1.14.18.1: tyrosinase
This is an abbreviated version!
For detailed information about tyrosinase, go to the full flat file.
Word Map on EC 1.14.18.1
-
1.14.18.1
-
melanin
-
melanoma
-
melanocyte
-
melanogenesis
-
melanosomes
-
cosmetic
-
microphthalmia-associated
-
hyperpigmentation
-
melanogenic
-
catechols
-
polyphenols
-
kojic
-
copper
-
albinism
-
whitening
-
hair
-
keratinocytes
-
albino
-
flavonoid
-
biosensors
-
o-quinone
-
amperometric
-
phytochemical
-
pigmentary
-
vitiligo
-
tautomerase
-
laccase
-
abts
-
alpha-msh
-
melanization
-
depigmentation
-
hydroquinone
-
electrode
-
melanocortins
-
2,2-diphenyl-1-picrylhydrazyl
-
copper-binding
-
polyphenoloxidase
-
frap
-
biotechnology
-
agriculture
-
pharmacology
-
hla-a2
-
nutrition
-
1,1-diphenyl-2-picrylhydrazyl
-
food industry
-
hemocyanins
-
environmental protection
-
l-3,4-dihydroxyphenylalanine
-
crest-derived
-
drug development
-
microphthalmia
-
medicine
-
agaricus
-
butyrylcholinesterase
-
melanoma-associated
-
copper-containing
-
decolor
-
bisporus
- 1.14.18.1
- melanin
- melanoma
- melanocyte
-
melanogenesis
- melanosomes
-
cosmetic
-
microphthalmia-associated
- hyperpigmentation
-
melanogenic
- catechols
- polyphenols
-
kojic
- copper
- albinism
-
whitening
- hair
-
keratinocytes
-
albino
- flavonoid
-
biosensors
- o-quinone
-
amperometric
-
phytochemical
-
pigmentary
- vitiligo
-
tautomerase
- laccase
- abts
- alpha-msh
-
melanization
-
depigmentation
- hydroquinone
-
electrode
-
melanocortins
-
2,2-diphenyl-1-picrylhydrazyl
-
copper-binding
- polyphenoloxidase
-
frap
- biotechnology
- agriculture
- pharmacology
-
hla-a2
- nutrition
-
1,1-diphenyl-2-picrylhydrazyl
- food industry
- hemocyanins
- environmental protection
- l-3,4-dihydroxyphenylalanine
-
crest-derived
- drug development
- microphthalmia
- medicine
- agaricus
- butyrylcholinesterase
-
melanoma-associated
-
copper-containing
-
decolor
- bisporus
Reaction
2 L-dopa
+
Synonyms
AbPPO1, AbPPO4, AbTYR, aurone synthase, catalase-phenol oxidase, catechol oxidase, catecholase, CATPO, chlorogenic acid oxidase, chlorogenic oxidase, cresolase, cresolase/monophenolase, CsPPO, CZA14Tyr, deoxy-tyrosinase, dihydroxy-L-phenylalanine:oxygen oxidoreductase, Diphenol oxidase, diphenolase, dopa oxidase, EC 1.10.3.1, EC 1.14.17.2, Hc-derived phenoloxidase, Hc-phenoloxidase, HcPO, HdPO, hemocyanin-derived phenoloxidase, jrPPO1, jrTYR, L-DOPA monophenolase, L-DOPA oxidase, L-DOPA:oxygen oxidoreductase, L-tyrosine hydroxylase, MdPPO1, melC2, MelC2 tyrosinase, met-tyrosinase, monophenol dihydroxyphenylalanine:oxygen oxidoreductase, monophenol monooxidase, monophenol monooxygenase, monophenol monoxygenase, monophenol oxidase, monophenol oxygen oxidoreductase, monophenol, 3,4-dihydroxy L-phenylalanine (L-DOPA):oxygen oxidoreductase, monophenol, dihydroxy-L-phenylalanine oxygen oxidoreductase, monophenol, dihydroxy-L-phenylalanine:oxygen oxidoreductase, monophenol, dihydroxyphenylalanine:oxygen oxidoreductase, monophenol, L-Dopa: oxidoreductase, monophenol, L-DOPA: oxygen oxidoreductase, monophenol, o-diphenol: oxygen oxidoreductase, monophenol, o-diphenol:O2 oxidoreductase, monophenol, o-diphenol:oxygen oxido-reductase, monophenol, o-diphenol:oxygen oxidoreductase, monophenol, polyphenol oxidase, monophenol: dioxygen oxidoreductases, hydroxylating, monophenolase, monphenol mono-oxygenase, More, mTyr, murine tyrosinase, mushroom tyrosinase, mushroom tyrosine, N-acetyl-6-hydroxytryptophan oxidase, o-diphenol oxidase, o-diphenol oxidoreductase, o-diphenol oxygen oxidoreductase, o-diphenol: O2 oxidoreductase, o-diphenol: oxidoreductase, o-diphenol:O2 oxidoreductase, o-diphenol:oxygen oxidoreductase, o-diphenolase, OCA1, Orf13, oxygen oxidoreductase, phenol oxidase, phenol oxidases, phenolase, phenoloxidase, PO, polyaromatic oxidase, polyphenol oxidase, polyphenol oxidase 3, polyphenol oxidase 4, polyphenol oxidase B, polyphenolase, polyphenoloxidase, PotPPO, PPO, PPO 3, PPO B, PPO1, PPO2, PPO3, pro-PO III, prophenoloxidase III, pyrocatechol oxidase, SPRTyr, ST94, ST94t, tryosinase, tryrosinase, TY, tyr, TYR1, TYR2, tyrA, TyrBm, tyrosinase, tyrosinase 2, tyrosinase 4, tyrosinase diphenolase, tyrosine-dopa oxidase
ECTree
1.14.18.1 tyrosinaseAdvanced search results
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results (Substrates Products
Substrates Products on EC 1.14.18.1 - tyrosinase
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SUBSTRATE 
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
(1R,3R,4S,5R)-3-[[(2E)-3-(3,4-dihydroxyphenyl)prop-2-enoyl]oxy]-1,4,5-trihydroxycyclohexanecarboxylic acid + O2
(1R,3R,4S,5R)-3-[[(2E)-3-(3,4-dioxocyclohexa-1,5-dien-1-yl)prop-2-enoyl]oxy]-1,4,5-trihydroxycyclohexanecarboxylic acid + H2O
-
-
-
-
?
(1S,3R,4S,5R)-4-[[(2E)-3-(3,4-dihydroxyphenyl)prop-2-enoyl]oxy]-1,3,5-trihydroxycyclohexanecarboxylic acid + O2
(1S,3R,4S,5R)-4-[[(2E)-3-(3,4-dioxocyclohexa-1,5-dien-1-yl)prop-2-enoyl]oxy]-1,3,5-trihydroxycyclohexanecarboxylic acid + H2O
-
-
-
-
?
(R)-dopaxanthin + dehydroascorbic acid + O2
(R)-dopaxanthin quinone + L-ascorbic acid + H2O
(R)-tyrosine-betaxanthin + L-DOPA + O2
(R)-dopaxanthin + dopaquinone + H2O
-
i.e. (R)-portulacaxanthin II, the activity of the enzyme is not restricted to betaxanthins derived from (S)-amino acids
(R)-dopaxanthin is a pigment, quantitative product analysis
-
?
2 2',3,4,4',6'-pentahydroxychalcone + O2
bracteatin + 2 H2O
-
-
-
?
2',4',6',4-tetrahydroxychalcone + O2
aureusidin + H2O
-
-
-
?
2-caffeoylisocitric acid + O2
?
-
i.e., E-3-carboxy-2-(3-(3,4-dihydroxyphenyl)prop-2-enoyloxy)pentanedioic acid
-
-
?
2-caffeoylisocitric acid 6-methyl ester + O2
?
-
i.e, E-2-(3-(3,4-dihydroxyphenyl)prop-2-enoyloxy)-3-(methoxycarbonyl)pentanedioic acid
-
-
?
2-hydroxy-1-[[(2E)-3-(4-hydroxy-3-methoxyphenyl)prop-2-enoyl]oxy]propane-1,2,3-tricarboxylic acid + O2
3-C-carboxy-2-deoxy-4-O-[(2E)-3-(3-methoxy-4-oxocyclohexa-1,5-dien-1-yl)prop-2-enoyl]pentaric acid + H2O
-
-
-
-
?
2-methylresorcinol + O2
?
-
acts as enzyme substrate and inhibitor, low activity
-
-
?
2-O-caffeoylthreonic acid + O2
?
-
i.e., E-2-(3-(3,4-dihydroxyphenyl)prop-2-enoyloxy)-3,4-dihydroxybutanoic acid
-
-
?
2-[[(2E)-3-(3,4-dihydroxyphenyl)prop-2-enoyl]oxy]-3,4-dihydroxybutanoic acid + O2
2-[[(2E)-3-(3,4-dioxocyclohexa-1,5-dien-1-yl)prop-2-enoyl]oxy]-3,4-dihydroxybutanoic acid + H2O
-
-
-
-
?
3'-hydroxy-larreatricin + O2
3,3'-dihydroxylarreatricin
3-hydroxylation
-
-
?
3,4-dihydroxybenzoic acid + 1/2 O2
(3,4-dioxocyclohexa-1,5-dien-1-yl)acetic acid + H2O
-
isoenzymes 1-3, 22%, 13%, and 13% of L-dopa activity respectively
-
?
3,4-dihydroxymandelic acid + O2
?
-
9% of the activity with L-dopa
-
-
?
3,4-dihydroxyphenyl propionic acid + O2
2-(3,4-dioxocyclohexa-1,5-dien-1-yl)propionic acid + H2O
-
-
-
-
r
3,4-dihydroxyphenylacetic acid + 1/2 O2
(3,4-dioxocyclohexa-1,5-dien-1-yl)acetic acid + H2O
-
DHPAA
-
-
?
3,4-dihydroxyphenylethanol + O2
2-(3,4-dioxocyclohexa-1,5-dien-1-yl)ethanol + H2O
-
-
-
-
r
3,4-dihydroxyphenylglycol + O2
2-(3,4-dioxocyclohexa-1,5-dien-1-yl)glycol + H2O
-
-
-
-
r
3,4-dihydroxyphenylpropionic acid + 1/2 O2
3-(3,4-dioxocyclohexa-1,5-dien-1-yl)propanoic acid + H2O
-
DHPPA
-
-
?
3,4-dihydroxyphenylpropionic acid + O2
3-(3,4-dioxocyclohexa-1,5-dien-1-yl)propionic acid
-
-
-
?
3-(3,4-dihydroxyphenyl) propionic acid + 1/2 O2
3-(3,4-dihydroxyphenyl)propionic acid + H2O
-
-
-
?
3-(3,5-dihydroxyphenyl)-1-propanoic acid + O2
?
low activity
-
-
?
3-(4-hydroxyphenyl)propionic acid + 1/2 O2
3-(3,4-dihydroxyphenyl)propionic acid + H2O
-
-
-
?
