Solubilization and Partial Purification of the Plasma Membrane ATPase of Rhodotorula glutinis

The optimal conditions for solubilization of the ATPase activity from the plasma membrane of Rhodotorula glutinis by zwitterionic detergent Z-3-14 were found to be: 0.55 mg/ml (5X cmc) of Z-3-14, at room temperature in the presence of 1 mM ATP, 40% (v/v) glycerol, 11.25% ammonium sulfate, 5 mM 2- mercaptoethanol, 1 mM PMSF in 0.1 M Mes-Tris pH 6.5, followed by sonication in a water bath sonicator for 6 min. A 4-fold purification of the solubilized ATPase activity was obtained by entrifugation of the Z-3-14 extract through a glycerol gradient (20-50%, v/v).