Characterization of the catalase of the n-alkane-utilizing yeast Candida tropicalis functionally expressed in Saccharomyces cerevisiae.

Candida tropicalis catalase (CTC) genomic DNA was recombined on a plasmid with the galactose-inducible GAL7 promoter and expressed highly as a heme protein in Saccharomyces cerevisiae as host. The percentage of recombinant CTC (rCTC) in total extractable protein amounted to at least 25%. The rCTC was purified and characterized in terms of subunit mass, behavior in native polyacrylamide gel electrophoresis, absorption spectrum, amino-terminal amino acid sequence, peptide map, specific activity, and Michaelis constant (Km) value for hydrogen peroxide. These properties were similar or identical to those of the purified enzyme from C. tropicalis (CTC). From these results, this system appears suitable for high expression of functional catalase protein having heme.