title: Cooperation of fructose-2,6-bisphosphate and AMP in the activation of yeast phosphofructokinase.
abstract: Yeast phosphofructokinase is effectively activated by AMP and fructose-2,6-bisphosphate. Both effectors influence the sensitivity of the enzyme with respect to fructose-6-phosphate and increase the respective maximum activities. The dependence of phosphofructokinase activity on the concentration of fructose-2,6-bisphosphate was measured at different AMP concentrations and vice versa. By AMP the half activation constant for fructose-2,6-bisphosphate is decreased by one order of magnitude. The affinity to AMP is significantly increased by fructose-2,6-bisphosphate. AMP increases the maximum activity of the enzyme with respect to fructose-2,6-bisphosphate only slightly, while the maximum activity with respect to AMP is drastically increased by fructose-2,6-bisphosphate. The interaction of the two activators is most pronounced at low levels of fructose-6-phosphate and at high concentrations of ATP.
mesh_terms: D000249:Adenosine Monophosphate / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D005635:Fructosediphosphates / Q000494:pharmacology*; D006598:Hexosediphosphates / Q000494:pharmacology*; D007700:Kinetics; D010732:Phosphofructokinase-1 / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
chemical_list: D005635:Fructosediphosphates; D006598:Hexosediphosphates; D000249:Adenosine Monophosphate; C027652:fructose 2,6-diphosphate; D010732:Phosphofructokinase-1