The effect of substitution at C-2 of D-glucose 6-phosphate on the rate of dehydrogenation by glucose 6-phosphate dehydrogenase (from yeast and from rat liver).
1. The deoxyfluoro-d-glucopyranose 6-phosphates are substrates for both yeast and rat liver glucose 6-phosphate dehydrogenase. 2. The V(max.) values (relative to d-glucose 6-phosphate) were determined for a series of d-glucose 6-phosphate derivatives substituted at C-2. The V(max.) values decreased with increasing electronegativity of the C-2 substituent. This is consistent with a mechanism involving hydride-ion transfer. 3. 2-Deoxy-d-arabino-hexose 6-phosphate (2-deoxy-d-glucose 6-phosphate) showed substrate inhibition with the yeast enzyme but not with the rat liver enzyme. 4. 2-Amino-2-deoxy-d-glucose 6-phosphate (d-glucosamine 6-phosphate) was a substrate for the yeast enzyme but a competitive inhibitor for the rat liver enzyme. 5. Lineweaver-Burk plots for the d-glucose 6-phosphate derivatives with yeast glucose 6-phosphate dehydrogenase were biphasic.
D000818:Animals; D001667:Binding, Competitive; D002848:Chromatography, DEAE-Cellulose; D003201:Computers; D003956:Dialysis; D005461:Fluorine / Q000378:metabolism; D005944:Glucosamine / Q000494:pharmacology; D005954:Glucosephosphate Dehydrogenase / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D005958:Glucosephosphates / Q000378:metabolism* / Q000494:pharmacology; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D008433:Mathematics; D008968:Molecular Conformation; D051381:Rats; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000201:enzymology*; D013056:Spectrophotometry, Ultraviolet; D013329:Structure-Activity Relationship
D005958:Glucosephosphates; D005461:Fluorine; D005954:Glucosephosphate Dehydrogenase; D005944:Glucosamine