Glutathione reductase (Glutathione: NADP^+ oxidoreductase, EC 126.96.36.199; GR) was purified from sheep liver. The purification included 4 steps: preparation of homogenate, ammonium sulfate fractionation, 2', 5'-ADP Sepharose-4B affinity chromatography, and gel filtration chromatography. GR was obtained with a yield of 14.1% having a specific activity of 47.27 EU/mg proteins. Optimal pH, stable pH, and optimal temperature were 8.0, 5.5, and 60 °C, respectively. K_M and V_max values for NADPH and GSSG substrates were 0.0258 and 0.0239 mM, and 0.266 and 0.255 EU/ml, respectively. The overall purification was about 1477-fold for liver GR. The enzyme activity was measured spectrophotometrically at 340 nm. In addition, K_i values of 4.367 and 0.4055 mM were determined by means of Lineweaver-Burk graphs for NADP^+ and GSH, respectively.
ULUSU, GÖKTUĞ; ERAT, MUSTAFA; ÇİFTÇİ, MEHMET; ŞAKİROĞLU, HALİS; and BAKAN, EBUBEKİR (2005) "Purification and Characterization of Glutathione Reductase from Sheep Liver," Turkish Journal of Veterinary & Animal Sciences: Vol. 29: No. 5, Article 5. Available at: https://journals.tubitak.gov.tr/veterinary/vol29/iss5/5