Stimulation of Spermatid Phosphofructokinase by Fructose 2,6-Bisphosphate from Rat Testes

(fructose 2, 6-bisphosphate/phosphofructokinase/spermatids/rats)



Effect of fructose 2, 6-bisphosphate on 6-phosphofructokinase (ATP: D-fructose-6-phosphate 1-phosphotransferase, EC in spermatid extract from rat testes was studied. Fructose 2, 6-bisphosphate stimulated the enzyme greatly by increasing its affinity for fructose 6-phosphate and relieving the inhibition by ATP. Fructose 2, 6-bisphosphate (0.8 μM) was required for 50% activation of 6-phosphofructokinase (PFK). In addition, fructose 2, 6-bisphosphate, AMP and fructose 6-phosphate acted cooperatively to stimulate the activity of PFK. This stimulation may play an important role in the regulation of glycolysis in spermatids of rat testes.