The Loss of Enzyme Activity from Erythroid Cells During Maturation

Abstract

Erythrocyte enzyme activities in patients with reticulocytosis or transient erythroblastopenia show that loss of age-dependent enzyme activity is not a simple exponential process occurring throughout the life-span of the cell. In vivo studies of reticulocyte maturation in rabbits indicate that there are multiple mechanisms of enzyme decay, and that proteolysis continues after the maturation of (morphologically recognisable) reticulocytes into young erythrocytes. Most reticulocyte hexokinase is degraded by lysosomal proteolysis, apparently triggered by an initial attack by lipoxygenase.