Relative deficiency of Ca2 plus-dependent adenosine triphosphatase activity of red cell membranes in hereditary spherocytosis

The Ca²⁺-dependent adenosine triphosphatase activity associated with the plasma membrane of normal human erythrocytes is similar to that of erythrocytes from patients with hereditary spherocytosis. When spherocytic ghosts are compared to age-matched controls, however, they show a significantly decreased Ca²⁺-dependent adenosine triphosphatase activity. The role of the relative deficiency of Ca²⁺-dependent adenosine triphosphatase in spherocytic ghosts is discussed in the light of the effects of intracellular Ca²⁺] on the deformability and the rigidity of the cell membrane. This enzyme may be involved in the molecular mechanism of hereditary spherocytosis.