Comparative Kinetic Characterization of Catalases from Candida boidinii Yeast and Bovine Liver

D. I. Metelitza,^1,2 A. N. Eryomin,¹ I. M. Artzukevich,³ and I. P. Chernikevich³

¹Institute of Bioorganic Chemistry, Academy of Sciences of Belarus, ul. Zhodinskaya 5/2, Minsk, 220141 Belarus; fax: (0172) 63-72-74; E-mail: ibochbel@eco2.iasnet.com

²To whom correspondence should be addressed.

³Institute of Biochemistry, Academy of Sciences of Belarus, Bulvar Leninskogo Komsomola 50, Grodno, 230009 Belarus; fax: (0152) 33-41-21.

Submitted October 17, 1996; revision submitted January 5, 1997.

Catalase with molecular weight 230 ± 2 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 rate 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 k_cat/K_m 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.

KEY WORDS: catalase from C. boidinii, bovine liver catalase, kinetic characteristics, inactivation during reaction, operational stability, inactivation during cyclic process.

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