title: Comparative kinetic characterization of catalases from Candida boidinii yeast and bovine liver.
abstract: Catalase with molecular weight 230 +/- kD was isolated and purified from methylotrophic yeasts Candida boidinii by ion-exchange chromatography. The kinetic characteristics of yeast and bovine liver catalases were compared in the reaction of H2O2 decomposition using a wide range of H2O2 concentrations (up to 0.12 M) and PH (2-10). First order rates constants (k, sec-1) were determined for both enzymes from semi-logarithmic anamorphoses of kinetic curves of H2O2 utilization. Anamorphoses of complete kinetic curves as a function of 1/ln([H2O2]0/[H2O2]t) versus 1/t were used for calculation of the effective rate constants of catalase inactivation during the reaction (k(in), sec-1) and the rate constants of interaction of catalase complex I with the second molecule of H2O2 (k2, M-1.sec-1). The effects of initial catalase concentrations, H2O2, and pH on k, k2, and k(in) were similar for both enzymes. Catalytic constant, k2, and the efficacy expressed as a ratio kcat/Km were 1.87-, 1.45-, and 1.3-fold, respectively, higher for bovine catalase than that of yeast catalase. Operational stability of yeast catalase is 3.5-fold higher than the stability of bovine catalase and much higher during cyclic decomposition of 50 mM H2O2. Enhanced operational stability and inexpensive source of its preparation open prospects for practical applications of yeast catalase for co-immobilization with superoxide dismutase on non-toxic carriers.
authors.affiliation: Institute of Bioorganic Chemistry, Academy of Sciences of Belarus. ibochbel@eco2.iasnet.com
authors.forename: D I
authors.initials: DI
authors.lastname: Metelitza
authors.forename: A N
authors.initials: AN
authors.lastname: Eryomin
authors.forename: I M
authors.initials: IM
authors.lastname: Artzukevich
authors.forename: I P
authors.initials: IP
authors.lastname: Chernikevich
mesh_terms: D000818:Animals; D002175:Candida / Q000201:enzymology*; D002374:Catalase / Q000302:isolation & purification / Q000378:metabolism*; D002417:Cattle; D002852:Chromatography, Ion Exchange; D004795:Enzyme Stability; D006861:Hydrogen Peroxide / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D013053:Spectrophotometry
chemical_list: D006861:Hydrogen Peroxide; D002374:Catalase