Heterologous expression and characterization of functional mushroom tyrosinase (AbPPO4).
Pretzler, M., Bijelic, A., Rompel, A.(2017) Sci Rep 7: 1810-1810
- PubMed: 28500345 
- DOI: https://doi.org/10.1038/s41598-017-01813-1
- Primary Citation of Related Structures:  
5M6B - PubMed Abstract: 
Tyrosinases are an ubiquitous group of copper containing metalloenzymes that hydroxylate and oxidize phenolic molecules. In an application context the term 'tyrosinase' usually refers to 'mushroom tyrosinase' consisting of a mixture of isoenzymes and containing a number of enzymatic side-activities. We describe a protocol for the efficient heterologous production of tyrosinase 4 from Agaricus bisporus in Escherichia coli. Applying this procedure a pure preparation of a single isoform of latent tyrosinase can be achieved at a yield of 140 mg per liter of autoinducing culture medium. This recombinant protein possesses the same fold as the enzyme purified from the natural source as evidenced by single crystal X-ray diffraction. The latent enzyme can be activated by limited proteolysis with proteinase K which cleaves the polypeptide chain after K382, only one The latent enzyme can amino acid before the main in-vivo activation site. Latent tyrosinase can be used as obtained and enzymatic activity may be induced in the reaction mixture by the addition of an ionic detergent (e.g. 2 mM SDS). The proteolytically activated mushroom tyrosinase shows >50% of its maximal activity in the range of pH 5 to 10 and accepts a wide range of substrates including mono- and diphenols, flavonols and chalcones.
Organizational Affiliation: 
Universität Wien, Fakultät für Chemie, Institut für Biophysikalische Chemie, Althanstraße 14, 1090, Wien, Austria.