Electrophoretic and kinetic studies of a mutant red cell pyrimidine 5'-nucleotidase

Abstract

Human red cell pyrimidine 5'-nucleotidase (P5N) was studied by partial purification and condensation in a patient with an extremely low red cell P5N activity and chronic hemolytic anemia. The residual P5N in the red cell of the patient was characterized by an increased Michaelis constant for cytidine 5'-monophosphate, a marked shift of the pH optimum to the acidic side, normal electrophoretic mobility and normal heat stability. These data indicate that, in this patient, severe enzyme deficiency is caused by a structural gene mutation. This variant is clearly distinguished from a previously reported case and it is designated P5N Kagoshima.