Human platelet 6-phosphofructokinase . Purification, kinetic parameters and the influence of sulphate ions on enzyme activity

Abstract

1. 1.|Human platelet 6-phosphofructokinase (ATP:-fructose 6-phosphate 1-phosphotransferase, EC 2.7.1.11) was partially purified. The final preparation had a specific activity of 7.1 μmoles Fru-1,6-P2 formed per min per mg protein at 25 °C.

2. 2.|SO42− activated the enzyme activity especially at low Fru-6-P concentrations. This effect is due to diminished cooperativity with respect to Fru-6-P.

3. 3.|SO42− diminished the allosteric inhibition by ATP. Other nucleotide phosphates caused no inhibition when tested in the presence of 3 mM SO42−. In the absence of SO42− CTP also inhibited enzyme activity.