3-chlorophenol + O2
4-chloro-1,2-quinone + H2O
-
20% of 3-chlorophenol is oxidized after 2 h by tyrosinase
4-chloro-1,2-quinone subsequently undergoes a nucleophilic substitution reaction at the chlorine atom by excess phenol to give the corresponding phenol-quinone adduct 4-(3-chlorophenoxy)cyclohexa-3,5-diene-1,2-dione
-
?
3-hydroxy-larreatricin + O2
3,3'-dihydroxylarreatricin
3'-hydroxylation
-
-
?
3-[2-(3,4-dihydroxyphenyl)ethylaminocarbonyl]-3-methyl-1-(4-acetylphenyl)triazene + O2
(2E)-3-(4-acetylphenyl)-N-[2-(3,4-dioxocyclohexa-1,5-dien-1-yl)ethyl]-1-methyltriaz-2-ene-1-carboxamide + H2O
-
-
-
-
?
3-[2-(3,4-dihydroxyphenyl)ethylaminocarbonyl]-3-methyl-1-(4-ethoxycarbonylphenyl)triazene + O2
ethyl 4-[(1E)-3-[[2-(3,4-dioxocyclohexa-1,5-dien-1-yl)ethyl]carbamoyl]-3-methyltriaz-1-en-1-yl]benzoate + H2O
-
-
-
-
?
3-[2-(3,4-dihydroxyphenyl)ethylaminocarbonyl]-3-methyl-1-(4-tolyl)triazene + O2
(2E)-N-[2-(3,4-dioxocyclohexa-1,5-dien-1-yl)ethyl]-1-methyl-3-(4-methylphenyl)triaz-2-ene-1-carboxamide + H2O
-
-
-
-
?
3-[2-(4-hydroxyphenyl)ethylaminocarbonyl]-3-methyl-1-(4-acetylphenyl)triazene + O2
(2E)-3-(4-acetylphenyl)-1-methyl-N-[2-(4-oxocyclohexa-1,5-dien-1-yl)ethyl]triaz-2-ene-1-carboxamide + H2O
-
-
-
-
?
3-[2-(4-hydroxyphenyl)ethylaminocarbonyl]-3-methyl-1-(4-cyanophenyl)triazene + O2
(2E)-3-(4-cyanophenyl)-1-methyl-N-[2-(4-oxocyclohexa-1,5-dien-1-yl)ethyl]triaz-2-ene-1-carboxamide + H2O
-
-
-
-
?
3-[2-(4-hydroxyphenyl)ethylaminocarbonyl]-3-methyl-1-(4-ethoxycarbonylphenyl)triazene + O2
ethyl 4-[(1E)-3-methyl-3-[[2-(4-oxocyclohexa-1,5-dien-1-yl)ethyl]carbamoyl]triaz-1-en-1-yl]benzoate + H2O
-
-
-
-
?
3-[2-(4-hydroxyphenyl)ethylaminocarbonyl]-3-methyl-1-(4-tolyl)triazene + O2
(2E)-1-methyl-3-(4-methylphenyl)-N-[2-(4-oxocyclohexa-1,5-dien-1-yl)ethyl]triaz-2-ene-1-carboxamide + H2O
-
-
-
-
?
4-chlorocatechol + 1/2 O2
4-chlorocyclohexa-3,5-diene-1,2-dione + H2O
-
-
-
-
?
4-ethylcatechol + 1/2 O2
4-ethylcyclohexa-3,5-diene-1,2-dione + H2O
-
-
-
-
?
4-hydroxybenzaldehyde + 1/2 O2
3,4-dihydroxybenzaldehyde + H2O
-
-
-
?
4-hydroxybenzyl alcohol + O2 + AH2
3,4-dihydroxybenzyl alcohol + H2O + A
-
-
-
?
4-hydroxyphenyl propionic acid + O2
3,4-dihydroxyphenyl propionic acid + H2O
-
-
-
-
r
4-methyl catechol + O2
4-methyl-o-benzoquinone + H2O
-
5% of the activity with L-dopa
-
-
?
4-nitrocatechol + 1/2 O2
4-nitrocyclohexa-3,5-diene-1,2-dione + H2O
-
-
-
-
?
4-t-butylphenol + O2 + AH2
4-t-butyl 1,2-benzoquinone + H2O + A
-
-
-
?
4-tert-butylcatechol + 1/2 O2
4-tert-butylcyclohexa-3,5-diene-1,2-dione + H2O
-
-
-
-
?
4-[(4-methylphenyl)azo]-1,2-benzendiol + 1/2 O2
4-[(E)-(4-methylphenyl)diazenyl]cyclohexa-3,5-diene-1,2-dione + H2O
alpha-arbutin + O2
?
-
alpha-arbutin also has a weaker inhibitory effect on the monophenolase activity of the enzyme, molecular docking, overview. The hydroxyl group establishes hydrogen bonds with the peroxide ion and polar contacts with a copper ion as well as with residues H259 and H263. The aromatic ring position cannot be stabilized by Pi-Pi-interactions
-
-
?
catechol + 1/2 O2
o-benzoquinone + H2O
-
PPO from butter lettuce shows a higher affinity to 4-methylcatechol than to catechol
-
-
?
deoxyarbutin + O2
?
oxytyrosinase is able to hydroxylate deoxyarbutin and finishes the catalytic cycle by oxidizing the formed o-diphenol to quinone, while the enzyme becomes deoxytyrosinase, which evolves to oxytyrosinase in the presence of oxygen. deoxyarbutin can alsio act as enzyme inhibitor. This compound is the only one described that does not release o-diphenol after the hydroxylation step. Oxytyrosinase hydroxylates the deoxyarbutin in ortho position of the phenolic hydroxyl group by means of an aromatic electrophilic substitution. As the oxygen orbitals and the copper atoms are not coplanar, but in axial/equatorial position, the concerted oxidation/reduction cannot occur and the release of a copper atom to bind again in coplanar position, enabling the oxidation/reduction or release of the o-diphenol from the active site to the medium. In the case of deoxyarbutin, the o-diphenol formed is repulsed by the water due to its hydrophobicity, and so can bind correctly and be oxidized to a quinone before being released
-
-
?
DL-DOPA + O2
DL-dopaquinone + H2O
-
78% activity compared to L-DOPA
-
-
?
esculetin + 1/2 O2
2H-chromene-2,6,7-trione + H2O
-
demonstration, that esculetin is no inhibitor, but a substrate of mushroom polyphenol oxidase (PPO) and horseradish peroxidase (POD)
-
-
?
gallic acid + 1/2 O2
5-hydroxy-3,4-dioxocyclohexa-1,5-diene-1-carboxylic acid + H2O
-
-
-
-
?
gamma-L-glutaminyl-3,4-dihydroxybenzene + O2
gamma-L-glutaminyl-3,4-benzoquinone + H2O
-
-
-
?
gamma-L-glutaminyl-4-hydroxybenzene + O2 + AH2
gamma-L-glutaminyl-3,4-dihydroxybenzene + H2O + A
-
-
-
?
glycyl-glycyl-L-tyrosine + O2
?
-
3.4fold higher activity compared to Tyr
-
-
?
hydroquinone monomethylether + O2
quinone monomethylether
-
-
-
?
hydroxyhydroquinone + O2
2-hydroxy-p-benzoquinone + H2O
-
the oxidation of hydroxyhydroquinone by O2 catalyzed by tyrosinase occurs simultaneously with the non-enzymatic oxidation of hydroxyhydroquinone at pH 7.0, the identical isosbestic points indicating that there is a stoichiometric transformation from hydroxyhydroquinone to 2-hydroxy p-benzoquinone, a red p-quinone
-
-
?
L-isoproterenol + O2
1-[1-hydroxy-2-(propan-2-ylamino)ethyl]-3,4-dioxocyclohexa-1,5-diene + H2O
-
-
-
-
r
L-tyrosine methyl ester + O2
L-DOPA methyl ester + H2O
-
-
-
?
L-tyrosine methyl ester + O2 + AH2
L-dopa methyl ester + H2O + A
-
-
-
-
?
methyl gallate + O2
methyl 5-hydroxy-3,4-dioxocyclohexa-1,5-diene-1-carboxylate + H2O
-
-
-
-
?
N-acetyldopamine quinone + O2
1,2-dehydro-N-acetyldopamine + H2O
-
enzyme has both o-diphenoloxidase and N-acetyldopamine quinone:N-acetyldopamine quinone methide isomerase activity
-
?
N-beta-alanyldopamine + 1/2 O2
N-beta-alanyldopamine quinone + H2O
-
-
-
?
p-hydroxybenzoic acid + O2
?
-
less than 1% activity compared to L-DOPA
-
-
?
phaselic acid + 1/2 O2
(2S)-2-[[(2E)-3-(3,4-dioxocyclohexa-1,5-dien-1-yl)prop-2-enoyl]oxy]butanedioic acid + H2O
-
-
-
-
?
phloretin + O2
?
-
the compound is a substrate and an inhibitor for tyrosinase
-
-
?
protocatechuic acid + 1/2 O2
3,4-dioxocyclohexa-1,5-diene-1-carboxylic acid + H2O
-
-
-
-
?
protocatechuic aldehyde + 1/2 O2
3,4-dioxocyclohexa-1,5-diene-1-carbaldehyde + H2O
-
-
-
-
?
tert-butylcatechol + 1/2 O2
4-(tert-butyl)benzo-1,2-quinone + H2O
-
hydrophobic substrate
-
-
?
tyrosol + O2
?
-
the compound is a substrate and an inhibitor for tyrosinase
-
-
?
vanillin + O2 + AH2
3,4-dihydroxy-5-methoxybenzaldehyde + H2O + A
-
-
-
-
?
(-)-epicatechin + 1/2 O2
?
-
the major endogenous polyphenol in litchi pericarp
-
-
?
(-)-epicatechin + O2
?
-
119% activity at 2.5 mM substrate concentration
-
-
?
(R)-dopaxanthin + dehydroascorbic acid + O2
(R)-dopaxanthin quinone + L-ascorbic acid + H2O
-
-
-
-
?
(R)-dopaxanthin + dehydroascorbic acid + O2
(R)-dopaxanthin quinone + L-ascorbic acid + H2O
-
(R)-dopaxanthin is a pigment, the reaction rate on the (R)-isomer of dopaxanthin is 1.9fold lower than that for the (S)-isomer
quantitative product analysis
-
?
(R)-dopaxanthin + dehydroascorbic acid + O2
(R)-dopaxanthin quinone + L-ascorbic acid + H2O
-
-
-
-
?
(RS)-catechin + O2
?
-
isoenzymes 1-3, 96, 104, and 168% of activity with L-dopa respectively
-
-
?
2 4-methylcatechol + O2
2 4-methyl-1,2-benzoquinone + 2 H2O
-
-
-
?
2 4-methylcatechol + O2
2 4-methyl-1,2-benzoquinone + 2 H2O
high activity
-
-
?
2 4-methylcatechol + O2
2 4-methyl-1,2-benzoquinone + 2 H2O
-
best substrate
-
-
?
