Why are ADP and AMP levels more sensitive as allosteric effectors than ATP?

Question

Why are ADP and AMP levels more sensitive as allosteric effectors than ATP?

Answer 1

Consider phosphofructokinase1 an enzyme which catalyses -

Fructose-6-P → Fructose-1,6-bisP.

Phosphofructokinase 1 is the first enzyme that is common to the many possible starting points for glycolysis, and is therefore a key point of regulation.

If ATP levels are low then the enzyme has to increase its activity and if ATP levels are low then AMP and ADP levels will be high.Thus AMP in particular will be a good allosteric activator.

Also from chemical equilibrium considerations (see link) AMP concentration varies as the square of [ADP], and is thus a more sensitive indicator of energy status and therefore a better allosteric activator (more sensitive)