The assay of uridine diphosphoglucose dehydrogenase activity: discrimination from xanthine dehydrogenase activity.
The biochemical and quantitative cytochemical assays of the activity of uridine diphosphoglucose dehydrogenase (UDPG-D) have produced perplexing results. It is now shown that the perplexity may be due to the possibility that the coenzyme (NAD) required for UDPG-D activity, may be acting as a substrate for a second dehydrogenase, namely xanthine dehydrogenase, which may utilize NAD as its substrate. The activity of UDPG-D can be distinguished selectively by the pH of its optimal activity and by decreasing the concentration of the coenzyme used in the assay.
Unit of Cellular Pharmacology and Toxicology, Robens Institute of Health and Safety, University of Surrey, Guildford, U.K.
S
S
Mehdizadeh
L
L
Bitensky
J
J
Chayen
D000818:Animals; D002358:Cartilage, Articular / Q000201:enzymology; D004795:Enzyme Stability / Q000187:drug effects; D005260:Female; D007700:Kinetics; D008773:Methylphenazonium Methosulfate / Q000494:pharmacology; D051379:Mice; D008808:Mice, Inbred CBA; D009243:NAD / Q000494:pharmacology; D011190:Potassium Cyanide / Q000494:pharmacology; D014533:Uridine Diphosphate Glucose Dehydrogenase / Q000378:metabolism*; D014968:Xanthine Dehydrogenase / Q000378:metabolism*
D009243:NAD; D008773:Methylphenazonium Methosulfate; D014533:Uridine Diphosphate Glucose Dehydrogenase; D014968:Xanthine Dehydrogenase; D011190:Potassium Cyanide