title: Effect of immobilization on kinetic and thermodynamic characteristics of sulfide oxidase from Arthrobacter species.
abstract: In order to determine the impact of immobilization on biocatalytic efficacy of sulfide oxidase, the kinetic and thermodynamic properties of native and DEAE-cellulose immobilized sulfide oxidase from Arthrobacter species FR-3 were evaluated. Immobilization increased the catalytic efficiency of sulfide oxidase by producing a lower Michaelis-Menten constant (Km) and a higher rate of catalysis (Vmax) at different temperatures. The first-order kinetic analysis of thermal denaturation demonstrated that the values of enthalpy (delta H*d) and entropy (delta S*d) of immobilized sulfide oxidase were lower than the native enzyme, confirming the thermal stabilization of sulfide oxidase by immobilization. The delta H*d and delta S*d of the immobilized enzyme at 35 degrees C were 138.07 kJ/mol and 122.04 J/K/mol, respectively. These results suggest that immobilization made the sulfide oxidase from Arthrobacter sp. FR-3 thermodynamically more efficient for catalysis of sulfide oxidation.
authors: CANMET Materials Technology Laboratory, Natural Resources Canada, Ottawa, Canada. bmohapat@uvic.ca
authors: Bidyut R
authors: BR
authors: Mohapatra
authors: W Douglas
authors: WD
authors: Gould
authors: Orlando
authors: O
authors: Dinardo
authors: Sankara
authors: S
authors: Papavinasam
authors: David W
authors: DW
authors: Koren
authors: R Winston
authors: RW
authors: Revie
mesh_terms: D001173:Arthrobacter / Q000201:enzymology*; D002384:Catalysis; D004789:Enzyme Activation; D004795:Enzyme Stability; D004800:Enzymes, Immobilized; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010084:Oxidation-Reduction; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000737:chemistry / Q000378:metabolism*; D013816:Thermodynamics
chemical_list: D004800:Enzymes, Immobilized; D050862:Oxidoreductases Acting on Sulfur Group Donors; C080499:sulfide oxidase