Target type: molecularfunction
Catalysis of the reaction: L-tyrosine + O2 = L-DOPAquinone + H2O. This reaction can use both monophenols (such as tyrosine) and catechols (o-diphenols) as substrates. [PMID:4965136, RHEA:18117]
Tyrosinase activity is a crucial enzymatic process that plays a vital role in melanin biosynthesis. This activity is catalyzed by the enzyme tyrosinase, which is a copper-containing enzyme belonging to the type 3 copper protein family. Tyrosinase catalyzes two key reactions in the melanin synthesis pathway:
1. **Hydroxylation of L-tyrosine to L-DOPA:** Tyrosinase acts as a monooxygenase, incorporating molecular oxygen into L-tyrosine to produce L-DOPA (3,4-dihydroxyphenylalanine). This reaction is the rate-limiting step in melanin biosynthesis.
2. **Oxidation of L-DOPA to dopaquinone:** Tyrosinase also acts as an oxidase, oxidizing L-DOPA to dopaquinone. This reaction is crucial as it initiates the polymerization cascade that leads to the formation of melanin pigments.
Dopaquinone is highly reactive and undergoes a series of complex reactions, including auto-oxidation, cyclization, and polymerization, to generate different types of melanin pigments, such as eumelanin (brown-black) and pheomelanin (red-yellow).
Tyrosinase activity is essential for the pigmentation of skin, hair, and eyes. It is also involved in various biological processes, including immune defense, antioxidant activity, and protection against UV radiation. Dysregulation of tyrosinase activity can lead to various pigmentation disorders, such as albinism, vitiligo, and melanoma.
In summary, tyrosinase activity is an enzymatic process that plays a central role in melanin biosynthesis by catalyzing the hydroxylation of L-tyrosine to L-DOPA and the oxidation of L-DOPA to dopaquinone, initiating the polymerization cascade that generates melanin pigments. This activity is crucial for pigmentation and various biological processes.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Tyrosinase | A tyrosinase that is encoded in the genome of human. [PRO:DNx, UniProtKB:P14679] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| 4-hydroxybenzoic acid | 4-hydroxybenzoic acid : A monohydroxybenzoic acid that is benzoic acid carrying a hydroxy substituent at C-4 of the benzene ring. | monohydroxybenzoic acid | algal metabolite; plant metabolite |
| benzaldehyde | benzaldehydes | EC 3.1.1.3 (triacylglycerol lipase) inhibitor; EC 3.5.5.1 (nitrilase) inhibitor; flavouring agent; fragrance; odorant receptor agonist; plant metabolite | |
| benzoic acid | aromatic carboxylic acid : Any carboxylic acid in which the carboxy group is directly bonded to an aromatic ring. benzoic acid : A compound comprising a benzene ring core carrying a carboxylic acid substituent. Benzoic Acid: A fungistatic compound that is widely used as a food preservative. It is conjugated to GLYCINE in the liver and excreted as hippuric acid. | benzoic acids | algal metabolite; antimicrobial food preservative; drug allergen; EC 1.13.11.33 (arachidonate 15-lipoxygenase) inhibitor; EC 3.1.1.3 (triacylglycerol lipase) inhibitor; human xenobiotic metabolite; plant metabolite |
| cuminaldehyde | cuminaldehyde : A member of the class of benzaldehydes that is benzaldehyde substituted by an isopropyl group at position 4. It is a component of essential oils from Cumin and exhibits insecticidal activities. | benzaldehydes | insecticide; plant metabolite; volatile oil component |
| hydroquinone | benzenediol; hydroquinones | antioxidant; carcinogenic agent; cofactor; Escherichia coli metabolite; human xenobiotic metabolite; mouse metabolite; skin lightening agent | |
| hexylresorcinol | resorcinols | ||
| beta-thujaplicin | beta-thujaplicin : A monoterpenoid that is cyclohepta-2,4,6-trien-1-one substituted by a hydroxy group at position 2 and an isopropyl group at position 4. Isolated from Thuja plicata and Chamaecyparis obtusa, it exhibits antimicrobial activities. beta-thujaplicin: structure | cyclic ketone; enol; monoterpenoid | antibacterial agent; antifungal agent; antineoplastic agent; antiplasmodial drug; plant metabolite |
| kojic acid | 4-pyranones; enol; primary alcohol | Aspergillus metabolite; EC 1.10.3.1 (catechol oxidase) inhibitor; EC 1.10.3.2 (laccase) inhibitor; EC 1.13.11.24 (quercetin 2,3-dioxygenase) inhibitor; EC 1.14.18.1 (tyrosinase) inhibitor; EC 1.4.3.3 (D-amino-acid oxidase) inhibitor; NF-kappaB inhibitor; skin lightening agent | |
