On the regulatory properties of the pyruvate kinase from Trypanosoma cruzi epimastigotes.
The pyruvate kinase from Trypanosoma cruzi epimastigotes was activated by fructose 2,6-diphosphate ((A) 0.5 = 0.17 microM), through a decrease in (S) 0.5 and an increase in Vmax for both substrates. The enzyme was 50% inhibited by 0.9 mM ATP or 0.5 mM Pi in the presence of 30 mM MgCl2; these inhibitions were completely counteracted by 1.5 microM fructose 2,6-diphosphate. Both facts suggest that the effects are allosteric, and not due to chelation.
Cazzulo
J J
JJ
Instituto de Investigaciones Bioquimicas Fundacion Campomar, Buenos Aires, Argentina.
Cazzulo Franke
M C
MC
Franke de Cazzulo
B M
BM
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D004789:Enzyme Activation / Q000187:drug effects; D005635:Fructosediphosphates / Q000494:pharmacology; D007700:Kinetics; D010710:Phosphates / Q000494:pharmacology; D011770:Pyruvate Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014349:Trypanosoma cruzi / Q000201:enzymology* / Q000254:growth & development
D005635:Fructosediphosphates; D010710:Phosphates; C027652:fructose 2,6-diphosphate; D000255:Adenosine Triphosphate; D011770:Pyruvate Kinase