Pyruvate kinase activity and response to allosteric effectors in rat erythrocytes and reticulocytes fractionated by multiple partitioning in aqueous two-phase systems.
Specific activity of pyruvate kinase decreases as the age of rat erythrocytes increases in fractions obtained by counter-current distribution in dextran-polyethylene glycol biphasic systems; the enzyme is inhibited by ATP and activated by fructose-1,6-bisphosphate at low phosphoenol pyruvate concentrations. Specific activity does not change in fractions from greater than 95 per cent-rich reticulocytes (anaemic rats); the enzyme is inhibited by ATP but not activated by fructose-1,6-bisphosphate. These results can be explained on the basis of different pyruvate kinase isozymes and suggest that decrease in activity is not affecting regulatory properties during erythrocytes aging.
Pinilla
M
M
Departamento de Bioquímica y Biologia Molecular, Facultad de Farmacia, Universidad de Alcalá de Henares, Madrid, Spain.
Rodriguez-Horche
P
P
Luque
J
J
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000494:Allosteric Regulation; D000818:Animals; D002469:Cell Separation; D004905:Erythrocyte Aging; D004912:Erythrocytes / Q000201:enzymology*; D005635:Fructosediphosphates / Q000494:pharmacology; D008297:Male; D011770:Pyruvate Kinase / Q000037:antagonists & inhibitors / Q000097:blood*; D051381:Rats; D011919:Rats, Inbred Strains; D012156:Reticulocytes / Q000201:enzymology*
D005635:Fructosediphosphates; D000255:Adenosine Triphosphate; D011770:Pyruvate Kinase; C029063:fructose-1,6-diphosphate