2 catechol + O2
2 1,2-benzoquinone + 2 H2O
-
86% relative activity compared to L-DOPA
-
-
?
2 catechol + O2
2 1,2-benzoquinone + 2 H2O
-
51% activity compared to L-dopa
-
-
?
2 catechol + O2
2 1,2-benzoquinone + 2 H2O
-
85% activity compared to L-dopa
-
-
?
2 catechol + O2
2 1,2-benzoquinone + 2 H2O
-
92% activity compared to L-dopa
-
-
?
2 catechol + O2
2 1,2-benzoquinone + 2 H2O
-
92% activity compared to L-dopa
-
-
?
2 catechol + O2
2 1,2-benzoquinone + 2 H2O
-
the highest oxidase activity is observed against catechol
-
-
?
2 catechol + O2
2 1,2-benzoquinone + 2 H2O
-
10.3% activity compared to L-DOPA
-
-
?
2 catechol + O2
2 1,2-benzoquinone + 2 H2O
high activity
-
-
?
2 catechol + O2
2 1,2-benzoquinone + 2 H2O
-
100% activity at 10 mM substrate concentration
-
-
?
2 L-dopa + O2
2 dopaquinone + 2 H2O
-
-
744014, 744483, 744486, 744488, 744490, 744491, 744495, 744511, 744669, 744671, 744676, 744818, 744819, 745086, 745095, 745130, 745133, 745138, 745139, 745406, 745819, 746193, 746346, 746498
-
-
?
2 L-dopa + O2
2 dopaquinone + 2 H2O
-
best substrate
-
-
?
2 L-dopa + O2
2 dopaquinone + 2 H2O
-
-
-
?
2-O-caffeoylhydroxycitric acid + O2
?
-
i.e., E-3-carboxy-2-(3-(3,4-dihydroxyphenyl)prop-2-enoyloxy)-3-hydroxypentanedioic acid
-
-
?
3,4-dihydroxyphenylacetic acid + O2
?
-
12% of the activity with L-dopa
-
-
?
3,4-dihydroxyphenylacetic acid + O2
?
-
3-methylbenzothyazolinone hydrazone, MBTH, as chromophore coupling agent
-
-
?
4-chlorophenol + O2
4-chloro-1,2-quinone + H2O
-
91% of 4-chlorophenol is oxidized after 2 h by tyrosinase
4-chloro-1,2-quinone subsequently undergoes a nucleophilic substitution reaction at the chlorine atom by excess phenol to give the corresponding phenol-quinone adduct 4-(4-chlorophenoxy)cyclohexa-3,5-diene-1,2-dione
-
?
4-hydroxybenzoic acid + O2 + AH2
3,4-dihydroxybenzoic acid + H2O + A
-
50% of activity with L-dopa
-
?
4-hydroxybenzoic acid + O2 + AH2
3,4-dihydroxybenzoic acid + H2O + A
-
-
-
?
4-hydroxybenzyl alcohol + O2
?
-
the compound is a substrate and an inhibitor for tyrosinase
-
-
?
4-hydroxyphenylpropionic acid + O2
?
-
85% activity compared to 3,4-dihydroxyhydrocinnamic acid
-
-
?
4-methoxyphenol + O2
?
-
40% relative activity compared to L-DOPA, weak monophenolase activity
-
-
?
4-methylcatechol + 1/2 O2
4-methyl-1,2-benzoquinone + H2O
-
oxidation of the substrate with NaIO4 in CHCl3, and [P]CHCl3
-
-
?
4-methylcatechol + 1/2 O2
4-methyl-1,2-benzoquinone + H2O
-
diphenolic substrate
-
-
?
4-methylcatechol + 1/2 O2
4-methyl-1,2-benzoquinone + H2O
-
PPO from butter lettuce shows a higher affinity to 4-methylcatechol than to catechol
-
-
?
4-methylcatechol + 1/2 O2
4-methyl-1,2-benzoquinone + H2O
-
efficient diphenolic substrates for cherry PPO
-
-
?
4-methylcatechol + 1/2 O2
4-methyl-1,2-benzoquinone + H2O
-
best substrate
-
-
?
4-methylcatechol + O2
4-methyl-1,2-benzoquinone + H2O
-
good substrate
-
-
?
4-methylcatechol + O2
4-methyl-1,2-benzoquinone + H2O
good substrate
-
-
?
4-methylcatechol + O2
4-methyl-1,2-benzoquinone + H2O
good substrate
-
-
?
4-methylcatechol + O2
4-methyl-1,2-benzoquinone + H2O
-
highest activity
-
-
?
4-methylcatechol + O2
4-methyl-1,2-benzoquinone + H2O
-
highest activity, 183% activity at 10 mM substrate concentration
-
-
?
4-methylcatechol + O2
4-methyl-o-benzoquinone + H2O
-
-
-
?
4-methylcatechol + O2
4-methyl-o-benzoquinone + H2O
-
-
-
?
4-methylcatechol + O2
4-methyl-o-benzoquinone + H2O
-
catecholase/cresolase activity ratio of 41
-
?
4-methylcatechol + O2
4-methyl-o-benzoquinone + H2O
-
-
-
?
4-methylcatechol + O2
4-methyl-o-benzoquinone + H2O
-
-
-
?
4-methylcatechol + O2
?
-
90% activity compared to 3,4-dihydroxyhydrocinnamic acid
-
-
?
4-tert-butylcatechol + 1/2 O2
4-(tert-butyl)benzo-1,2-quinone + H2O
-
-
-
?
4-[(4-methylphenyl)azo]-1,2-benzendiol + 1/2 O2
4-[(E)-(4-methylphenyl)diazenyl]cyclohexa-3,5-diene-1,2-dione + H2O
-
-
-
-
?
4-[(4-methylphenyl)azo]-1,2-benzendiol + 1/2 O2
4-[(E)-(4-methylphenyl)diazenyl]cyclohexa-3,5-diene-1,2-dione + H2O
-
synthetic substrate
-
-
?
4-[(4-methylphenyl)azo]-phenol + O2 + AH2
4-[(4-methylbenzo)azo]-1,2-benzendiol + H2O + A
-
-
-
-
?
4-[(4-methylphenyl)azo]-phenol + O2 + AH2
4-[(4-methylbenzo)azo]-1,2-benzendiol + H2O + A
-
synthetic substrate
-
-
?
alpha-methyl-DL-tyrosine + O2 + AH2
N-methyl-DL-dopa + H2O + A
-
-
-
-
?
beta-arbutin + O2
?
-
alpha-arbutin also has a weaker inhibitory effect on the monophenolase activity of the enzyme, molecular docking, overview. The hydroxyl group establishes hydrogen bonds with the peroxide ion and polar contacts with a copper ion as well as with residues H259 and H263. The aromatic ring position cannot be stabilized by Pi-Pi-interactions
-
-
?
caffeic acid + 1/2 O2
caffeoyl quinone + H2O
-
17% of activity with L-dopa
-
?
caffeic acid + 1/2 O2
caffeoyl quinone + H2O
-
diphenolic caffeic acid is oxidized relatively fast by all tyrosinases, except only moderately by tyrosinase from Pycnoporus sanguineus
-
-
?
caffeic acid + 1/2 O2
caffeoyl quinone + H2O
-
-
-
?
caffeic acid + O2
?
-
27% activity compared to L-dopa
-
-
?
caffeic acid + O2
caffeoyl quinone + H2O
-
50% activity compared to catechol
-
-
?
caffeic acid + O2
caffeoyl quinone + H2O
-
60.9% activity compared to L-DOPA
-
-
?
caffeic acid + O2
caffeoyl quinone + H2O
-
31% activity at 2.5 mM substrate concentration
-
-
?
caffeic acid + O2
caffeoyl quinone + H2O
-
31% activity at 2.5 mM substrate concentration
-
-
?
catechol + 1/2 O2
1,2-benzoquinone + H2O
-
pyrogallol and catechol are best substrates for catalysis and inactivation
-
-
?
catechol + 1/2 O2
1,2-benzoquinone + H2O
-
24% of the activity with L-dopa
-
-
?
catechol + 1/2 O2
1,2-benzoquinone + H2O
-
-
-
?
catechol + 1/2 O2
1,2-benzoquinone + H2O
-
efficient diphenolic substrates for cherry PPO
-
-
?
catechol + 1/2 O2
1,2-benzoquinone + H2O
-
125% of activity with L-dopa
-
?
catechol + O2
?
-
12% activity compared to 3,4-dihydroxyhydrocinnamic acid
-
-
?
chlorogenic acid + 1/2 O2
chlorogenoquinone + H2O
-
-
-
?
chlorogenic acid + O2
?
-
formation of a highly reactive o-quinone intermediate which then can interact with NH2 groups of lysine, SCH3 groups of methionines and indole rings of tryptophan in nucleophilic addition and in polymerization reactions, the so-called browning and greening reactions
-
-
?
chlorogenic acid + O2
?
-
formation of a highly reactive o-quinone intermediate
-
-
?
chlorogenic acid + O2
?
-
the major polyphenol oxidase substrate is chlorogenic acid
-
-
?
chlorogenic acid + O2
chlorogenoquinone + H2O
-
-
-
?
chlorogenic acid + O2
chlorogenoquinone + H2O
-
108% of activity with L-dopa
-
?
D-catechin + O2
?
-
isoenzymes 1, 2 and 3, 90%, 86% and 188% of L-dopa activity respectively
-
-
?
D-dopa + 1/2 O2
D-dopaquinone + H2O
tyrosinase oxidizes L- and D-forms with similar rate
-
-
?
D-dopa + 1/2 O2
D-dopaquinone + H2O
-
L-forms of dopa and tyrosine are much better substrates than the corresponding D-forms. Because the activity of the tyrosinase on tyrosine is practically nondetectable, no significant differences between the oxidation rates on the D-, DL- and D-forms of tyrosine can be measured for tyrosinase
-
-
?
D-dopa + 1/2 O2
D-dopaquinone + H2O
tyrosinase oxidizes L- and D-forms with similar rate
-
-
?
D-dopa + 1/2 O2
D-dopaquinone + H2O
-
L-forms of dopa and tyrosine are much better substrates than the corresponding D-forms
-
-
?
D-dopa + 1/2 O2
D-dopaquinone + H2O
-
L-forms of dopa and tyrosine are much better substrates than the corresponding D-forms
-
-
?
D-DOPA + O2
D-dopaquinone + H2O
-
34.0% activity compared to L-DOPA
-
-
?
D-tyrosine + O2 + AH2
D-dopa + H2O + A
tyrosinase oxidizes L- and D-forms with similar rate
-
-
?
D-tyrosine + O2 + AH2
D-dopa + H2O + A
-
L-forms of dopa and tyrosine are much better substrates than the corresponding D-forms. Because the activity of the tyrosinase on tyrosine is practically nondetectable, no significant differences between the oxidation rates on the D-, DL- and D-forms of tyrosine can be measured for tyrosinase
-
-
?
