Hexokinase isoenzymes in human erythrocytes: association of type II with fetal hemoglobin.

Hexokinase activity in human erythrocytes is associated with three electrophoretically distinct bands. Normal adult erythrocytes contain hexokinases Types I and III. Type II hexokinase is present in the erythrocytes of newborn infants and absent from those of normal adults; it is, however, present in erythrocytes of adults with hereditary persistence of fetal hemoglobin. Type II hexokinase and fetal hemtoglobin appear to be associated.