Properties of Catalase Purified from Whole Cells and Peroxisomes of n‐Alkane‐Grown Candida tropicalis

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Abstract
Peroxisomes appear profusely, in harmony with a marked enhancement of catalase activity level, in yeast cells growing on n-alkanes or higher fatty acids as the sole C source. Catalase (H2O2:H2O2 oxidoreductase, EC 1.11.1.6) was purified to homogeneity from the crude extract and from the peroxisome-containing particulate fraction of alkane-grown C. tropicalis cells. The purified enzyme from each source was a similar protein of MW 210,000 composed of 4 identical subunits of MW 54,000, a kind of homotetramer. The enzyme contained 1 molecule of heme per subunit, giving the absorption spectrum characteristic of hemoprotein. .beta.-(3,4-Dihydroxyphenyl)-L-alanine served as a substrate for the peroxidatic reaction by the enzyme. Ouchterlony double-diffusion analysis and immunochemical titration with rabbit antiserum against peroxisomal catalase of n-alkane-grown C. tropicalis indicated that cytoplasmic catalase of the yeast is immunologically indistinguishable with peroxisomal catalase.