D-tyrosine + O2 + AH2
D-dopa + H2O + A
tyrosinase oxidizes L- and D-forms with similar rate
-
-
?
D-tyrosine + O2 + AH2
D-dopa + H2O + A
-
L-forms of dopa and tyrosine are much better substrates than the corresponding D-forms
-
-
?
D-tyrosine + O2 + AH2
D-dopa + H2O + A
-
L-forms of dopa and tyrosine are much better substrates than the corresponding D-forms
-
-
?
DL-dopa + 1/2 O2
DL-dopaquinone + H2O
tyrosinase oxidizes L- and D-forms with similar rate
-
-
?
DL-dopa + 1/2 O2
DL-dopaquinone + H2O
-
L-forms of dopa and tyrosine are much better substrates than the corresponding D-forms. Because the activity of the tyrosinase on tyrosine is practically nondetectable, no significant differences between the oxidation rates on the D-, DL- and D-forms of tyrosine can be measured for tyrosinase
-
-
?
DL-dopa + 1/2 O2
DL-dopaquinone + H2O
tyrosinase oxidizes L- and D-forms with similar rate
-
-
?
DL-dopa + 1/2 O2
DL-dopaquinone + H2O
-
L-forms of dopa and tyrosine are much better substrates than the corresponding D-forms
-
-
?
DL-dopa + 1/2 O2
DL-dopaquinone + H2O
-
L-forms of dopa and tyrosine are much better substrates than the corresponding D-forms
-
-
?
DL-DOPA + O2
dopaquinone + H2O
-
39% activity at 2.5 mM substrate concentration
-
-
?
DL-tyrosine + O2
dopaquinone + H2O
-
44% activity compared to L-dopa
-
-
?
DL-tyrosine + O2
dopaquinone + H2O
-
57% activity compared to L-dopa
-
-
?
DL-tyrosine + O2
dopaquinone + H2O
-
53% activity compared to L-dopa
-
-
?
DL-tyrosine + O2 + AH2
DL-dopa + H2O + A
tyrosinase oxidizes L- and D-forms with similar rate
-
-
?
DL-tyrosine + O2 + AH2
DL-dopa + H2O + A
-
L-forms of dopa and tyrosine are much better substrates than the corresponding D-forms. Because the activity of the tyrosinase on tyrosine is practically nondetectable, no significant differences between the oxidation rates on the D-, DL- and D-forms of tyrosine can be measured for tyrosinase
-
-
?
DL-tyrosine + O2 + AH2
DL-dopa + H2O + A
tyrosinase oxidizes L- and D-forms with similar rate
-
-
?
DL-tyrosine + O2 + AH2
DL-dopa + H2O + A
-
L-forms of dopa and tyrosine are much better substrates than the corresponding D-forms
-
-
?
DL-tyrosine + O2 + AH2
DL-dopa + H2O + A
-
L-forms of dopa and tyrosine are much better substrates than the corresponding D-forms
-
-
?
dopamine + 1/2 O2
dopamine quinone + H2O
-
-
-
-
?
dopamine + 1/2 O2
dopamine quinone + H2O
-
96% of the activity with L-dopa
-
-
?
dopamine + 1/2 O2
dopamine quinone + H2O
-
preferred substrates in terms of affinity in descending order: N-beta-alanyldopamine, dopamine, N-acetyldopamine, norepinephrine, epinephrine, dopa
-
?
dopamine + 1/2 O2
dopamine quinone + H2O
-
hydrophilic substrate
-
-
?
ferulic acid + O2 + AH2
(2E)-3-(3,4-dihydroxy-5-methoxyphenyl)prop-2-enoic acid + H2O + A
-
-
-
-
?
ferulic acid + O2 + AH2
(2E)-3-(3,4-dihydroxy-5-methoxyphenyl)prop-2-enoic acid + H2O + A
-
-
-
-
?
ferulic acid + O2 + AH2
(2E)-3-(3,4-dihydroxy-5-methoxyphenyl)prop-2-enoic acid + H2O + A
-
-
-
-
?
L-3,4-dihydroxyphenylalanine + 1/2 O2
L-dopaquinone + H2O
-
individually grafted onto a novel CSG1.0 membrane as a ligand
-
-
?
L-3,4-dihydroxyphenylalanine + 1/2 O2
L-dopaquinone + H2O
-
-
-
-
?
L-3,4-dihydroxyphenylalanine + 1/2 O2
L-dopaquinone + H2O
-
-
-
-
?
L-dopa + 1/2 O2
L-dopaquinone + H2O
-
-
676133, 685452, 685515, 685530, 685671, 686065, 686532, 687260, 687948, 688037, 688064, 689106, 689383, 689439, 689441, 689702
-
-
?
L-dopa + 1/2 O2
L-dopaquinone + H2O
tyrosinase oxidizes L- and D-forms with similar rate
-
-
?
L-dopa + 1/2 O2
L-dopaquinone + H2O
-
L-forms of dopa and tyrosine are much better substrates than the corresponding D-forms. Because the activity of the tyrosinase on tyrosine is practically nondetectable, no significant differences between the oxidation rates on the D-, DL- and D-forms of tyrosine can be measured for tyrosinase
-
-
?
L-dopa + 1/2 O2
L-dopaquinone + H2O
-
1.5fold higher affinity for L-tyrosine compared to L-dopa
-
-
?
L-dopa + 1/2 O2
L-dopaquinone + H2O
-
1.5fold higher affinity for L-tyrosine compared to L-dopa
-
-
?
L-dopa + 1/2 O2
L-dopaquinone + H2O
tyrosinase oxidizes L- and D-forms with similar rate
-
-
?
L-dopa + 1/2 O2
L-dopaquinone + H2O
-
L-forms of dopa and tyrosine are much better substrates than the corresponding D-forms
-
-
?
L-dopa + 1/2 O2
L-dopaquinone + H2O
-
L-forms of dopa and tyrosine are much better substrates than the corresponding D-forms
-
-
?
L-DOPA + O2
dopaquinone + H2O
-
-
696844, 697659, 697741, 697744, 698040, 698427, 699039, 699403, 699640, 700322, 712534, 712597, 713205, 727168
-
-
?
L-DOPA + O2
dopaquinone + H2O
-
1% activity compared to 3,4-dihydroxyhydrocinnamic acid
-
-
?
L-Dopa + O2
L-dopaquinone + H2O
-
30% activity compared to catechol
-
-
?
L-epicatechin + O2
?
-
isoenzyme 1, 150% of L-dopa activity, isoenzyme 2 and 3, 170% and 175% of activity with L-dopa respectively
-
-
?
L-Tyr + O2 + AH2
L-dopa + H2O + A
-
10% of the activity with L-dopa
-
-
?
L-tyrosine + L-dopa + O2
L-dopa + dopaquinone + H2O
TyrA has a relatively higher affinity to L-DOPA than many other tyrosinases, the monophenol oxidase activity of this enzyme is undetectable when the concentration of L-dopa was lower than 0.01 mM, while the maximum monophenol oxidase activity is detected with 0.05 mM L-DOPA as cosubstrate
-
-
?
L-tyrosine + L-dopa + O2
L-dopa + dopaquinone + H2O
TyrA has a relatively higher affinity to L-DOPA than many other tyrosinases, the monophenol oxidase activity of this enzyme is undetectable when the concentration of L-dopa was lower than 0.01 mM, while the maximum monophenol oxidase activity is detected with 0.05 mM L-DOPA as cosubstrate
-
-
?
L-tyrosine + L-dopa + O2
L-dopa + dopaquinone + H2O
-
-
-
-
?
L-tyrosine + L-dopa + O2
L-dopa + dopaquinone + H2O
-
-
o-dopaquinone is unstable in aqueous solution and rapidly suffers a non-enzymatic cyclization to leukodopachrome
-
?
L-tyrosine + L-dopa + O2
L-dopa + dopaquinone + H2O
-
-
o-dopaquinone is unstable in aqueous solution and rapidly suffers a non-enzymatic cyclization to leukodopachrome
-
?
L-tyrosine + L-dopa + O2
L-dopa + dopaquinone + H2O
-
-
o-dopaquinone is unstable in aqueous solution and rapidly suffers a non-enzymatic cyclization to leukodopachrome
-
?
L-tyrosine + L-dopa + O2
L-dopa + dopaquinone + H2O
-
pathway of melanin biosynthesis, detailed overview
cytotoxicity of L-DOPA
-
?
L-tyrosine + L-dopa + O2
L-dopa + dopaquinone + H2O
-
-
o-dopaquinone is unstable in aqueous solution and rapidly suffers a non-enzymatic cyclization to leukodopachrome
-
?
L-tyrosine + L-dopa + O2
L-dopa + dopaquinone + H2O
-
air saturated 50 mM phosphate buffer, pH 7.0, 30°C
polymerizes to form melanin-like pigments
-
?
L-tyrosine + L-dopa + O2
L-dopa + dopaquinone + H2O
-
-
-
-
?
L-tyrosine + L-dopa + O2
L-dopa + dopaquinone + H2O
-
-
-
-
?
L-tyrosine + L-dopa + O2
L-dopa + dopaquinone + H2O
-
-
o-dopaquinone is unstable in aqueous solution and rapidly suffers a non-enzymatic cyclization to leukodopachrome
-
?
L-tyrosine + L-dopa + O2
L-dopa + dopaquinone + H2O
-
high activity, best substrate
-
-
?
L-tyrosine + O2
dopaquinone + H2O
-
-
-
-
?
L-tyrosine + O2
dopaquinone + H2O
-
6% activity compared to 3,4-dihydroxyhydrocinnamic acid
-
-
?
L-tyrosine + O2
L-DOPA + H2O
-
-
-
-
?
L-tyrosine + O2
L-DOPA + H2O
-
2% relative activity compared to L-DOPA, weak monophenolase activity
-
-
?
L-tyrosine + O2
L-DOPA + H2O
-
very low activity, 6% activity at 2.5 mM substrate concentration
-
-
?
L-tyrosine + O2 + AH2
L-3,4-dihydroxyphenylalanine + H2O + A
-
individually grafted onto a novel CSG1.0 membrane as a ligand
-
-
?
L-tyrosine + O2 + AH2
L-3,4-dihydroxyphenylalanine + H2O + A
-
enzyme initiates the formation of pigmentation, absence leads to forms of albinism
-
-
?
L-tyrosine + O2 + AH2
L-3,4-dihydroxyphenylalanine + H2O + A
-
rate-limiting enzyme in melanin biosynthesis
-
-
?
L-tyrosine + O2 + AH2
L-dopa + H2O + A
-
-
685452, 685458, 685461, 685462, 685668, 685671, 687154, 687948, 687996, 688064, 689064, 689118, 689413, 689702
-
-
?
L-tyrosine + O2 + AH2
L-dopa + H2O + A
tyrosinase oxidizes L- and D-forms with similar rate
-
-
?
L-tyrosine + O2 + AH2
L-dopa + H2O + A
radioactive substrate L-[3,5-3H]-tyrosine, specific activity 50 Ci/mmol
-
-
?
