title: Characteristics of Psychrophilic Alkaline Phosphatase.
abstract: The phosphatase of a psychrophile (Shewanella sp.) was purified by ammonium sulfate fractionation, followed by sequential column chromatographies. The purified enzyme was electrophoretically homogeneous on native- and SDS-PAGE. Its molecular weight was 41,826 by its amino acid composition. The enzyme had its optimal pH for the activity at 9.8, and a broad substrate specificity to dephosphorylate ATP, pyrophosphate, glycerophosphate, and so on. Its activity was increased by metal ions including Mg(2+), Mn(2+), and Co(2+). The maximal activity was observed at 40°C, and the enzyme at 0°C showed 39% of activity at 40°C. The enzyme, however, tended to lose its activity at 20°C and pH 9.8. These results indicated that purified enzyme was an alkaline phosphatase with characteristics; high catalytic efficiency at low temperature and gradual inactivation at an intermediate temperature.
authors.affiliation: a Laboratory of Biological Chemistry, Department of Biofunctional Chemistry, Faculty of Agriculture, Kobe University.
authors.forename: Y
authors.initials: Y
authors.lastname: Ishida
authors.affiliation: a Laboratory of Biological Chemistry, Department of Biofunctional Chemistry, Faculty of Agriculture, Kobe University.
authors.forename: H
authors.initials: H
authors.lastname: Tsuruta
authors.affiliation: a Laboratory of Biological Chemistry, Department of Biofunctional Chemistry, Faculty of Agriculture, Kobe University.
authors.forename: S T
authors.initials: ST
authors.lastname: Tsuneta
authors.affiliation: a Laboratory of Biological Chemistry, Department of Biofunctional Chemistry, Faculty of Agriculture, Kobe University.
authors.forename: T
authors.initials: T
authors.lastname: Uno
authors.affiliation: b Department of Applied Bioscience, Faculty of Agriculture, Saga University.
authors.forename: K
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: a Laboratory of Biological Chemistry, Department of Biofunctional Chemistry, Faculty of Agriculture, Kobe University.
authors.forename: Y
authors.initials: Y
authors.lastname: Aizono
keywords: alkaline phosphatase; cold enzyme; low-temperature; psychrophilic phosphatase