Recombinant Tyrosinase from Polyporus arcularius: Overproduction in Escherichia coli, Characterization, and Use in a Study of Aurones as Tyrosinase Effectors.

Tyrosinases act in the development of organoleptic properties of tea, raisins, etc., but also cause unwanted browning of fruits, vegetables, and mushrooms. The tyrosinase from Agaricus bisporus has been used as a model to study tyrosinase inhibitors, which are also indispensable in the treatment of skin pigmentation disorders. However, this model has disadvantages such as side enzyme activities and the presence of multiple isoenzymes. Therefore, we aimed to introduce a new tyrosinase model. The pro-tyrosinase from Polyporus arcularius was overproduced in Escherichia coli. Trypsin digestion led to a cleavage after R388 and hence enzyme activation. The tyrosinase was a homodimer and transformed L-DOPA and tert-butylcatechol preferentially. Various aurons were examined as effectors of this enzyme. 2'- and 3'-hydroxyaurones acted as its activators and 2',4'-dihydroxyaurone as an inhibitor, whereas 4'-hydroxyaurones were its substrates. The enzyme is a promising model for tyrosinase effector studies, being a single isoenzyme and void of side enzyme activities.