L-tyrosine + O2 + AH2
L-dopa + H2O + A
-
1.5fold higher affinity for L-tyrosine compared to L-dopa
-
-
?
L-tyrosine + O2 + AH2
L-dopa + H2O + A
-
1.5fold higher affinity for L-tyrosine compared to L-dopa
-
-
?
L-tyrosine + O2 + AH2
L-dopa + H2O + A
tyrosinase oxidizes L- and D-forms with similar rate
-
-
?
L-tyrosine + O2 + AH2
L-dopa + H2O + A
-
10% of activity with L-dopa
-
?
L-tyrosine + O2 + AH2
L-dopa + H2O + A
-
L-forms of dopa and tyrosine are much better substrates than the corresponding D-forms
-
-
?
L-tyrosine + O2 + AH2
L-dopa + H2O + A
-
nearly no activity with the D-isomer, 7% of the activity with the L-isomer
-
-
?
L-tyrosine + O2 + AH2
L-dopa + H2O + A
-
L-forms of dopa and tyrosine are much better substrates than the corresponding D-forms
-
-
?
N-acetyldopamine + 1/2 O2
N-acetyldopamine quinone + H2O
-
enzyme has both o-diphenoloxidase and N-acetyldopamine quinone:N-acetyldopamine quinone methide isomerase activity
-
?
o-methoxyphenol + O2 + AH2
1,2-dihydroxy-3-methoxybenzene + H2O + A
-
trivial name guaiacol
-
?
o-methoxyphenol + O2 + AH2
1,2-dihydroxy-3-methoxybenzene + H2O + A
-
trivial name guaiacol
-
?
o-methoxyphenol + O2 + AH2
1,2-dihydroxy-3-methoxybenzene + H2O + A
-
trivial name guaiacol
-
?
o-methoxyphenol + O2 + AH2
1,2-dihydroxy-3-methoxybenzene + H2O + A
-
trivial name guaiacol
-
?
o-methoxyphenol + O2 + AH2
1,2-dihydroxy-3-methoxybenzene + H2O + A
-
trivial name guaiacol
-
?
o-methoxyphenol + O2 + AH2
1,2-dihydroxy-3-methoxybenzene + H2O + A
-
trivial name guaiacol
-
?
orcin + O2
?
-
isoenzymes 1-3, 41%, 33%, and 25% of activity with L-dopa respectively
-
-
?
oxyresveratrol + O2
?
-
tyrosinase hydroxylates the oxyresveratrol to an o-diphenol and oxidizes the latter to an o-quinone, which finally isomerizes to p-quinone. For these reactions to take place the presence of the Eox (oxy-tyrosinase) form is necessary, analysis of the catalytic mechanism, overview. The compound can also act as inhibitor of tyrosinase
-
-
?
p-coumaric acid + O2
caffeic acid + H2O
-
6.1% activity compared to L-DOPA
-
-
?
p-coumaric acid + O2 + AH2
caffeic acid + H2O + A
-
artificial electron donors: NADH, dimethyltetrahydropteridine and ascorbic acid
-
?
p-coumaric acid + O2 + AH2
caffeic acid + H2O + A
-
p-coumaric acid is rapidly oxidized only by tyrosinase from Trichoderma reesei
-
-
?
p-cresol + O2
4-methylpyrocatechol + H2O
relatively well oxidized
-
-
?
p-cresol + O2 + AH2
4-methylpyrocatechol + H2O + A
-
relatively well oxidized by tyrosinase
-
-
?
p-tyrosol + O2 + AH2
2-(3,4-dihydroxyphenyl)ethanol + H2O + A
-
-
-
?
p-tyrosol + O2 + AH2
2-(3,4-dihydroxyphenyl)ethanol + H2O + A
-
relatively well oxidized by tyrosinase
-
-
?
p-tyrosol + O2 + AH2
2-(3,4-dihydroxyphenyl)ethanol + H2O + A
relatively well oxidized
-
-
?
phenol + O2 + AH2
o-dihydroxybenzene + H2O + A
Emerita asiatica
-
no activity with phenol
-
-
?
phloridzin + O2
?
-
the compound is a substrate and an inhibitor for tyrosinase
-
-
?
pyrogallol + 1/2 O2
?
-
pyrogallol and catechol are best substrates for catalysis and inactivation
-
-
?
pyrogallol + O2
?
-
isoenzymes 1-3, 210%, 263%, and 225% of activity with L-dopa respectively
-
-
?
resorcinol + O2
?
-
isoenzymes 1-3, 96%, 129%, and 100% of activity with L-dopa respectively
-
-
?
tyramine + O2
4-(2-aminoethyl)cyclohexa-3,5-diene-1,2-dione + H2O
-
-
-
?
tyramine + O2
4-(2-aminoethyl)cyclohexa-3,5-diene-1,2-dione + H2O
Emerita asiatica
-
no activity with tyramine
-
-
?
tyramine + O2
4-(2-aminoethyl)cyclohexa-3,5-diene-1,2-dione + H2O
-
-
-
?
tyramine + O2
4-(2-aminoethyl)cyclohexa-3,5-diene-1,2-dione + H2O
-
-
-
?
tyramine + O2
4-(2-aminoethyl)cyclohexa-3,5-diene-1,2-dione + H2O
-
-
-
?
tyramine + O2
4-(2-aminoethyl)cyclohexa-3,5-diene-1,2-dione + H2O
-
monophenol
-
-
?
tyramine + O2
4-(2-aminoethyl)cyclohexa-3,5-diene-1,2-dione + H2O
-
-
-
-
?
tyramine + O2
4-(2-aminoethyl)cyclohexa-3,5-diene-1,2-dione + H2O
-
-
-
?
tyramine + O2
4-(2-aminoethyl)cyclohexa-3,5-diene-1,2-dione + H2O
-
isoenzymes 1, 20% of L-dopa activity, isoenzyme2, 13% of activity with L-dopa, isoenzyme 3, 25% of activity with L-dopa
-
?
tyramine + O2
4-(2-aminoethyl)cyclohexa-3,5-diene-1,2-dione + H2O
-
-
-
?
tyramine + O2
4-(2-aminoethyl)cyclohexa-3,5-diene-1,2-dione + H2O
-
-
-
-
?
tyramine + O2
4-(2-aminoethyl)cyclohexa-3,5-diene-1,2-dione + H2O
-
67% of activity with L-dopa
-
?
tyramine + O2
4-(2-aminoethyl)cyclohexa-3,5-diene-1,2-dione + H2O
-
-
-
-
?
tyramine + O2
4-(2-aminoethyl)cyclohexa-3,5-diene-1,2-dione + H2O
-
-
-
-
?
tyrosine + O2
dopaquinone + H2O
-
-
744483, 744486, 744488, 744495, 744511, 744676, 744819, 745130, 745138, 745139, 746193, 746346, 746498
-
-
?
additional information
?
-
-
role of the enzyme in the biosynthetic scheme of betalains, overview
-
-
?
additional information
?
-
-
streospecificity, and monophenolase and diphenolase activities and specificities dependent on conditions, overview
-
-
?
additional information
?
-
-
the enzyme catalyzes the hydroxylation of monophenols to o-diphenols, monophenolase activity EC 1.14.18.1, and the oxidation of the o-diphenols to o-quinones, diphenolase activity EC 1.10.3.1, cross-reaction analysis, overview
-
-
?
additional information
?
-
-
the enzyme catalyzes the hydroxylation of monophenols to o-diphenols, monophenolase activity EC 1.14.18.1, and the oxidation of the o-diphenols to o-quinones, diphenolase activity EC 1.10.3.1, cross-reaction analysis, overview
-
-
?
additional information
?
-
-
tyrosinase is a copper-containing enzyme that catalyzes two distinct reactions of melanin synthesis: the hydroxylation of tyrosine by monophenolase action and the oxidation of 3,4-dihydroxyphenylalanine (L-DOPA) to o-dopaquinone by diphenolase action
-
-
?
additional information
?
-
-
catalyzing the rate-limiting step for melanin biosynthesis
-
-
?
additional information
?
-
accepts both mono- and diphenols as substrates. The hydroxylation ability of the enzyme is also referred to cresolase or monophenolase activity (EC 1.14.18.1), and the oxidation ability to catecholase or diphenolase activity (EC 1.10.3.1). The tyrosinases generally have noticeably lower activity on monophenols than on di- or triphenols. Ferulic acid is not a substrate to any of the tyrosinases. The substrate p-coumaric acid is rapidly oxidized only by tyrosinase from Trichoderma reesei
-
-
?
additional information
?
-
-
the enzyme shows low activity using mono- and triphenols as substrates but much greater activity with the diphenolic substrate
-
-
?
additional information
?
-
-
tyrosinase possesses cresolase/monophenolase and/or catecholase/diphenolase activities
-
-
?
additional information
?
-
mushroom tyrosinase-associated lectin-like protein (MtaL) binds to mature Agaricus bisporus tyrosinase in vivo, binding structure analysis, overview. MtaL undergoes conformational changes upo tyrosinase binding, but the general beta-trefoil fold is conserved, it is essential for carbohydrate interaction in other lectin-like proteins
-
-
?
additional information
?
-
-
mushroom tyrosinase-associated lectin-like protein (MtaL) binds to mature Agaricus bisporus tyrosinase in vivo, binding structure analysis, overview. MtaL undergoes conformational changes upo tyrosinase binding, but the general beta-trefoil fold is conserved, it is essential for carbohydrate interaction in other lectin-like proteins
-
-
?
additional information
?
-
-
the enzyme catalyzes the oxidation of both monophenols (cresolase or monophenolase activity) and o-diphenols (catecholase or diphenolase activity) into reactive o-quinones
-
-
?
additional information
?
-
-
tyrosinase exhibits two mechanisms of oxidation: monooxygenase (EC 1.14.18.1) and oxidase (1.10.3.1) activities. The enzyme is characterised by possessing four discrete oxidation states (deoxy-, oxy-, met- and deact-tyrosinase), detailed overview. The enzyme exhibits a lag period when employed in vitro and it is slowly inactivated by catechol substrates and is rapidly inactivated by resorcinols
-
-
?
additional information
?
-
-
development of a facile fluorescent assay for TYR activity based on dopamine functionalized carbon quantum dots (CQDs-Dopa), method evaluation, overview. Dopamine (Dopa) is covalently bound to CQDs through a simple one-pot hydrothermal method, and the prepared CQDs-Dopa exhibits a fluorescence emission at 499 nm under exciting wavelength at 310 nm with a quantum yield of approximately 2.1%. When TYR is mixed with CODs-Dopa, the dopamine moiety in CQDs-Dopa conjugate is oxidized to O-dopaquinone, and an intra-particle photo-induced electron transfer process consequently occurs between CQDs and O-dopaquinone to quench the fluorescence of CQDs-Dopa. TYR activity can be determined based on the fluorescence quenching degree of CQDs-Dopa. The assay covers two broad linear ranges: 44.4-711.1 U/l and 711.1-2925.4 U/l with detection limit of 17.7 U/l. The proposed fluorescent assay is applied to TYR activity measurement in human serum samples and might be useful for TYR activity assays in clinical applications
-
-
?
additional information
?
