PARTIAL CHARACTERIZATION OF A GLUTATHIONE OXIDASE PRESENT IN RAT-KIDNEY PLASMA-MEMBRANE FRACTION

The previously reported glutathione oxidizing activity of isolated renal cells was recovered in the plasma membrane fraction of a rat kidney homogenate. Glutathione disulfide and hydrogen peroxide were formed during the reaction which was dependent on the access to molecular oxygen and inhibited by KCN and EDTA, but not by NaN3. The EDTA-inhibited activity could be restored by addition of CuSO4, but not FeCl3, to the plasma membrane fraction after dialysis. The results strongly suggest that a Cu-protein present in the plasma membrane is responsible for the glutathione oxidase activity of renal cells. © 1979.