Fructose 2,6-bisphosphate-dependent regulation of phosphofructokinase in rat submandibular gland.
1. Regulation of phosphofructokinase in rat submandibular gland was non-Michaelis-Menten type at physiological pH. 2. At pH 7.3, ATP played a dual role on phosphofructokinase acting as a substrate and inhibitor at high concentration of ATP. 3. The activator of phosphofructokinase was present in cytosol fraction, and its properties were resemble to those of fructose 2,6-bisphosphate. 4. Both the activator and authentic fructose 2,6-bisphosphate relieved the inhibition of phosphofructokinase by ATP, and increased the affinity for fructose 6-phosphate. 5. Concentration of fructose 2,6-bisphosphate in rat submandibular gland was 8.22 nmol/g tissue, and which was about the half of that in liver. 6. Phosphofructokinase in rat submandibular gland was found to be regulated synergistically by ATP, fructose 6-phosphate and fructose 2,6-bisphosphate.
Sugiya
H
H
Department of Physiology, Nihon University School of Dentistry, Matsudo, Chiba, Japan.
Fujita
Y
Y
Fukushima
E
E
Yamazaki
T
T
Furuyama
S
S
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D004789:Enzyme Activation; D005635:Fructosediphosphates / Q000378:metabolism*; D006598:Hexosediphosphates / Q000378:metabolism*; D008297:Male; D010732:Phosphofructokinase-1 / Q000378:metabolism*; D051381:Rats; D013363:Submandibular Gland / Q000201:enzymology*
D005635:Fructosediphosphates; D006598:Hexosediphosphates; C027652:fructose 2,6-diphosphate; D000255:Adenosine Triphosphate; D010732:Phosphofructokinase-1