Merck, T3824-25KU, Tyrosinase from mushroom

Isoelectric point (pI): 4.7-5 pH optimum is 6-7 Molecular weight: 128 kDa by sedimentation velocity diffusion; 133 kDa by light-scattering measurements, and 119.5 kDa by electrophoresis. Tyrosinase is a copper-containing oxidase, which has activity for both catechols and cresol. It is responsible for browning reactions. The enzyme is reported to have two binding sites for aromatic substrates and a different binding site for oxygen-copper. The copper is probably Cu(I), with inactivation involving oxidation to Cu(II) ion.