Andrés V, García-Salguero L, Gómez M E, Aragón J J
Instituto de Investigaciones Biomédicas del CSIC, Departamento de Bioquímica de la Facultad de Medicina de la Universidad Autónoma, Madrid, Spain.
FEBS Lett. 1988 Dec 5;241(1-2):51-4. doi: 10.1016/0014-5793(88)81029-9.
It has been found that the inhibition of Dictyostelium discoideum fructose-1,6-bisphosphatase by fructose 2,6-P2 greatly diminished when the pH was raised to the range 8.5-9.5, which resulted in a marked decrease of the affinity for the inhibitor with no change in the Km for the substrate. This provides evidence for the involvement of an allosteric site for fructose 2,6-P2. Moreover, the fact that excess substrate inhibition also decreased at the pH values for minimal fructose 2,6-P2 inhibition, and was essentially abolished in the presence of fructose 2,6-P2, strongly suggests that this inhibition takes place by binding of fructose 1,6-P2 as a weak analogue of the physiological effector fructose 2,6-P2.
