Tyrosinase

Tyrosinase (monophenol or o-diphenol, oxygen oxidoreductase, syn.polyphenol oxidase), a multifunctional membrane bound type-3 copper-containing glycoprotein is located in the membrane of the melanosome.Tyrosinase is also catalyzing the process of neuromelanin production in which the oxidation of dopamine produces dopaquinones. Tyrosinase is also catalyzing the process of neuromelanin production in which the oxidation of dopamine produces dopaquinones. Excessive production of dopaquinones results in neuronal damage and cell death. In animals, the tyrosinase family of proteins is composed of three members, the authentic tyrosinase and two other related proteins, named Trp1 and Trp2. 
The three members of the family show a common architecture of the tridimensional structure, and the three proteins are anchored to the melanosomal membrane through a C-terminal fragment. The intramelanosomal domains of the three proteins are similar in length, and they contain a binuclear metal ion-binding motif with six conserved His. However, the C-terminal tails show very low homology, and they were used to generate specific antibodies, PEP1, PEP7 and PEP8 for Trp1, tyrosinase and Trp2, respectively. The specific reactivity of those antibodies against each C-tail allowed the differentiation, characterization and quantitation of the three proteins. Tyrosinase might play a significant role in neuromelanin formation in the human brain and responsible for the neurodegeneration associated with Parkinson’s disease and Huntington’s diseases.

References

1.Pillaiyar T, et al. J Enzyme Inhib Med Chem. 2017;32(1):403–425.
2.Solano F. Int J Mol Sci. 2018;19(2):633.