Tyrosinase is a key enzyme in melanogenesis. Generally, mushroom tyrosinase from A. bisporus had been used as a model in skin-whitening agent tests employed in the cosmetic industry. The recently obtained crystal structure of bacterial tyrosinase from B. megaterium has high similarity (33.5%) to the human enzyme and thus it was used as a template for constructing of the human model. Binding of ...

Tyrosinase and tyrosinase-related protein-1 (TRP-1) are two melanogenic enzymes that regulate melanin biosynthesis. Both are glycoproteins and belong to the TRP-1 gene family. They share a significant level of sequence similarity in several regions, including the catalytic domain and the potential N-glycosylation sites. We have recently shown that inhibition of the early steps of N-glycan proce...

1. Purified pro-tyrosinase from epidermis of the frog Rana esculenta ridibunda can be activated in vitro by several proteinases (trypsin, alpha-chymotrypsin, Pronase) and by light. 2. Both pro-tyrosinase and tyrosinase are composed of a single type of subunit having pI 7.2 and approximate molecular weights 68000 and 62000 respectively. A peptide of low molecular weight is released as a conseque...

Tyrosinase is a bifunctional enzyme which oxidizes the initial step of melanin biosynthesis, that is, conversion of tyrosine to dopa and subsequently dopa to dopaquinone. It is a glycosylated protein and a major regulator of melanogenesis. To date, many approaches have been tried to regulate tyrosinase activity and melanin content. To that end, we screened small interfering RNA sequences for se...

tyrosinase (ec: 1.14.18.1) is a copper - containing enzyme which is distributed in all domains of life such as prokaryote, eukaryote, mammals, invertebrates and plants. tyrosinase catalyzes the oxidation of monophenols to diphenols and diphenols to o-quinones . the tyrosinase crystallographic data shows two histidine -rich regions named cua and cub. a loop containing residues m374, s375 and v37...

The quality of nascent protein folding in vivo is influenced by the microdynamics of the proteins. Excessive collisions between proteins may lead to terminal misfolding, and the frequency of protein interactions with molecular chaperones determines their folding rates. However, it is unclear how immature protein dynamics are regulated. In this study, we analyzed the diffusion of immature tyrosi...

Human melanocytes from individuals with different skin types, as well as from the skin of the same individual, are heterogeneous in their melanin content. This heterogeneity may be attributed to differences in the activity and expression of the three melanogenic proteins: tyrosinase and tyrosinase-related proteins 1 and 2 (gp75 and DOPAchrome tautomerase, respectively), which in turn are affect...

Tyrosinase is a ubiquitous enzyme with diverse physiologic roles related to pigment production. Tyrosinase inhibition has been well studied for cosmetic, medicinal, and agricultural purposes. We simulated the docking of tyrosinase and D-(-)-arabinose and found a binding energy of -4.5 kcal/mol for theup-formof D-(-)-arabinose and -4.4 kcal/mol for thedown-form of D-(-)-arabinose. The results of...

2,3,5,4'-Tetrahydroxystilbene-2-O-β-D-glucopyranoside (1), isolated from Polygonum multiflorum, is a noncompetitive inhibitor of tyrosinase in cell-free kinetics; it reduced the Vmax values in a dose-dependent manner. Compound 1 inhibited PKA-induced melanogenesis, reduced the protein expression of tyrosinase and its transcription factor, the microphthalmia-associated transcription factor, and ...

Purpose: To investigate the tyrosinase inhibitory activity and thermostability of weak acid-treated Sophora japonica L. flavonoid complex (SJ-FC) in different solutions. Methods: The flavonoid complex of S. japonica was isolated and treated with weak acid to generate SJ-FC. The anti-tyrosinase activities of SJ-FC and well-known tyrosinase inhibitors were compared by mushroom tyrosinase activity...