Fructose 2,6-bisphosphate in rat erythrocytes. Inhibition of fructose 2,6-bisphosphate synthesis and measurement by glycerate 2,3-bisphosphate.
The concentration of fructose 2,6-bisphosphate found in freshly isolated erythrocytes was below the limit of detection (20 pmol/ml of packed cells). However, it increased to about 250 pmol/ml of cells when erythrocytes were incubated with glucose at pH 6.9, but not at pH 7.4 or 8.2. This could be explained by variations in the content of glycerate 2,3-bisphosphate, which was found to inhibit 6-phosphofructo-2-kinase, the enzyme responsible for fructose 2,6-bisphosphate synthesis. Glycerate 2,3-bisphosphate was also found to inhibit the potato enzyme (pyrophosphate:fructose-6-phosphate 1-phosphotransferase) used for the measurement of fructose 2,6-bisphosphate.
Sobrino
F
F
Department of Biochemistry, Faculty of Medicine, University of Sevilla, Spain.
Rider
M H
MH
Gualberto
A
A
Hue
L
L
D019794:2,3-Diphosphoglycerate; D000818:Animals; D004163:Diphosphoglyceric Acids / Q000494:pharmacology*; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D005635:Fructosediphosphates / Q000097:blood*; D005947:Glucose / Q000494:pharmacology; D006598:Hexosediphosphates / Q000097:blood*; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008297:Male; D025481:Phosphofructokinase-2; D010770:Phosphotransferases / Q000037:antagonists & inhibitors / Q000097:blood; D051381:Rats; D011919:Rats, Inbred Strains
D004163:Diphosphoglyceric Acids; D005635:Fructosediphosphates; D006598:Hexosediphosphates; D019794:2,3-Diphosphoglycerate; C027652:fructose 2,6-diphosphate; D010770:Phosphotransferases; D025481:Phosphofructokinase-2; C022502:pyrophosphate-fructose 6-phosphate 1-phosphotransferase; D005947:Glucose