Isoelectric focussing of normal human erythrocyte pyruvate kinase (PK) and PK variants with abnormal electrophoretic patterns

Abstract

Isoelectric points of normal human erythrocyte pyruvate kinase (PK) and PK variants with abnormal electrophoretic patterns, were obtained by means of isoelectric focussing. The obtained isoelectric points of normal, PK Nagasaki, PK Tokyo II, PK Ube, and case T.S. were 7.36, 7.38, 7.05, 6.90, and 7.04, respectively, at 6°C. All of the PKs collected after isoelectric focussing were shown to be not of the L-type PK but to be the erythrocyte PK (by means of thin-layer-polyacrylamide gel electrophoresis). The PKs with fast migration had isoelectric points that were shifted to the acidic side as compared with those of the normal subjects. The PK with slow migration had an isoelectric point that was shifted to the alkaline side, demonstrating that the isoelectric points obtained by isoelectric focussing were consistent with the electrophoretic patterns of the crude hemolysates. Isoelectric focussing also revealed the existence of PK variants with abnormal electric net charge, just as well as thin-layer-poly-acrylamide gel electrophoresis.