Fructose 2,6-biphosphate sodium salt is a potent stimulator of 6-Phosphofructo-1-kinase (PFK-1) and also inhibits Fructose-1,6-Bisphosphatase[1]. PFK-1, Fructose-1,6-Bisphosphatase[1]
A concentration-dependent inhibition of fructose-1,6-Bisphosphatase by Fructose 2,6-bisphosphate is observed. Another characteristic of this inhibition is that it changes the saturation curve from hyperbolic to sigmoidal. This effect is clearly apparent at 25 pM Fructose 2,6-bisphosphate. It appears that the inhibitory actions of Fructose 2,6-bisphosphate and of AMP are synergistic. Indeed, at 10 pM fructose 1,6-bisphosphate, the addition of AMP alone causes a 35% inhibition but, it increases the inhibition by 1 pM Fructose 2,6-bisphosphate from 20% to 80%[1].
[1]. Van Schaftingen E, et al. Inhibition of fructose-1,6-bisphosphatase by fructose 2,6-biphosphate. Proc Natl Acad Sci U S A. 1981 May;78(5):2861-3.