A specific enzyme for glucose 1,6-bisphosphate synthesis.
The reaction: glycerate-1,3-P2 PLUS GLUCOSE-1-P YIELDS TO GLUCOSE-1,6-P2 plus glycerate-P is catalyzed by a distinct enzyme of mouse brain. A divalent metal requirement was shown when the enzyme was treated with imidazole and EDTA. Mg2+, Mn2+, Ca2+, Zn2+, Ni2+, Co2+, and Cd2+ were quite effective cofactors. The enzyme, in better than 50 percent yield, has been purified away from 99 percent of the phosphoglucomutase, phosphoglycrate mutase, and phosphofructokinase. Acetyl-P, ATP, enolpyruvate-P, creatine-P, and fructose-1,6-P2 are not phosphoryl donors. Glucose-6-P and mannose-1-P are good alternate acceptors. Mannose-6-P, galactose-Ps, and fructose-Ps have little or no acceptor activity. Strong inhibition was found with fructose-1,6-P2, glycerate-2,3-P2, enolpyruvate-P, and acetyl CoA. From the amount of activity and the kinetic constants of the purified enzyme it seems likely that this enzyme is responsible for the glucose-1,6-P2 synthesis of brain.
D000105:Acetyl Coenzyme A / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002413:Cations, Divalent / Q000494:pharmacology; D004163:Diphosphoglyceric Acids / Q000378:metabolism; D005636:Fructosephosphates / Q000494:pharmacology; D005958:Glucosephosphates / Q000096:biosynthesis*; D006598:Hexosediphosphates / Q000096:biosynthesis*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008358:Mannose / Q000378:metabolism; D051379:Mice; D010728:Phosphoenolpyruvate / Q000494:pharmacology; D010770:Phosphotransferases / Q000378:metabolism*
D002413:Cations, Divalent; D004163:Diphosphoglyceric Acids; D005636:Fructosephosphates; D005958:Glucosephosphates; D006598:Hexosediphosphates; D000105:Acetyl Coenzyme A; D010728:Phosphoenolpyruvate; D010770:Phosphotransferases; D008358:Mannose