Title: Tyrosinase
CAS Registry Number: 9002-10-2
Literature References: A copper-containing enzyme widely distributed in plants, animals, and man. Catalyzes the hydroxylation of tyrosine in the liver and in melanin-forming cells to 3,4-dihydroxyphenylalanine (dopa). Causes the cut surface of many fruits and plants to darken. The enzyme, as isolated from the common edible mushroom or potato, is characterized by its ability to catalyze aerobic oxidation of both monohydric and o-dihydric phenols. These activities are commonly referred to as cresolase (monophenolase, monophenoloxidase) and catecholase (o-dihydric phenolase) activities. Since monophenolase activity is frequently lost during purification of the enzyme, the name polyphenolase (polyphenoloxidase) is preferred by some workers for prepns which have mainly o-dihydric phenolase activity. Ref: C. R. Dawson, W. B. Tarpley "Copper Oxidases" in J. B. Sumner, K. Myrbäck, The Enzymes vol. II, (Academic Press, New York, 1951) pp 456-483. Prepn from potato peels: Kubowitz, Biochem. Z. 299, 32 (1938). Extraction from mushrooms: Cohen, Lerner, US 2956929 (1960 to Gillette). Separation of a-, b-, g-, and d-tyrosinases of mushroom tyrosinase: Bouchilloux et al., J. Biol. Chem. 238, 1699 (1963). Isoln and properties of crystalline tyrosinase from Neurospora: Fling et al., ibid., p 2045. Isoln and properties of b-tyrosinase: Kumagai et al., J. Biol. Chem. 245, 1767 (1970).
Therap-Cat: Antihypertensive.
Keywords: Antihypertensive.
Tyrosine Tyrothricin Yam, Mexican Yellow AB Yellow OB

Symbols TYR (; CMM8; OCA1A; OCAIA; SHEP3)
External IDs OMIM: 606933 MGI: 98880 HomoloGene: 30969 ChEMBL: 1973 GeneCards: TYR Gene
EC number
RNA expression pattern
PBB GE TYR 206630 at tn.png
More reference expression data
Species Human Mouse
Entrez 7299 22173
Ensembl ENSG00000077498 ENSMUSG00000004651
UniProt P14679 P11344
RefSeq (mRNA) NM_000372 NM_011661
RefSeq (protein) NP_000363 NP_035791
Location (UCSC) Chr 11:
88.91 – 89.03 Mb
Chr 7:
87.43 – 87.49 Mb
PubMed search [1] [2]

In molecular biology, tyrosinase refers to an oxidase, which is the rate-limiting enzyme for controlling the production of melanin. It is mainly involved in two distinct reactions of melanin synthesis; firstly, the hydroxylation of a monophenol and secondly, the conversion of an o-diphenol to the corresponding o-quinone. o-Quinone undergoes several reactions to eventually form melanin.[1] Tyrosinase is a copper-containing enzyme present in plant and animal tissues that catalyzes the production of melanin and other pigments from tyrosine by oxidation, as in the blackening of a peeled or sliced potato exposed to air. It is found inside melanosomes. In humans, the tyrosinase enzyme is encoded by the TYR gene.[2]