Comparative Study of Human M2-Type Pyruvate Kinases Isolated from Human Leukocytes and Erythrocytes of a Patient with Red Cell Pyruvate Kinase Hyperactivity

Abstract

M(2)-type pyruvate kinases (M(2)-PK) have been isolated from human leukocytes and from the erythrocytes of a patient with erythrocyte PK hyperactivity. The kinetic characteristics of the patient erythrocyte M(2)-PK were similar to those of leukocyte M(2)-PK except for the Hill coefficient of phosphoenol pyruvate kinetics that showed little difference in the values. The patient erythrocyte M(2)-PK displayed complete immunological identity with leukocyte M(2)-PK in immunodiffusion, immunoblotting and immunoneutralization. The sensitivity to proteolysis by trypsin and the electrophoretic migration in different conditions were similar for the M(2)-PK of both origins. These results suggest an identity between this M(2)-PK abnormally present in erythrocytes and the M(2)-PK from leukocytes.