A novel enzyme catalyzes the synthesis of activation factor from ATP and D-fructose-6-P.
We have recently discovered an activator for phosphofructokinase termed "activation factor" (Furuya, E., and Uyeda, K. (1980) Proc. Natl. Acad. Sci. U. S. A. 77, 5861-5864). In this paper, we investigated the enzyme responsible for its synthesis. We have found an enzyme from rat liver which catalyzes the formation of activation factor from fructose-6-P and ATP-Mg and it has been identified as fructose-2,6-P2. Fructose-1,6-P2, fructose-1-P, or fructose does not serve as a substrate. This enzyme has been partially purified and shown to be different from phosphofructokinase. Several lines of evidence indicate that the in vitro synthetic product is identical with chemically synthesized fructose-2,6-P2: (a) it is active in our assay for activation factor which is based on counteraction of ATP inhibition of phosphofructokinase; (b) it is acid labile as is fructose-2,6-P2; and (c) it shows the same mobility as synthetic fructose-2,6-P2 upon paper chromatography and the acid hydrolysis product has been identified as fructose-6-P. Thus, this new enzyme catalyzes the synthesis of the activation factor from fructose-6-P and ATP-Mg.
D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D004789:Enzyme Activation; D005635:Fructosediphosphates / Q000096:biosynthesis*; D005636:Fructosephosphates / Q000378:metabolism*; D006598:Hexosediphosphates / Q000096:biosynthesis*; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D010732:Phosphofructokinase-1 / Q000378:metabolism*; D051381:Rats
D005635:Fructosediphosphates; D005636:Fructosephosphates; D006598:Hexosediphosphates; C027618:fructose-6-phosphate; C027652:fructose 2,6-diphosphate; D000255:Adenosine Triphosphate; D010732:Phosphofructokinase-1