title: Investigation of the UDP-glucose dehydrogenase reaction for a coupled assay of UDP-glucose pyrophosphorylase activities.
abstract: An optimized coupled enzyme assay for UDP-glucose pyrophosphorylase (EC 2.7.7.9) using UDP-glucose dehydrogenase (EC 1.1.1.22) is presented. This optimized assay was developed by a detailed investigation of the kinetics of the UDP-glucose dehydrogenase reaction. In addition the data provide a basis for the enzymatic synthesis of UDP-glucuronic acid. The results demonstrate that the two binding sites of the dehydrogenase differ since a different modulation of the enzyme activity and stability is observed after preincubation with UDP-glucose or NAD+ at various pH values. This is of general interest for the preparation of assay mixtures where UDP-glucose dehydrogenase is used as an auxiliary enzyme.
authors.affiliation: Institut für Enzymtechnologie, Heinrich-Heine Universität Düsseldorf im Forschungszentrum Jülich, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Elling
authors.forename: M R
authors.initials: MR
authors.lastname: Kula
mesh_terms: D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D005957:UTP-Glucose-1-Phosphate Uridylyltransferase / Q000032:analysis*; D014533:Uridine Diphosphate Glucose Dehydrogenase / Q000378:metabolism*
chemical_list: D014533:Uridine Diphosphate Glucose Dehydrogenase; D005957:UTP-Glucose-1-Phosphate Uridylyltransferase