Tyrosinase

Tyrosinase is a copper-containing enzyme that catalyzes the oxidation of tyrosine and related compounds in melanin synthesis. It helps initiate the production of pigments in animals, fungi, and plants.

Tyrosine: Tyrosine is an amino acid used to build proteins and as a precursor for several biological molecules. It is the starting substrate tyrosinase oxidizes during melanin synthesis.
Melanin: Melanin is a family of pigments that absorb light and contribute to coloration in organisms. Tyrosinase-dependent reactions generate precursors that become melanin.
Active site: An active site is the region of an enzyme where substrates bind and chemical reactions occur. Tyrosinase's active site positions copper ions and substrates for oxidation.
Catechol oxidase: Catechol oxidase is a copper enzyme that oxidizes catechols to quinones without hydroxylating monophenols. It shares copper chemistry with tyrosinase but lacks tyrosinase's monophenol hydroxylation activity.
Melanocyte: A melanocyte is a pigment-producing cell that synthesizes melanin and transfers it to surrounding cells. Cellular control of tyrosinase abundance and trafficking shapes melanin production.
L-DOPA: L-DOPA is a molecule produced from tyrosine and used in dopamine synthesis. Tyrosinase forms L-DOPA by hydroxylating tyrosine.
Skin pigmentation: Skin pigmentation is coloration produced largely by melanin in the skin. Tyrosinase activity in melanocytes helps determine the amount of pigment produced.
Type 3 copper protein: A type 3 copper protein contains a pair of copper ions coordinated to oxygen-binding ligands. Tyrosinase shares this paired-copper architecture with related oxygen-activating proteins.
Laccase: Laccase is a multicopper oxidase that oxidizes diverse substrates while reducing oxygen to water. It can oxidize phenolic compounds, but uses a different copper arrangement and reaction cycle.
Melanosome: A melanosome is a specialized organelle in which melanocytes synthesize and store melanin. Tyrosinase must be delivered into melanosomes, where pigment synthesis occurs.

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