Effects of 1,5-anhydro-D-fructose on selected glucose-metabolizing enzymes.
It was verified, by n.m.r. and fast-atom-bombardment-m.s. studies, that the C-2 position of 1,5-anhydro-D-fructose, which was prepared by the reaction of immobilized glucose 2-oxidase from Coriolus versicolor (with 1,5-anhydro-D-glucitol), is hydrated to the acetal form in water. The effects of 1,5-anhydro-D-fructose on several glucose-metabolizing enzymes were compared with those of 1,5-anhydro-D-glucitol. Glucose 1-oxidase from Aspergillus niger was inhibited by 1,5-anhydro-D-fructose (Ki 6.6 mM) more effectively than 1,5-anhydro-D-glucitol (Ki 82.5 mM). Yeast and rat brain hexokinases phosphorylated 1,5-anhydro-D-fructose (Km,yeast 2.3 mM: Km,rat 0.79 mM) and 1,5-anhydro-D-glucitol (Km,yeast 3.9 mM; Km,rat 0.83 mM). The phosphorylated forms of these compounds inhibited D-glucose phosphorylation by yeast hexokinase (Ki of phosphorylated 1,5-anhydro-D-fructose 0.11 mM; Ki of phosphorylated 1,5-anhydro-D-glucitol 0.38 mM) and rat brain hexokinase (Ki of phosphorylated 1,5-anhydro-D-fructose 0.07 mM; Ki of phosphorylated 1,5-anhydro-D-glucitol 0.04 mM). Glucokinase phosphorylated neither 1,5-anhydro-D-fructose nor 1,5-anhydro-D-glucitol, and the phosphorylation of D-glucose by glucokinase was inhibited by them. Mutarotase was slightly inhibited by 1,5-anhydro-D-fructose, as well as by 1,5-anhydro-D-glucitol.
Taguchi
T
T
Department of Clinical Biochemistry, Faculty of Pharmacy, Meijo University, Nagoya, Japan.
Haruna
M
M
Okuda
J
J
D001234:Aspergillus niger / Q000201:enzymology; D002237:Carbohydrate Dehydrogenases / Q000037:antagonists & inhibitors*; D002238:Carbohydrate Epimerases / Q000037:antagonists & inhibitors*; D003847:Deoxyglucose / Q000737:chemistry / Q000494:pharmacology; D005632:Fructose / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D005941:Glucokinase / Q000037:antagonists & inhibitors*; D005947:Glucose / Q000378:metabolism; D006593:Hexokinase / Q000037:antagonists & inhibitors*; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D010766:Phosphorylation; D016339:Spectrometry, Mass, Fast Atom Bombardment
D005632:Fructose; C006584:1,5-anhydroglucitol; C048927:1,5-anhydrofructose; D003847:Deoxyglucose; D002237:Carbohydrate Dehydrogenases; C022489:pyranose oxidase; D006593:Hexokinase; D005941:Glucokinase; D002238:Carbohydrate Epimerases; C019646:aldose 1-epimerase; D005947:Glucose