Unraveling Substrate Specificity and Catalytic Promiscuity of Aspergillus oryzae Catechol Oxidase.Penttinen, L., Rutanen, C., Janis, J., Rouvinen, J., Hakulinen, N.
(2018) Chembiochem 19: 2348-2352
- PubMed: 30204291
- DOI: https://doi.org/10.1002/cbic.201800387
- Primary Citation of Related Structures:
- PubMed Abstract:
Catechol oxidases and tyrosinases are coupled binuclear copper enzymes that oxidize various o-diphenolic compounds to corresponding o-quinones. Tyrosinases have an additional monooxygenation ability to hydroxylate monophenol to o-diphenol. It is still not clear what causes the difference in the catalytic activities. We solved a complex structure of Aspergillus oryzae catechol oxidase with resorcinol bound into the active site. Catalytic activity of A. oryzae catechol oxidase was studied, for the first time, by high-resolution FT-ICR mass spectrometry to shed light on the reaction mechanism. The enzyme was also found to catalyze monooxygenation of small phenolics, which provides a novel perspective for the discussion of differences in the catalytic activity between tyrosinases and catechol oxidases. According to the results, two binding modes for resorcinol are suggested and a reaction mechanism for coupled binuclear copper enzymes is discussed.
Department of Chemistry, University of Eastern Finland, Yliopistokatu 7, 80130, Joensuu, Finland.