Characteristics of hexokinase, pyruvate kinase, and glucose‐6‐phosphate dehydrogenase during adult and neonatal reticulocyte maturation
G Jansen, L Koenderman, G Rijksen… - American journal of …, 1985 - Wiley Online Library
G Jansen, L Koenderman, G Rijksen, BP Cats, GEJ Staal
American journal of hematology, 1985•Wiley Online LibraryErythrocytes from adults and newborn infants (at term and premature) were separated by
Percoll density gradient centrifugation into four fractions of increasing density. Glycolytic
enzymes, especially the age‐dependent ones, hexokinase (EC 2.7. 1.1, HK), pyruvate
kinase (EC 2.7. 1.40, PK), and glucose‐6‐phosphate dehydrogenase (EC 1.1. 1.49, G6PD)
were studied during reticulocyte maturation and further red cell senescence. Analysis of the
fraction with lowest density showed an almost linear and steep decline of HK, PK, and G6PD …
Percoll density gradient centrifugation into four fractions of increasing density. Glycolytic
enzymes, especially the age‐dependent ones, hexokinase (EC 2.7. 1.1, HK), pyruvate
kinase (EC 2.7. 1.40, PK), and glucose‐6‐phosphate dehydrogenase (EC 1.1. 1.49, G6PD)
were studied during reticulocyte maturation and further red cell senescence. Analysis of the
fraction with lowest density showed an almost linear and steep decline of HK, PK, and G6PD …
Abstract
Erythrocytes from adults and newborn infants (at term and premature) were separated by Percoll density gradient centrifugation into four fractions of increasing density. Glycolytic enzymes, especially the age‐dependent ones, hexokinase (EC 2.7.1.1, HK), pyruvate kinase (EC 2.7.1.40, PK), and glucose‐6‐phosphate dehydrogenase (EC 1.1.1.49, G6PD) were studied during reticulocyte maturation and further red cell senescence.
Analysis of the fraction with lowest density showed an almost linear and steep decline of HK, PK, and G6PD activity with a decreasing number of reticulocytes. In the next three fractions of increasing density, the activity decline was far less. These data are therefore illustrative for a biphasic activity decay pattern of HK, PK, and G6PD during both adult and neonatal red cell aging.
The strong decline in HK activity could not be ascribed to the disappearance of a particulate (mitochondrial) bound fraction of the enzyme during reticulocyte maturation. All hexokinase activity in human reticulocytes was found to be cytosolic in contrast with rabbit reticulocytes in which 70% of HK activity was particulate.
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