This is a copper-containing oxidase that functions in the formation of pigments such as melanins and other polyphenolic compounds. Catalyzes the rate-limiting conversions of tyrosine to DOPA, DOPA to DOPA-quinone and possibly 5,6 dihydroxyindole to indole-5'6 quinone (By similarity). Catalyzes the oxidation of 4-methylcatechol (PubMed:16185666, PubMed:19557749). Binds to the surface of hemocytes and is involved in hemocyte melanization (By similarity). L-tyrosine + O2 = H2O + L-dopaquinone 2 L-dopa + O2 = 2 H2O + 2 L-dopaquinone Binds 2 copper ions per subunit. Activated by a cationic detergent cetyl pyridinium chloride (CPC) (PubMed:16185666, PubMed:19557749). Inhibited by phenyl thio-urea (PTU) (PubMed:16185666). Heterodimer. Secreted in the hemolymph. Expressed in hemocytes. Expressed in larvae. Expressed on all days from the fourth through the sixth instar, with the highest expression in the fifth instar. The level varies in the sixth instar with reduced levels observed on the first day, significant on the next day, and diminished levels on the following two days. The maximum level is observed during the active feeding period. Immediately upon microbial challenge with E.coli K-12. Expression increases 2.6-fold 6 hours after the challenge and 10.19-fold after 18 hours. No significant up-regulation in response to injury. Activated by the cleavage of the N-terminal propeptide by PPAE1. Belongs to the tyrosinase family.