Dephosphorylation and reactivation of phosphorylated pyruvate kinase by a cytosolic phosphoprotein phosphatase from human erythrocytes

Abstract

A cytosolic phosphoprotein phosphatase activity which is capable of removing the phosphate group from phosphorylated human erythrocyte pyruvate kinase has been found in the red blood cell. Removal of the phosphate group results in the reactivation of the pyruvate kinase. The phosphatase is not markedly sensitive to fluoride or chelating agents; it is inhibited by ligands containing phosphate groups. Adenosine diphosphate was found to be the most effective inhibitor. Gel filtration of the preparation suggests that there is more than one form of phosphatase present