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Concomitance of an Active and an Inactive Mutant of Red Cell Pyruvate Kinase (PK)
Author(s) -
Zanella A.,
Rebulla P.,
Izzo C.,
Zanuso F.,
Sirchia G.
Publication year - 1979
Publication title -
scandinavian journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.904
H-Index - 84
eISSN - 1600-0609
pISSN - 0036-553X
DOI - 10.1111/j.1600-0609.1979.tb00415.x
Subject(s) - isoelectric point , mutant , guanosine , enzyme , biochemistry , pyruvate kinase , isozyme , chemistry , cytidine , microbiology and biotechnology , red cell , structural gene , enzyme assay , gene , biology , glycolysis , medicine
A new mutant red cell PK associated with mild chronic haemolytic anaemia is described. The propositus, double heterozygous for a maternal gene coding for a structural abnormal enzyme and a paternal gene coding for a catalitically inactive enzyme, was suitable for an accurate functional characterization of the PK variant since his erythrocytes contained only one active mutant form of this enzyme. The active isoenzyme was characterized by low activity, decreased affinity for phospho‐enolpyruvate, incomplete fructose‐1,6‐diphosphate activation, increased ‘zero‐time transition temperature’, increased stability to guanidine‐HCl and storage at + 4° C, increased guanosine‐5′‐diphosphate and cytidine‐5′‐diphosphate utilization, altered elec‐trophoretic pattern with a single slow‐moving component and abnormal isoelectric point. Affinity for ADP, ATP inhibition, optimum pH, molecular weight of the sub‐units, antigen concentration and immunological properties were in the normal range.