˈ, 5ˈ- ADP Sepharose 4B affinity gel in a single chromatographic method. The purification folds of the enzyme were 4984 folds. The purified enzyme was checked using SDS polyacrylamide gel electrophoresis (SDS-PAGE) method; the result of gel showed a single band. The subunit molecular weight of the enzyme was calculated as 81 kDa by the SDS-PAGE method. The characterization studies of the 6PGD enzyme from erythrocytes of Japanese quail showed: the optimum ionic strength to be at 0.5 M Tris-HCl, optimum and stable pH values to be at 0.5 M Tris-HCl buffers pH 8.0. The optimal temperature for the enzyme activity was found at 60 ˚C. Finally, the KM and Vmax values for the 6PGD enzyme from Japanese quail’s erythrocytes were calculated respectively for the 6PGA the KM value found as 0.120 mM, Vmax value as 0.191 EU/mL and for NADP+ the KM value as 0.017 mM and Vmax value as 0.228 EU/mL.