-
-
hydroxyhydroquinone autooxidation depends on the pH, overview
-
-
?
additional information
?
-
-
monooxygenation of L-tyrosine gives dopaquinone which undergoes rapid intramolecular cyclization giving cyclodopa. Spontaneous redox exchange with dopaquinone then gives 3,4-dihydroxyphenylalanine (dopa) and dopachrome. Thus, small amounts of monooxygenase activity, initially present, generate dopa from L-tyrosine and this activates more of the met-enzyme. N,N-Dimethyltyramine is oxidized to the corresponding ortho-quinone and undergoes cyclization but is unable to take part in redox exchange, and consequently no activating catechol is formed Rearrangement to a quinomethane prevents formation of an enzymeactivating catechol
-
-
?
additional information
?
-
-
monophenolase and diphenolase activities of mushroom tyrosinase are performed using L-tyrosine and L-DOPA, respectively, by measuring the dopachrome accumulation at 475 nm before immobilization on the chip surface for surface plasmon resonance analysis
-
-
?
additional information
?
-
-
resorcinol and some derivatives, 4-ethylresorcinol, 2-methylresorcinol and 4-methylresorcinol, all act as substrates of tyrosinase if the catalytic cycle is completed with a reductant such as ascorbic acid or an o-diphenol such as 4-tert-butylcatechol. The reaction can also be carried out, adding hydrogen peroxide to the reaction medium. Measurement of the activity of the enzyme after pre-incubation with resorcinol, 4-ethylresorcinol or 4-methylresorcinol points to an apparent loss of activity at short times. If the measurements are extended over longer times, a burst is observed and the enzymatic activity is recovered, demonstrating that these compounds are not suicide substrates of the enzyme. These effects are not observed with 2-methylresorcinol. The docking results indicate that the binding of met-tyrosinase with these resorcinols occurs in the same way, but not with 2-methylresorcinol, due to steric hindrance. The enzyme assays are performed in preenceof ascorbic acid or hydrogen peroxide. Molecular docking simulations and modeling, overview
-
-
?
additional information
?
-
-
the oxy form of tyrosinase (oxytyrosinase) hydroxylates alpha and beta-arbutin in ortho position of the phenolic hydroxyl group, giving rise to a complex formed by met-tyrosinase with the hydroxylated alpha or beta-arbutin. This complex can evolve in two ways: by oxidizing the originated o-diphenol to o-quinone and deoxy-tyrosinase, or by delivering the o-diphenol and met-tyrosinase to the medium, which would produce the self-activation of the system. If 3-methyl-2-benzothiazolinone hydrazone hydrochloride hydrate is used, the o-quinone is attacked, so that it becomes an adduct, which can be oxidized by another molecule of o-quinone, generating o-diphenol in the medium. In this way, the system reaches the steady state and originates a chromophore, which, in turn, has a high absorptivity in the visible spectrum and can be measured. The catalysis cannot be quantified because the quinones generated in both cases are unstable. 3-Methyl-2-benzothiazolinone hydrazone, MBTH, is a very potent nucleophile, which, in its deprotonated form, attacks the o-quinone generated by the action of tyrosinase on alpha- and beta-arbutin. The addition of hydrogen peroxide is required and transforms Em to Eox, which is able to hydroxylate arbutin, although the o-quinone that is originated is unstable
-
-
?
additional information
?
-
the proteolytically activated mushroom tyrosinase shows over 50% of its maximal activity in the range of pH 5-10 and accepts a wide range of substrates including mono- and diphenols, flavonols and chalcones. The activated AbPPO4 catalyzes both reactions observed for tyrosinase. The catechol oxidase activity proceeds typically with a rate two orders of magnitude faster than the hydroxylation and oxidation of monophenols. Of the tested substrates the enzyme exhibits the highest affinity and the lowest reaction rate for L-tyrosine. Activated AbPPO4 discriminates between enantiomers of tyrosine showing pronounced differences in the rate of the tyrosinase reaction. For tyrosine 1 mM of the L-enantiomer is converted at a rate of 1.22 U/mg, which is 2.58times faster than the rate on D-tyrosine. A slight increase in enantioselectivity is seen for the methyl ester of tyrosine
-
-
?
additional information
?
-
-
the proteolytically activated mushroom tyrosinase shows over 50% of its maximal activity in the range of pH 5-10 and accepts a wide range of substrates including mono- and diphenols, flavonols and chalcones. The activated AbPPO4 catalyzes both reactions observed for tyrosinase. The catechol oxidase activity proceeds typically with a rate two orders of magnitude faster than the hydroxylation and oxidation of monophenols. Of the tested substrates the enzyme exhibits the highest affinity and the lowest reaction rate for L-tyrosine. Activated AbPPO4 discriminates between enantiomers of tyrosine showing pronounced differences in the rate of the tyrosinase reaction. For tyrosine 1 mM of the L-enantiomer is converted at a rate of 1.22 U/mg, which is 2.58times faster than the rate on D-tyrosine. A slight increase in enantioselectivity is seen for the methyl ester of tyrosine
-
-
?
additional information
?
-
-
the reactivity, the monomer (catechin/epicatechin) or oligomer (e.g. dimer, trimer) existing in Rhododendron pulchrum proanthocyanidins can take the place of 3,4-dihydroxyphenylalanine
-
-
?
additional information
?
-
tyrosinase catalyzes the o-hydroxylation of monophenols to the corresponding o-diphenols and the subsequent conversion of the o-diphenols to the corresponding o-quinones
-
-
?
additional information
?
-
-
tyrosinase catalyzes the o-hydroxylation of monophenols to the corresponding o-diphenols and the subsequent conversion of the o-diphenols to the corresponding o-quinones
-
-
?
additional information
?
-
tyrosinase uses molecular oxygen as cosubstrate to catalyse the ortho-hydroxylation of monophenols to o-diphenols (monophenolase activity), and the oxidation of o-diphenols to o-quinones (diphenolase activity)
-
-
?
additional information
?
-
substrate specificity allows elucidation of a likely mechanism of aurone formation from 2,4,6,4-tetrahydroxychalcone or PHC involving both tyrosinase and catechol oxidase activities of the Antirrhinum majus PPO, pathway overview. Starting with THC, tyrosinase and catechol oxidase activity result in 3-hydroxylation and formation of the corresponding o-quinone. Whether aureusidine synthase PPO carries out the 3-hydroxylation reaction in vivo, or whether a cytochrome P450 chalcone 3-hydroxylase is also involved is not definitively established. Aureusidine synthase, EC 1.21.3.6, likely forms the same quinone from 2',3,4,4',6'-pentahydroxychalcone without the need for the 3-hydroxylation step. The resulting quinone is predicted to undergo a 2-step non-enzyme mediated rearrangement to form aureusidin
-
-
?
additional information
?
-
tyrosinase is a bifunctional enzyme that catalyzes the o-monohydroxylation of monophenols (phenols) to their corresponding o-diphenols (o-cresolase or monophenolase, EC 1.14.18.1) and their subsequent oxidation (catechol oxidase or diphenolase, EC 1.103.1) into reactive o-quinones. Molecular oxygen is used as an electron acceptor, and it is reduced to water in both the reactions. Subsequently, the resulting o-quinones undergo non-enzymatic oxido-reduction reactions with various nucleophilic moieties, producing intermediates which auto-polymerize spontaneously in dark brown pigments. The monophenolase activity is the initial rate-determining reaction in the process
-
-
?
additional information
?
-
-
tyrosinase is a bifunctional enzyme that catalyzes the o-monohydroxylation of monophenols (phenols) to their corresponding o-diphenols (o-cresolase or monophenolase, EC 1.14.18.1) and their subsequent oxidation (catechol oxidase or diphenolase, EC 1.103.1) into reactive o-quinones. Molecular oxygen is used as an electron acceptor, and it is reduced to water in both the reactions. Subsequently, the resulting o-quinones undergo non-enzymatic oxido-reduction reactions with various nucleophilic moieties, producing intermediates which auto-polymerize spontaneously in dark brown pigments. The monophenolase activity is the initial rate-determining reaction in the process
-
-
?
additional information
?
-
tyrosinase catalyzes the conversion of L-tyrosine to L-DOPA and then to dopachrome, which is subsequently polymerized spontaneously to melanin via a series of non-enzymatic reactions
-
-
?
additional information
?
-
-
tyrosinase catalyzes the conversion of L-tyrosine to L-DOPA and then to dopachrome, which is subsequently polymerized spontaneously to melanin via a series of non-enzymatic reactions
-
-
?
additional information
?
-
tyrosinase is a bifunctional enzyme that catalyzes the o-monohydroxylation of monophenols (phenols) to their corresponding o-diphenols (o-cresolase or monophenolase, EC 1.14.18.1) and their subsequent oxidation (catechol oxidase or diphenolase, EC 1.103.1) into reactive o-quinones. Molecular oxygen is used as an electron acceptor, and it is reduced to water in both the reactions. Subsequently, the resulting o-quinones undergo non-enzymatic oxido-reduction reactions with various nucleophilic moieties, producing intermediates which auto-polymerize spontaneously in dark brown pigments. The monophenolase activity is the initial rate-determining reaction in the process
-
-
?
additional information
?
-
tyrosinase catalyzes the conversion of L-tyrosine to L-DOPA and then to dopachrome, which is subsequently polymerized spontaneously to melanin via a series of non-enzymatic reactions
-
-
?
additional information
?
-
-
polyphenol oxidases can catalyze oxidation of o-diphenols to o-quinones and/or hydroxylation of monophenols to o-diphenols followed by the oxidation to o-benzoquinones
-
-
?
additional information
?
-
-
tyrosinase is a copper-containing enzyme that catalyzes two distinct reactions of melanin synthesis: the hydroxylation of tyrosine by monophenolase action and the oxidation of 3,4-dihydroxyphenylalanine (L-DOPA) to o-dopaquinone by diphenolase action
-
-
?
additional information
?
-
-
most plant polphenol oxidases have catechol oxidase activity (oxidation of o-diphenols to their corresponding o-quinones, EC1.10.3.1) and the ability to hydroxylate monophenols to o-diphenols (tyrosinase, EC 1.14.18.1)
-
-
?
additional information
?
-
-
enzyme catalyzes two distinct reactions: the o-hydroxylation of monophenols to o-diphenols (acts like cresolase (E.C. 1.14.18.1.)) and the oxidation of o-diphenols to o-quinones (acts like catecholase (E.C. 1.10.3.2.)). No activity towards monophenols (tyrosine) and low activity - towards trihydroxyphenol-phloroglucinol
-
-
?
additional information
?
-
-
protocatechuic acid (3,4-dihydroxybenzoic acid) shows little or no activity as a sole substrate
-
-
?
additional information
?
-
-
protocatechuic acid (3,4-dihydroxybenzoic acid) shows little or no activity as a sole substrate
-
-
?
additional information
?
