Human erythrocyte phosphofructokinase: Its Purification and some properties

Abstract

1. 1. Human erythrocyte phosphofructokinase (ATP:-fructose 6-phosphate 1-phosphotransferase, EC 2.7.1.11) was purified 15 000-fold by (NH4)2SO4 precipitation, heating and column chromatography on Sepharose 6-B. The resulting enzyme preparation had a specific activity of 60 μmoles Fru-1,6-P2 formed per min per mg protein at 25 °C.

2. 2. With cellulose-acetate electrophoresis only one band was observed after detection of the enzyme activity with the fluorescent technique.

3. 3. Citrate and 2,3-diphosphoglycerate do not inhibit. The inhibition by ATP is pH dependent. Cyclic AMP is able to reverse the inhibition by ATP to some extent.

4. 4. With GTP, ITP and UTP no inhibition is observed. At saturating concentrations of GTP, ATP still inhibits phosphofructokinase.

5. 5. The variation of the activity of phosphofructokinase at various ATP and Fru-6-P concentrations was studied. In the reaction mechanism a ternary complex is involved.