Identification of mutants of pyruvate kinase from red blood cells by means of trypsinization, electrophoresis, kinetic properties and immunological methods.

Enzymopathies of pyruvate kinase (PK) are characterized by polymorphism. 11 different mutants of PK were detected in 12 analysed cases. The frequency of double heterozygotes of the PK deficiency is very high. The mutant forms have been identified by electrophoretic, kinetic and immunologic methods in red blood cells of patients and members of their families. The effect of trypsin has greatly increased the sensitivity of the differentiation procedures. Differences in activity and quality of the proteolytic systems in liver and kidney in comparison to red blood cells are responsible for inactivation and degradation of PK mutants in both organs. Homozygotes and double heterozygotes show clinic manifestations. The rigidity of red blood cells increases with the severity of the nonspherocytic haemolytic anaemia.