CHARACTERIZATION OF PLASMA-MEMBRANE REDOX ACTIVITY FROM EHRLICH CELLS

Ferricyanide reductase activity of plasma membranes isolated from Ehrl ich ascites tumour cells was very sensitive to trypsin treatment. The decreases of activity observed after treatment with different glycosid ases suggests that ferricyanide reductase is a glycoprotein. The oppos ite effects of phospholipase A(2) and phospholipase C on the redox act ivity indicate that the phospholipidic environment plays an important role in the function of ferricyanide reductase. Sodium ions at millimo lar concentrations, and some divalent cations at micromolar concentrat ions (Ca2+, Mg2+,Sr2+, and Mn2+) behaved as stimulators of ferricyanid e reductase activity.