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Literature summary for 1.14.18.1 extracted from

  • Garcia-Jimenez, A.; Teruel-Puche, J.A.; Garcia-Ruiz, P.A.; Saura-Sanmartin, A.; Berna, J.; Garcia-Canovas, F.; Rodriguez-Lopez, J.N.
    Structural and kinetic considerations on the catalysis of deoxyarbutin by tyrosinase (2017), PLoS ONE, 12, e0187845 .
    View publication on PubMedView publication on EuropePMC
Search for more literature for 1.14.18.1

Inhibitors

Inhibitors Comment Organism Structure
ascorbic acid
-
 Agaricus bisporus
beta-arbutin competitive Agaricus bisporus
deoxyarbutin competitive, a potent inhibitor of tyrosinase that can also act as substrate of the enzyme, shows membrane breaking and toxicity towards melanosomes, induces hydroxyl free radicals. Inhibition mechanism, overview Agaricus bisporus
deoxyfuran
-
 Agaricus bisporus
fluorodeoxyarbutin
-
 Agaricus bisporus
hydroquinone shows membrane breaking and toxicity towards melanosomes, and induces hydroxyl free radicals Agaricus bisporus
thiodeoxyarbutin
-
 Agaricus bisporus

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
0.033
-
 deoxyarbutin pH and temperature not specified in the publication Agaricus bisporus
3
-
 beta-arbutin pH and temperature not specified in the publication Agaricus bisporus

Metals/Ions

Metals/Ions Comment Organism Structure
Cu2+ a copper-containing enzyme, the catalytic centre of tyrosinase has two copper atoms each coordinated with three histidine residues. These copper atoms have different oxidation and coordination modes, depending on the enzymatic form: Cu2+Cu2+ in Em (metatyrosinase), Cu1+Cu1+ in Ed (deoxytyrosinase), and Cu2+Cu2+O22- in Eox (oxytyrosinase) Agaricus bisporus

Organism

Organism UniProt Comment Textmining
Agaricus bisporus C7FF04
-
-

Source Tissue

Source Tissue Comment Organism Textmining
commercial preparation
-
 Agaricus bisporus
-

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
beta-arbutin + O2
-
 Agaricus bisporus ?
-
 ?
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 Agaricus bisporus ?
-
 ?
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) Agaricus bisporus ?
-
 ?

Synonyms

Synonyms Comment Organism
mushroom tyrosinase
-
 Agaricus bisporus

Turnover Number [1/s]

Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
1.95
-
 deoxyarbutin pH and temperature not specified in the publication Agaricus bisporus
3.77
-
 beta-arbutin pH and temperature not specified in the publication Agaricus bisporus

Ki Value [mM]

Ki Value [mM] Ki Value maximum [mM] Inhibitor Comment Organism Structure
0.04
-
 deoxyarbutin inhibition of diphenolase activity, pH and temperature not specified in the publication Agaricus bisporus
0.078
-
 deoxyarbutin inhibition of monophenolase activity, pH and temperature not specified in the publication Agaricus bisporus
0.9
-
 beta-arbutin inhibition of diphenolase activity, pH and temperature not specified in the publication Agaricus bisporus
1.42
-
 beta-arbutin inhibition of monophenolase activity, pH and temperature not specified in the publication Agaricus bisporus

General Information

General Information Comment Organism
additional information molecular dynamic computational simulations of tyrosinase and the interaction of beta-arbutin, deoxyarbutin and their o-diphenol products with tyrosinase show how these ligands bind at the copper centre of tyrosinase, using enzyme crystal structure, PDB ID 2Y9W. The presence of an energy barrier in the release of the o-diphenol product of deoxyarbutin, which is not present in the case of beta-arbutin, together with the differences in polarity and, consequently differences in their interaction with water explain the differences in the kinetic behaviour of both compounds. The release of the o-diphenol product of deoxyarbutin from the active site might be slower than in the case of beta-arbutin, contributing to its oxidation to a quinone before being released from the protein into the water phase. Computational simulations of o-diphenol binding Agaricus bisporus
physiological function the enzyme is responsible for the browning of fruits, vegetables, fungi and crustaceans and is essential in the melanogenesis process of human skin pigmentation for protection from UV-induced damage. Nevertheless, its excessive accumulation can produce hyperpigmentation disorders such as freckles, solar lentigines, ephelide, and melasma Agaricus bisporus