| resorcinol | resorcinol : A benzenediol that is benzene dihydroxylated at positions 1 and 3. resorcinol: RN given refers to parent cpd; structure in Merck Index, 9th ed, #7951 | benzenediol; phenolic donor; resorcinols | erythropoietin inhibitor; sensitiser |
| levodopa | L-dopa : An optically active form of dopa having L-configuration. Used to treat the stiffness, tremors, spasms, and poor muscle control of Parkinson's disease Levodopa: The naturally occurring form of DIHYDROXYPHENYLALANINE and the immediate precursor of DOPAMINE. Unlike dopamine itself, it can be taken orally and crosses the blood-brain barrier. It is rapidly taken up by dopaminergic neurons and converted to DOPAMINE. It is used for the treatment of PARKINSONIAN DISORDERS and is usually given with agents that inhibit its conversion to dopamine outside of the central nervous system. | amino acid zwitterion; dopa; L-tyrosine derivative; non-proteinogenic L-alpha-amino acid | allelochemical; antidyskinesia agent; antiparkinson drug; dopaminergic agent; hapten; human metabolite; mouse metabolite; neurotoxin; plant growth retardant; plant metabolite; prodrug |
| salicylaldehyde | o-hydroxybenzaldehyde: structure in first source | hydroxybenzaldehyde | nematicide; plant metabolite |
| xanthone | xanthone : The parent compound of the xanthone class consisting of xanthene bearing a single oxo substituent at position 9. | xanthones | insecticide |
| butylphen | 4-tert-butylphenol : A member of the class of phenols that is phenol substituted with a tert-butyl group at position 4. butylphen: irritant; structure | phenols | allergen |
| gamma-thujaplicin | 2-hydroxy-5-isopropyl- 2,4,6-cycloheptatrienone: a metal chelating agent | cyclic ketone | |
| 3-hydroxy-1-benzopyran-2-one | 3-hydroxycoumarin: Photoprotective from sea urchin gametes and embryonic cells; structure in first source hydroxycoumarin : Any coumarin carrying at least one hydroxy substituent. | hydroxycoumarin | |
| 2-tert-butylhydroquinone | 2-tert-butylhydroquinone : A member of the class of hydroquinones in which one of the ring hydrogens of hydroquinone is replaced by a tert-butyl group. 2-tert-butylhydroquinone: an anticarcinogenic and chemopreventive agent | hydroquinones | food antioxidant |
| 4-anisaldehyde | 4-anisaldehyde: RN given refers to cpd with specified locants for methoxy moieties; structure in Merck, 9th ed, #696 p-methoxybenzaldehyde : A member of the class of benzaldehydes consisting of benzaldehyde itself carrying a methoxy substituent at position 4. | benzaldehydes | bacterial metabolite; human urinary metabolite; insect repellent; plant metabolite |
| 2-hydroxy-4-methoxybenzaldehyde | 2-hydroxy-4-methoxybenzaldehyde: from African medicinal plants: Mondia whitei (Apocynaceae), Rhus vulagaris (Anacardiaceae), Sclerocarya caffra (Anacardiaceae) | methoxybenzenes; phenols | |
| 1-hydroxy-2(1h)-pyridinone | 1-hydroxy-2(1H)-pyridinone: structure in first source | ||
| 2-Methoxyxanthone | xanthones | ||
| alpha-thujaplicin | alpha-thujaplicin: structure in first source | ||
| arctiin | arctiin: from fruits of Arctium lappa L; RN given refers to (3R-trans)-isomer; RN for cpd without isomeric designation not avail 12/92 | glycoside; lignan | |
| glabridin | hydroxyisoflavans | antiplasmodial drug | |
| moracin m | moracin M: has been isolated from Morus alba L.; structure in first source | benzofurans | |
| 4-n-butylresorcinol | 4-n-butylresorcinol: structure in first source | resorcinols | |
| 4-methoxyxanthone | 4-methoxyxanthone: a vasodilator; structure in first source | ||
| mimosine | L-mimosine : An L-alpha-amino acid that is propionic acid substituted by an amino group at position 2 and a 3-hydroxy-4-oxopyridin-1(4H)-yl group at position 3 (the 2S-stereoisomer). It a non-protein plant amino acid isolated from Mimosa pudica. | 4-pyridones; amino acid zwitterion; non-proteinogenic L-alpha-amino acid | EC 1.14.18.1 (tyrosinase) inhibitor; plant metabolite |
| arbutin | hydroquinone O-beta-D-glucopyranoside : A monosaccharide derivative that is hydroquinone attached to a beta-D-glucopyranosyl residue at position 4 via a glycosidic linkage. | beta-D-glucoside; monosaccharide derivative | Escherichia coli metabolite; plant metabolite |
