Additional Kinetic Distinctions Between Normal Pyruvate Kinase and a Mutant Isozyme From Human Erythrocytes. Correction of the Kinetic Anomaly by Fructose-1,6-diphosphate

Several cases have been reported in which chronic hemolytic anemia was thought to be secondary to the same mutant isozyme of erythrocyte PK. In crude hemolysates from one of these cases, defective kinetic characteristics of the isozyme were found to be completely correctable in vitro by low concentrations of the PK activator, fructose-1,6-diphosphate. The patterns of response to the activator further distinguished this isozyme from normal PK and suggested that the isozymes in these cases, previously thought to be identical, more probably represent three subtly distinct mutant forms.