Activation of phosphofructokinase from rat liver by 6-phosphogluconate

Low concentrations of 6-phosphogluconate activated phosphofructokinase from rat liver. 6-phosphogluconate (0.2mM) lowered the concentration of fructose-6-phosphate required to achieve one-half the maximum velocity (S0 · 5) to a value within the physiological range of fructose-6-phosphate concentrations, but had no effect on the maximum velocity. 6-phosphogluconate also changed the kinetics of the enzyme from sigmoidal to hyperbolic. The effect of 6-phosphogluconate on phosphofructokinase was abolished by heating the enzyme.