| resveratrol | trans-resveratrol : A resveratrol in which the double bond has E configuration. | resveratrol | antioxidant; phytoalexin; plant metabolite; quorum sensing inhibitor; radical scavenger |
| glabrene | glabrene: structure in first source | isoflavonoid | |
| glyasperin D | glyasperin D : A member of the class of hydroxyisoflavans that is (R)-isoflavan substituted by hydroxy groups at positions 2' and 4', methoxy groups at positions 5 and 7 and a prenyl group at position 6. It has been isolated from Glycyrrhiza uralensis. | aromatic ether; hydroxyisoflavans; methoxyisoflavan | plant metabolite |
| 6-hydroxyindole | 6-hydroxyindole: structure in first source | ||
| trans-4-coumaric acid | 4-coumaric acid : A coumaric acid in which the hydroxy substituent is located at C-4 of the phenyl ring. hydroxycinnamic acid : Any member of the class of cinnamic acids carrying one or more hydroxy substituents. trans-4-coumaric acid : The trans-isomer of 4-coumaric acid. | 4-coumaric acid | food component; mouse metabolite; plant metabolite |
| phenylthiourea | N-phenylthiourea : A member of the class of thioureas that is thiourea in which one of the hydrogens is replaced by a phenyl group. Depending on their genetic makeup, humans find it either very bitter-tasting or tasteless. This unusual property resulted in N-phenylthiourea being used in paternity testing prior to the advent of DNA testing. Phenylthiourea: Phenylthiourea is a THIOUREA derivative containing a phenyl ring. Depending on their genetic makeup, humans can find it either bitter-tasting or tasteless. | thioureas | EC 1.14.18.1 (tyrosinase) inhibitor |
| isoeugenol | trans-isoeugenol : The trans-stereoisomer of isoeugenol. | isoeugenol | plant metabolite |
| curcumin | curcumin : A beta-diketone that is methane in which two of the hydrogens are substituted by feruloyl groups. A natural dyestuff found in the root of Curcuma longa. Curcumin: A yellow-orange dye obtained from tumeric, the powdered root of CURCUMA longa. It is used in the preparation of curcuma paper and the detection of boron. Curcumin appears to possess a spectrum of pharmacological properties, due primarily to its inhibitory effects on metabolic enzymes. | aromatic ether; beta-diketone; diarylheptanoid; enone; polyphenol | anti-inflammatory agent; antifungal agent; antineoplastic agent; biological pigment; contraceptive drug; dye; EC 1.1.1.205 (IMP dehydrogenase) inhibitor; EC 1.1.1.21 (aldehyde reductase) inhibitor; EC 1.1.1.25 (shikimate dehydrogenase) inhibitor; EC 1.6.5.2 [NAD(P)H dehydrogenase (quinone)] inhibitor; EC 1.8.1.9 (thioredoxin reductase) inhibitor; EC 2.7.10.2 (non-specific protein-tyrosine kinase) inhibitor; EC 3.5.1.98 (histone deacetylase) inhibitor; flavouring agent; food colouring; geroprotector; hepatoprotective agent; immunomodulator; iron chelator; ligand; lipoxygenase inhibitor; metabolite; neuroprotective agent; nutraceutical; radical scavenger |
| 4-hydroxy-5-methyl-3(2h)-furanone | 4-hydroxy-5-methyl-3-furanone : A member of the class of furans that is 5-methyl-2,3-dihydrofuran with a hydroxy group at position 4 and a keto group at position 3. | cyclic ketone; enol; furans | metabolite |
| quercetin | 7-hydroxyflavonol; pentahydroxyflavone | antibacterial agent; antineoplastic agent; antioxidant; Aurora kinase inhibitor; chelator; EC 1.10.99.2 [ribosyldihydronicotinamide dehydrogenase (quinone)] inhibitor; geroprotector; phytoestrogen; plant metabolite; protein kinase inhibitor; radical scavenger | |
| luteolin | 3'-hydroxyflavonoid; tetrahydroxyflavone | angiogenesis inhibitor; anti-inflammatory agent; antineoplastic agent; apoptosis inducer; c-Jun N-terminal kinase inhibitor; EC 2.3.1.85 (fatty acid synthase) inhibitor; immunomodulator; nephroprotective agent; plant metabolite; radical scavenger; vascular endothelial growth factor receptor antagonist | |
| apigetrin | apigenin 7-O-beta-D-glucoside : A glycosyloxyflavone that is apigenin substituted by a beta-D-glucopyranosyl moiety at position 7 via a glycosidic linkage. apigetrin: structure given in first source | beta-D-glucoside; dihydroxyflavone; glycosyloxyflavone; monosaccharide derivative | antibacterial agent; metabolite; non-steroidal anti-inflammatory drug |
