Intracellular glucose-6-phosphate dehydrogenase does not monomerize in human erythrocytes.
Glucose-6-phosphate dehydrogenase functions within human erythrocytes at a rate far less than expected from kinetic properties of the purified enzyme and from estimated concentrations of enzyme, substrates, and products. Several investigators have proposed that activity of glucose-6-phosphate dehydrogenase is less than maximal because the enzyme is regulated by equilibration between an active dimeric form of the enzyme and an inactive monomer. The phenomenon of Lyonization provided an opportunity for this proposal to be tested. Erythrocytes of a glucose-6-phosphate dehydrogenase A/B heterozygous woman were gently lysed and resealed so that each erythrocyte contained the two homodimers AA and BB. Subsequent lysis and electrophoresis revealed no heterodimer. This finding indicates that intracellular factors other than reversible dissociation account for the restraint of human glucose-6-phosphate dehydrogenase.
D004588:Electrophoresis, Cellulose Acetate; D004912:Erythrocytes / Q000201:enzymology*; D005260:Female; D005954:Glucosephosphate Dehydrogenase / Q000097:blood*; D006801:Humans; D007700:Kinetics; D046911:Macromolecular Substances; D008297:Male
D046911:Macromolecular Substances; D005954:Glucosephosphate Dehydrogenase