tyrosinasen.
/ˈtʌɪərəsɪneɪz//tʌɪˈrɒsɪneɪz/ Biochemistry.
A copper-containing oxygenase found in many plants and animals which catalyses the formation of quinones from phenols and polyphenols (e.g. melanin from tyrosine) by the addition and then the oxidation of hydroxyl groups.
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1896 Jrnl. Royal Microsc. Soc. 430 In the root of the dahlia and beet, as well as in several fungi..M. G. Bertrand finds a hitherto undescribed diastase, to which he gives the name tyrosinase, from its connection with tyrosin.
1904 Proc. Royal Soc. 74 313 An extract can be made from the skins of certain pigmented animals.., which will act upon tyrosin and produce a pigmented substance. This action suggests the presence of a tyrosinase.
1931 E. C. Miller Plant Physiol. xiii. 768 The oxidases of plants that have been studied have been grouped into two main classes according to the substances upon which they act. These are the laccases or phenolases and the tyrosinases.
1974 R. G. S. Bidwell Plant Physiol. vi. 119 Several enzymes that oxidize phenols to quinones are known. Two of the most important are monophenol oxidase (tyrosinase) and polyphenol oxidase (catechol oxidase).
1982 T. I. Diamondstone in T. M. Devlin Textbk. Biochem. xii. 614/2 Melanin is formed from tyrosine via l-dopa as intermediate; however, the enzyme that catalyzes the formation of l-dopa in this pathway is not tyrosine hydroxylase, but a copper-containing oxygenase known as tyrosinase.
This entry has not yet been fully updated (first published 1986; most recently modified version published online June 2018).
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