Tyrosinases (sometimes referred to as polyphenol oxidases, monophenol
monoxygenases, catechol oxidases, cre-solases, or catecholases) are well known for their role in producing melanin in vertebrates.
monooxygenase, polyphenoloxidase, catechol oxidase, and oxidoreductase), a copper-containing enzyme that induces formation of catecholamine quinone derivatives by its oxidase activity, makes a point since it has been demonstrated to cause a neuronal toxicity through oxidation of cytosolic excess dopamine in PD .
Tyrosinase (EC 126.96.36.199), a coppercontaining enzyme that is crucial for melanin production , oxidizes monophenol
(tyrosine) to odiphenol L-DOPA and subsequently to o-quinone dopachrome, which then undergoes chemical and enzymatic reactions to yield melanin .
dihydroxyphenyl alanine; EC 188.8.131.52) is a copper containing metallo enzyme which catalyzes the oxidation of phenols, the ortho hydroxylation of monophenols
to Odiphenols (monophenolase activity), and the oxidation of Oquinones (diphenolase activity).
PO possesses both monophenol
monooxygenase activity (EC 184.108.40.206, tyrosine, dihydroxyphenylalanine, oxygen, and oxidoreductase) and o-diphenoloxidase activity (EC 220.127.116.11, o-diphenol, oxygen, and oxidoreductase) [7, 8].
nature of betanin and reducing intermediates during the oxidation process may confer to the molecule a higher H-atom or electron donation potential.
It can catalyze 2 reactions through hydroxylation of monophenol
to o-diphenol and by oxidation of o-diphenol into the corresponding o-quinone .
Tudela, "Tyrosinase kinetics: discrimination between two models to explain the oxidation mechanism of monophenol
and diphenol substrates," The International Journal of Biochemistry & Cell Biology, vol.
The construction of an IQA producing bacterial platform therefore requires the use of Ralstonia solanacearum tyrosinase (TYR; EC 18.104.22.168, monophenol
, L-DOPA: oxygen oxidoreductase) to produce L-DOPA from L-tyrosine.
The manufacturing process of the lignophenol developed by Funaoka (47), (48) is generally called "the phase-separation conversion method." Some monophenol
derivatives including [rho]-cresol are applicable to the conversion method.
This oxidase catalyzes two distinct reactions of melanin synthesis, the hydroxylation of a monophenol
and the conversion of an o-diphenol to the corresponding oquinone .
, polyphenol oxidase; EC 22.214.171.124) catalyzes the hydroxylation of L-tyrosine to 3,4-dihydroxyphenyalalanine (L-DOPA) and the subsequent oxidation of L-DOPA to dopaquinone (Fenoll et al., 2002).