Spectrin phosphorylation in intact neonatal and adult erythrocyte membranes.

The erythrocyte of the human neonate exhibits clustering and endocytosis of membrane receptors in response to the plant lectin concanavalin A, but erythrocytes from adults do not. Because the phosphorylation of spectrin has been postulated to influence protein mobility in human erythrocyte membranes, the phosphorylation of spectrin was compared in intact neonatal and adult human erythrocytes. No difference in spectrin phosphorylation was seen. The addition of concanavalin A under conditions which produce protein mobility resulted in no change in spectrin phosphorylation.