| quercetin 3-o-glucopyranoside | quercetin 3-O-beta-D-glucopyranoside : A quercetin O-glucoside that is quercetin with a beta-D-glucosyl residue attached at position 3. Isolated from Lepisorus contortus, it exhibits antineoplastic activityand has been found to decrease the rate of polymerization and sickling of red blood cells quercetin 3-O-glucopyranoside: structure in first source | beta-D-glucoside; monosaccharide derivative; quercetin O-glucoside; tetrahydroxyflavone | antineoplastic agent; antioxidant; antipruritic drug; bone density conservation agent; geroprotector; histamine antagonist; osteogenesis regulator; plant metabolite |
| kaempferol | 7-hydroxyflavonol; flavonols; tetrahydroxyflavone | antibacterial agent; geroprotector; human blood serum metabolite; human urinary metabolite; human xenobiotic metabolite; plant metabolite | |
| hispidol | hispidol : A hydroxyaurone that is aurone substituted by hydroxy groups at positions 6 and 4' respectively. | hydroxyaurone | plant metabolite |
| 7-hydroxycoumarin | 7-oxycoumarin: derivatives have anti-oxidant properties umbelliferone : A hydroxycoumarin that is coumarin substituted by a hydroxy group ay position 7. | hydroxycoumarin | fluorescent probe; food component; plant metabolite |
| euxanthone | euxanthone : A member of the class of xanthones that is 9H-xanthene substituted by hydroxy group at positions 1 and 7 and an oxo group at position 9. It has been isolated from Cratoxylum cochinchinense. | phenols; xanthones | metabolite; plant metabolite |
| trans-2,3',4,5'-tetrahydroxystilbene | trans-2,3',4,5'-tetrahydroxystilbene: hydroxystilbene oxyresveratrol | stilbenoid | |
| linarin | linarin: flavone glycoside isolated from leaves of Linaria japonica MIQ | ||
| methyl-p-coumarate | 4-coumaric acid methyl ester : A cinnamate ester that is the methyl ester of 4-coumaric acid. methyl-p-coumarate: structure in first source | 4-coumaric acid methyl ester | |
| tiliroside | tiliroside: isolated from seeds of Eremocarpus setigerus | cinnamate ester; glycosyloxyflavone; monosaccharide derivative; trihydroxyflavone | plant metabolite |
| tilianin | tilianin: from several medicinal plants including Agastache rugosa and Dracocephalum moldavia | ||
| 2,4,3',5'-tetramethoxystilbene | 2,4,3',5'-tetramethoxystilbene: potent inhibitor of human cytochrome P450 1B1; an antihypertensive agent; structure in first source | ||
| 1-hydroxyxanthone | 1-hydroxyxanthone: structure in first source | ||
| Norartocarpetin | flavones | ||
| 3,4-dihydroxy-xanthone | 3,4-dihydroxy-xanthone: structure given in first source | ||
| hylin | |||
| apigenin-7-o-rutinoside | |||
| morachalcone a | morachalcone A: tyrosinase inhibitor from the wood of Artocarpus heterophyllus; structure in first source | chalcones | |
| 2,4,2',4'-Tetrahydroxychalcone | chalcones | ||
| 4-(1-phenylethyl)resorcinol | 4-(1-phenylethyl)resorcinol: a depigmenting agent for treatment of solar lentigines; structure in first source | ||
| 3-hydroxyphloretin | 3-hydroxyphloretin: compound from Formosan apple that reduces tyrosinase activity in human epidermal melanocytes; structure in first source | chalcones | |
| subamolide a | subamolide A: cytotoxic constituent of the stems of Cinnamomum subavenium; structure in first source | ||
| feruloyldopamine | feruloyldopamine: a dopamine metabolite isolated from tomatoes after infection by Pseudomonas syringae; structure in first source | ||
| ascorbic acid | Ascorbic Acid: A six carbon compound related to glucose. It is found naturally in citrus fruits and many vegetables. Ascorbic acid is an essential nutrient in human diets, and necessary to maintain connective tissue and bone. Its biologically active form, vitamin C, functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant. L-ascorbate : The L-enantiomer of ascorbate and conjugate base of L-ascorbic acid, arising from selective deprotonation of the 3-hydroxy group. Required for a range of essential metabolic reactions in all animals and plants. L-ascorbic acid : The L-enantiomer of ascorbic acid and conjugate acid of L-ascorbate. vitamin C : Any member of a group of vitamers that belong to the chemical structural class called butenolides that exhibit biological activity against vitamin C deficiency in animals. The vitamers include L-ascorbic acid and its salt, ionized and oxidized forms. | ascorbic acid; vitamin C | coenzyme; cofactor; flour treatment agent; food antioxidant; food colour retention agent; geroprotector; plant metabolite; skin lightening agent |