-
-
protocatechuic acid (3,4-dihydroxybenzoic acid) shows little or no activity as a sole substrate
-
-
?
additional information
?
-
-
protocatechuic acid (3,4-dihydroxybenzoic acid) shows little or no activity as a sole substrate
-
-
?
additional information
?
-
-
protocatechuic acid (3,4-dihydroxybenzoic acid) shows little or no activity as a sole substrate
-
-
?
additional information
?
-
-
polyphenol oxidases can catalyze oxidation of o-diphenols to o-quinones and/or hydroxylation of monophenols to o-diphenols followed by the oxidation to o-benzoquinones
-
-
?
additional information
?
-
-
protocatechuic acid (3,4-dihydroxybenzoic acid) shows little or no activity as a sole substrate
-
-
?
additional information
?
-
-
protocatechuic acid (3,4-dihydroxybenzoic acid) shows little or no activity as a sole substrate
-
-
?
additional information
?
-
-
protocatechuic acid (3,4-dihydroxybenzoic acid) shows little or no activity as a sole substrate
-
-
?
additional information
?
-
-
protocatechuic acid (3,4-dihydroxybenzoic acid) shows little or no activity as a sole substrate
-
-
?
additional information
?
-
-
protocatechuic acid (3,4-dihydroxybenzoic acid) shows little or no activity as a sole substrate
-
-
?
additional information
?
-
polyphenol oxidases (PPOs) are nuclear-encoded copper-containing metalloproteins involved in either the hydroxylation of monophenols to o-diphenols (EC 1.14.18.1, monophenol monoxinase, tyrosinase, and cresolase) or dehydrogenation of o-diphenols to o-quinones (EC1.10.3.1, diphenol oxygen oxidoreductase and catecholase). The enzyme from Camellia sinensis oxidizes epicatechins to yield theaflavins and thearubigins
-
-
?
additional information
?
-
synthesis of theaflavins of polyphenol oxidase isozymes from tea leaves
-
-
?
additional information
?
-
synthesis of theaflavins of polyphenol oxidase isozymes from tea leaves
-
-
?
additional information
?
-
no activity with guaiacol. Synthesis of theaflavin an theaflavin gallates from different substrate by polyphenol oxidase, overview
-
-
?
additional information
?
-
no activity with guaiacol. Synthesis of theaflavin an theaflavin gallates from different substrate by polyphenol oxidase, overview
-
-
?
additional information
?
-
synthesis of theaflavin an theaflavin gallates from different substrate by polyphenol oxidase, overview
-
-
?
additional information
?
-
synthesis of theaflavin an theaflavin gallates from different substrate by polyphenol oxidase, overview
-
-
?
additional information
?
-
-
mechanical damage by Hemileia vastatrix fungus, the causal agent of the leaf orange rust disease, inoculation and Leucoptera coffeella, the coffee leaf miner, infestation caused different responses in PPO activity in different Coffea species, level of damage or resistance, overview
-
-
?
additional information
?
-
-
substrate specificity, overview, the enzyme catalyzes the hydroxylation of monophenols to o-diphenols, monophenolase activity EC 1.14.18.1, and the oxidation of the o-diphenols to o-quinones, diphenolase activity EC 1.10.3.1, cross-reaction analysis, overview
-
-
?
additional information
?
-
Coffea guarini
-
mechanical damage by Hemileia vastatrix fungus, the causal agent of the leaf orange rust disease, inoculation and Leucoptera coffeella, the coffee leaf miner, infestation caused different responses in PPO activity in different Coffea species, level of damage or resistance, overview
-
-
?
additional information
?
-
Coffea guarini
-
substrate specificity, overview, the enzyme catalyzes the hydroxylation of monophenols to o-diphenols, monophenolase activity EC 1.14.18.1, and the oxidation of the o-diphenols to o-quinones, diphenolase activity EC 1.10.3.1, cross-reaction analysis, overview
-
-
?
additional information
?
-
-
mechanical damage by Hemileia vastatrix fungus, the causal agent of the leaf orange rust disease, inoculation and Leucoptera coffeella, the coffee leaf miner, infestation caused different responses in PPO activity in different Coffea species, level of damage or resistance, overview
-
-
?
additional information
?
-
-
substrate specificity, overview, the enzyme catalyzes the hydroxylation of monophenols to o-diphenols, monophenolase activity EC 1.14.18.1, and the oxidation of the o-diphenols to o-quinones, diphenolase activity EC 1.10.3.1, cross-reaction analysis, overview
-
-
?
additional information
?
-
-
mechanical damage by Hemileia vastatrix fungus, the causal agent of the leaf orange rust disease, inoculation and Leucoptera coffeella, the coffee leaf miner, infestation caused different responses in PPO activity in different Coffea species, level of damage or resistance, overview
-
-
?
additional information
?
-
-
substrate specificity, overview, the enzyme catalyzes the hydroxylation of monophenols to o-diphenols, monophenolase activity EC 1.14.18.1, and the oxidation of the o-diphenols to o-quinones, diphenolase activity EC 1.10.3.1, cross-reaction analysis, overview
-
-
?
additional information
?
-
-
mechanical damage by Hemileia vastatrix fungus, the causal agent of the leaf orange rust disease, inoculation and Leucoptera coffeella, the coffee leaf miner, infestation caused different responses in PPO activity in different Coffea species, level of damage or resistance, overview
-
-
?
additional information
?
-
-
substrate specificity, overview, the enzyme catalyzes the hydroxylation of monophenols to o-diphenols, monophenolase activity EC 1.14.18.1, and the oxidation of the o-diphenols to o-quinones, diphenolase activity EC 1.10.3.1, cross-reaction analysis, overview
-
-
?
additional information
?
-
-
no activity with resorcinol, phenol, and 2-naphthol
-
-
?
additional information
?
-
substrate specificity allows elucidation of a likely mechanism of aurone formation from 2,4,6,4-tetrahydroxychalcone or PHC involving both tyrosinase and catechol oxidase activities of the Antirrhinum majus PPO, pathway overview. Starting with THC, tyrosinase and catechol oxidase activity result in 3-hydroxylation and formation of the corresponding o-quinone. Besides aurone synthase PPO, a cytochrome P450 chalcone 3-hydroxylase is also involved in the 3-hydroxylation step
-
-
?
additional information
?
-
-
no activity is detectable with L-tyrosine, tyramine or phenol as substrate
-
-
?
additional information
?
-
-
the enzyme catalyzes the hydroxylation of monophenols to o-diphenols, monophenolase activity EC 1.14.18.1, and the oxidation of the o-diphenols to o-quinones, diphenolase activity EC 1.10.3.1, cross-reaction analysis, overview
-
-
?
additional information
?
-
-
polyphenol oxidases can catalyze oxidation of o-diphenols to o-quinones and/or hydroxylation of monophenols to o-diphenols followed by the oxidation to o-benzoquinones
-
-
?
additional information
?
-
-
no activity with resorcinol, phenol, and 2-naphthol
-
-
?
additional information
?
-
-
no activity with resorcinol, phenol, and 2-naphthol
-
-
?
additional information
?
-
-
PPO is an enzyme concerning the o-hydroxylation of monophenols to o-diphenols acting as cresolase, EC 1.14.18.1, and the oxidation of o-diphenols to o-quinones acting as catecholase, EC 1.10.3.1
-
-
?
additional information
?
-
-
no activity with p-hydroxyphenylalanine
-
-
?
additional information
?
-
-
no activity with resorcinol, phenol, and 2-naphthol
-
-
?
additional information
?
-
-
polyphenol oxidases can catalyze oxidation of o-diphenols to o-quinones and/or hydroxylation of monophenols to o-diphenols followed by the oxidation to o-benzoquinones
-
-
?
additional information
?
-
-
polyphenol oxidases can catalyze oxidation of o-diphenols to o-quinones and/or hydroxylation of monophenols to o-diphenols followed by the oxidation to o-benzoquinones
-
-
?
additional information
?
-
Festuca sp.
-
polyphenol oxidases can catalyze oxidation of o-diphenols to o-quinones and/or hydroxylation of monophenols to o-diphenols followed by the oxidation to o-benzoquinones
-
-
?
additional information
?
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tyrosinase is known to be a key enzyme in melanin biosynthesis, involved in determining the color of mammalian skin and hair, various dermatological disorders, such as melasma, age spots and sites of actinic damage, arise from the accumulation of an excessive level of epidermal pigmentation
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the enzyme catalyzes the hydroxylation of monophenols to o-diphenols, monophenolase activity EC 1.14.18.1, and the oxidation of the o-diphenols to o-quinones, diphenolase activity EC 1.10.3.1, cross-reaction analysis, overview
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tyrosinase is a copper-containing enzyme that catalyzes two distinct reactions of melanin synthesis: the hydroxylation of tyrosine by monophenolase action and the oxidation of 3,4-dihydroxyphenylalanine (L-DOPA) to o-dopaquinone by diphenolase action
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no activity with [3-(3,5-dihydroxyphenyl)-1-propanoic acid]
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no activity with [3-(3,5-dihydroxyphenyl)-1-propanoic acid]
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In Juglans regia, PPO is encoded by a single gene and has both catechol oxidase activity (oxidation of o-diphenols to their corresponding o-quinones, EC 1.10.3.1) and tyrosinase activity (hydroxylation of monophenols to o-diphenols, EC 1.14.18.1)
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tyrosinases and catechol oxidases (EC 1.10.3.1) are members of the class of type III copper enzymes. While tyrosinases accept both mono- and o-diphenols as substrates, only the latter substrate is converted by catechol oxidases. The crystal structure reveals that the distinction between mono- and diphenolase activity does not depend on the degree of restriction of the active site, and thus a more important role for amino acid residues located at the entrance to and in the second shell of the active site is proposed
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the purified native enzyme shows a rather high monophenolase activity compared to diphenolase activity
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no activity with vanillin and tyrosine as a substrate
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pyrogallol is the most suitable substrate, followed by catechol and 4-methylcatechol. No activity is detected toward L-tyrosine, a monophenolic substrate
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in Juglans regia, PPO is encoded by a single gene and has both catechol oxidase activity (oxidation of o-diphenols to their corresponding o-quinones, EC 1.10.3.1) and tyrosinase activity (hydroxylation of monophenols to o-diphenols, EC 1.14.18.1). The Larrea tridentate PPO gene product acts as a (+)-larreatricin 3'-hydroxylase in vivo
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the purified lenzyme also shows highly enantiospecific larreatricin-3'-hydroxylase activity, EC 1.14.99.47
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polyphenol oxidases can catalyze oxidation of o-diphenols to o-quinones and/or hydroxylation of monophenols to o-diphenols followed by the oxidation to o-benzoquinones
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Lolium sp.
