Purification and properties of catechol 1,2-oxygenase from Trichosporon cutaneum.

Abstract

A highly purified preparation of catechol 1,2‐oxygenase was obtained from a strain of Trichosporon cutaneum, isolated from soil as a predominant phenol utilizing yeast. The purified active enzyme was homogeneous upon polyacrylamide gel electrophoresis. The enzyme was gradually inactivated upon storage. The inactivation was followed by the appearance of a second, electrophoretically distinct band. The active enzyme is red, the inactive form is colourless. Its molecular weight is 109000 as determined by gel filtration; pH optimum 8.2. The Michaelis constants are 5.9 μM for catechol and 81 μM for oxygen. There is no cofactor requirement for activity. The enzyme is sensitive to iron chelating agents, reducing agents and quinones. The enzyme has a broad substrate specificity: besides catechol it is able to cleave hydroxyl‐ and methyl‐substituted catechols. Several catechol derivatives inhibit the enzyme activity towards catechol.