Purification and physical properties of hexokinase from human erythrocytes

A bulk purification is described for hexokinase (ATP:D-hexose 6-phosphotransferase, EC 2.7.1.1) from human erythrocytes. Following a 110,000-fold purification from 40 litres of blood, 5 mg protein with a specific activity of 22 units/mg were obtained. On application of various separation techniques, the enzyme activity co-migrated with the main protein component. The physical properties, such as the relative molecular mass of 108,000 and sedimentation coefficient of 5.5 S, are similar to those of the enzyme from human heart. In particular, there is a correspondence in the conformational response to glucose 6-phosphate as shown by an association of the enzyme promoted by this metabolite.