Kinetic behaviour and regulatory properties of phosphofructokinase in rat bone marrow cells
Tejedor, M.C.; Ramírez, A.; Luque, J.
Biochemistry International 9(5): 577-586
1984
ISSN/ISBN: 0158-5231 PMID: 6098275 Document Number: 238697
Phosphofructokinase from bone marrow cells shows sigmoidal kinetics with respect to fructose-6-phosphate when studied at near physiological concentrations of ATP (1.5 mM) and pH (7.1). The enzyme is clearly inhibited by ATP concentrations higher than 0.75 mM. pH increases maximum velocity and affinity of the enzyme towards fructose-6-phosphate and decreases the cooperative behavior of the enzyme. Citrate behaves as a negative allosteric effector. ATP deinhibition and activation of bone marrow phosphofructokinase, by either AMP or cAMP, were also observed. cAMP seems to have a higher affinity for the enzyme than AMP. cGMP does not show any antagonistic effect versus cAMP as has been previously observed in rat erythrocytes or reticulocytes.