title: Identification and characterization of UDP-glucose dehydrogenase from the hyperthermophilic archaon, Pyrobaculum islandicum.
abstract: A gene encoding a UDP-glucose dehydrogenase homologue was identified in the hyperthermophilic archaeon, Pyrobaculum islandicum. This gene was expressed in Escherichia coli, and the product was purified and characterized. The expressed enzyme is the most thermostable UDP-glucose dehydrogenase so far described, with a half-life of 10 min at 90 °C. The enzyme retained its full activity after incubating in a pH range of 5.0-10.0 for 10 min at 80 °C. The temperature dependence of the kinetic parameters for this enzyme was examined at 37-70 °C. A decrease in K(m)s for UDP-glucose and NAD was observed with decreasing temperature. This resulted in the enzyme still retaining high catalytic efficiency (V(max)/K(m)) for the substrate and cofactor, even at 37 °C. These characteristics make the enzyme potentially useful for its application at a much lower temperature such as 37 °C than the optimum growth temperature of 100 °C for P. islandicum.
authors: Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, University of Fukui, Fukui, Japan.
authors: Takenori
authors: T
authors: Satomura
authors: Kaori
authors: K
authors: Kusumi
authors: Toshihisa
authors: T
authors: Ohshima
authors: Haruhiko
authors: H
authors: Sakuraba
mesh_terms: D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D041543:Pyrobaculum / Q000201:enzymology* / Q000235:genetics; D013696:Temperature; D014533:Uridine Diphosphate Glucose Dehydrogenase / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D014533:Uridine Diphosphate Glucose Dehydrogenase