Increase in the phospholipid phase extractable by dry ether following ATP-depletion of erythrocytes

Treatment of fresh sheep erythrocytes with a mixture of pure sphingomyelinase and phospholipase-C (B. cereus) causes hydrolysis of 25% of the total phospholipids while the same treatment of ATP-depleted cells causes hydrolysis of 48% of the total phospholipids. Extraction with dry ether of fresh sheep and rat erythrocytes results in the extraction of 20-25% and 40% of the phospholipids respectively. When ATP-depleted cells were extracted with dry ether in the same way the amount of phospholipids extracted was increased to 40% in sheep erythrocytes and 60% in rat erythrocytes. Interpretation of the results suggests that ATP depletion of cells induces significant alteration of protein-lipid interaction in the erythrocyte membrane.