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polyphenol oxidases can catalyze oxidation of o-diphenols to o-quinones and/or hydroxylation of monophenols to o-diphenols followed by the oxidation to o-benzoquinones
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the PPO from Lonicera confusa exhibits both diphenolase and triphenolase activities, substrates monophenol (L-tyrosine), diphenols (L-DOPA, catechol, caffeic acid) and triphenols (pyrogallic acid, methyl gallate and gallic acid) are used by the enzyme
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substrate-binding site of cherry PPO has a high affinity for small o-diphenols, such as catechol, 4-methylcatechol or L-dopa, and less affinity for the larger o-diphenols, caffeic acid, and triphenol-pyrogallol
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accepts both mono- and diphenols as substrates. The hydroxylation ability of the enzyme is also referred to cresolase or monophenolase activity (EC 1.14.18.1), and the oxidation ability to catecholase or diphenolase activity (EC 1.10.3.1). The tyrosinases generally have noticeably lower activity on monophenols than on di- or triphenols. The activity of tyrosinase on tyrosine is particularly low. Ferulic acid is not a substrate to any of the tyrosinases. The substrate p-coumaric acid is rapidly oxidized only by tyrosinase from Trichoderma reesei
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tyrosinases are able to catalyze the ortho-hydroxylation of monophenols to o-diphenols (monophenolase activity, EC 1.14.18.1) coupled with the subsequent two-electron oxidation of o-diphenols to the corresponding o-quinones (diphenolase activity, EC 1.10.3.1). The o-diphenols formed in the hydroxylation step remain in the active centre and are oxidized to the quinonic state. During the TYR mediated hydroxylation and oxidation of one molecule of monophenol, one molecule of dioxygen is reduced to water. Catechol oxidases, EC 1.10.3.1, lack the monophenolase activity and are thus only capable of oxidizing o-diphenols
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tyrosinases are able to catalyze the ortho-hydroxylation of monophenols to o-diphenols (monophenolase activity, EC 1.14.18.1) coupled with the subsequent two-electron oxidation of o-diphenols to the corresponding o-quinones (diphenolase activity, EC 1.10.3.1). The o-diphenols formed in the hydroxylation step remain in the active centre and are oxidized to the quinonic state. During the TYR mediated hydroxylation and oxidation of one molecule of monophenol, one molecule of dioxygen is reduced to water. Catechol oxidases, EC 1.10.3.1, lack the monophenolase activity and are thus only capable of oxidizing o-diphenols
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soaking of crystals with a monophenolic (tyramine) and a diphenolic (dopamine) substrate in 50 mM Tris-HCl, pH 7.5, 200 mM NaCl, 20% PEG 3350, 20-25% PEG 1500, using SDS as an activator in order to perform in crystallo activity tests
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soaking of crystals with a monophenolic (tyramine) and a diphenolic (dopamine) substrate in 50 mM Tris-HCl, pH 7.5, 200 mM NaCl, 20% PEG 3350, 20-25% PEG 1500, using SDS as an activator in order to perform in crystallo activity tests
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caffeic acid, ferulic acid, epicatechin, and phenol are no substrates
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catalyzing the rate-limiting step for melanin biosynthesis
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the enzyme plays a role in enzymatic browning, rapid discolouration of leaf, stem and root tissue after injury and strong pigmentation of tissue extracts, PPO and phenolic compounds could be an important part of the plants defence system against pests and diseases, including root parasitic nematodes, e.g. Radopholus similis
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no activity with L-tyrosine by the root and the pulp enzyme, the enzyme catalyzes the hydroxylation of monophenols to o-diphenols, monophenolase activity EC 1.14.18.1, and the oxidation of the o-diphenols to o-quinones, diphenolase activity EC 1.10.3.1, cross-reaction analysis, overview
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CATPO shows both catalase and phenol oxidase activities, its major activity is the catalase-mediated decomposition of hydrogen peroxide, but it also catalyzes peroxide-independent phenol oxidation
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no activity is detected against L-tyrosine and common laccase substrates such as 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) and syringaldazine with the exception of weak activity with p-hydroquinone
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the enzyme catalyzes the hydroxylation of monophenols to o-diphenols, monophenolase activity EC 1.14.18.1, and the oxidation of the o-diphenols to o-quinones, diphenolase activity EC 1.10.3.1, cross-reaction analysis, overview
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tyrosinase is a copper-containing enzyme that catalyzes two distinct reactions of melanin synthesis: the hydroxylation of tyrosine by monophenolase action and the oxidation of 3,4-dihydroxyphenylalanine (L-DOPA) to o-dopaquinone by diphenolase action
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native hemocyanin in whiteleg shrimp does not have phenoloxidase activity, but when incubated with SDS, hemocyanin is converted into hemocyanin-phenoloxidase
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polyphenol oxidases can catalyze oxidation of o-diphenols to o-quinones and/or hydroxylation of monophenols to o-diphenols followed by the oxidation to o-benzoquinones
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polyphenol oxidases can catalyze oxidation of o-diphenols to o-quinones and/or hydroxylation of monophenols to o-diphenols followed by the oxidation to o-benzoquinones
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the enzyme catalyzes the hydroxylation of monophenols to o-diphenols, monophenolase activity EC 1.14.18.1, and the oxidation of the o-diphenols to o-quinones, diphenolase activity EC 1.10.3.1, cross-reaction analysis, overview
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polyphenol oxidases can catalyze oxidation of o-diphenols to o-quinones and/or hydroxylation of monophenols to o-diphenols followed by the oxidation to o-benzoquinones
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vanillic acid, 1-naphthol, 2,6-dimethoxyphenol, and resorcinol are no substrates for tyrosinase
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the enzyme shows no activity with caffeic acid, ferulic acid, 4-coumaric acid, p-cresol, and L-tyrosine
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substrate specificity, overview
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the purified tyrosinase from hemolymph shows both monophenolase, EC 1.14.18.1, and diphenolase, EC 1.10.3.1, activity and therefore it can be defined as a true tyrosinase, the purified hemocynin does not show any tyrosinase activity
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polyphenol oxidases can catalyze oxidation of o-diphenols to o-quinones and/or hydroxylation of monophenols to o-diphenols followed by the oxidation to o-benzoquinones
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the enzyme is classified as a catecholase type polyphenol oxidase
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PPO activity is associated with color changes associated with browning and lycopene degradation, the commercial variety Naomi is more susceptible to enzymatic browning than the local varieties Pizzutello, Rosa Maletto and PO228, due to higher PPO activity levels, lycopene is an antioxidant agent that reconstitutes the polyphenols oxidized by the action of PPO
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accepts both mono- and diphenols as substrates. The hydroxylation ability of the enzyme is also referred to cresolase or monophenolase activity (EC 1.14.18.1), and the oxidation ability to catecholase or diphenolase activity (EC 1.10.3.1). The tyrosinases generally have noticeably lower activity on monophenols than on di- or triphenols. Ferulic acid is not a substrate to any of the tyrosinases. The substrate p-coumaric acid is rapidly oxidized only by tyrosinase from Trichoderma reesei
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the partially purified enzyme has both cresolase and catecholase activity. Activity is lower toward monophenols than diphenols
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no activity with ferulic acid and phenol
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activity with phenolic and diphenolic substrates, also performing the reaction of tyrosinase, a ortho-hydroxylation of monophenols, EC 1.14.18.1, and the oxidation of catechols to ortho-quinones, the diphenolase activity, EC 1.10.3.1, overview
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the enzyme catalyzes the hydroxylation of monophenols to o-diphenols, monophenolase activity EC 1.14.18.1, and the oxidation of the o-diphenols to o-quinones, diphenolase activity EC 1.10.3.1, cross-reaction analysis, overview
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2-chlorophenol is not reactive with tyrosinase
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tyrosinase exhibits monophenolase and diphenolase activity
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the enzyme catalyzes the hydroxylation of monophenols to o-diphenols, monophenolase activity EC 1.14.18.1, and the oxidation of the o-diphenols to o-quinones, diphenolase activity EC 1.10.3.1, cross-reaction analysis, overview
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tyrosinase is a copper-containing enzyme that catalyzes two distinct reactions of melanin synthesis: the hydroxylation of tyrosine by monophenolase action and the oxidation of 3,4-dihydroxyphenylalanine (L-DOPA) to o-dopaquinone by diphenolase action
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additional information
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accepts both mono- and diphenols as substrates. The hydroxylation ability of the enzyme is also referred to cresolase or monophenolase activity (EC 1.14.18.1), and the oxidation ability to catecholase or diphenolase activity (EC 1.10.3.1). The tyrosinases generally have noticeably lower activity on monophenols than on di- or triphenols, the activity of tyrosinase from Pycnoporus sanguineus on tyrosine is particularly low. Ferulic acid is not a substrate to any of the tyrosinases. The substrate p-coumaric acid is rapidly oxidized only by tyrosinase from Trichoderma reesei
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broad substrate specificity, overview, no or poor activity with 4-aminophenol, 3-hydroxyanthranilic acid, tyramine, 2-coumaric acid, ferulic acid, and aniline, tyrosinase is a mono-oxygenase and a bifunctional enzyme that catalyzes the o-hydroxylation of monophenols and subsequent oxidation of o-diphenols to quinones, the enzyme thus accepts monophenols and diphenols as substrates, and the monophenolase activity is the initial rate-determining reaction
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accepts both mono- and diphenols as substrates. The hydroxylation ability of the enzyme is also referred to cresolase or monophenolase activity (EC 1.14.18.1), and the oxidation ability to catecholase or diphenolase activity (EC 1.10.3.1). The tyrosinases generally have noticeably lower activity on monophenols than on di- or triphenols. Tyrosinase from Trichoderma reesei shows the best ability to crosslink alpha-casein. Tyrosinase from Trichoderma reesei also has the highest activity on most of the tested monophenols, and shows noticeable short lag periods prior to the oxidation. Ferulic acid is not a substrate to any of the tyrosinases
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polyphenol oxidases can catalyze oxidation of o-diphenols to o-quinones and/or hydroxylation of monophenols to o-diphenols followed by the oxidation to o-benzoquinones
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substrate specificity, overview, activity with phenolic and diphenolic substrates, also performing the reaction of tyrosinase, a ortho-hydroxylation of monophenols, EC 1.14.18.1, and the oxidation of catechols to ortho-quinones, the diphenolase activity, EC 1.10.3.1, overview
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polyphenol oxidase is a copper-containing enzyme that, in the presence of oxygen, catalyses the hydroxylation of monophenols to o-diphenols (cresolase activity) and the oxidation of o-diphenols to their corresponding o-quinones (catecholase activity)
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polyphenoloxidases, PPOs, from Dornfelder and Riesling grapes display both monophenolase and diphenolase activity
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substrate specificity in descendent order of activity from Vmax/Km: caffeic acid, 4-methylcatechol, catechol, pyrogallol
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catalyse the hydroxylation of monophenols to o-dihydroxyphenols (E.C. 1.14.18.1), and the oxidation of o-dihydroxyphenols to o-quinones (E.C. 1.10.3.2). PPO activities with diphenolic substrates are higher than with monophenolic substrate (tyrosine) in both embryo and endosperm tissues. Time course of PPO activities in embryo and endosperm of maize seeds treated with boron during and following germination is shown
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