Pigmentation of the skin, hair and eyes is regulated by tyrosinase, the critical rate-limiting enzyme in melanin synthesis by melanocytes. Tyrosinase is degraded endogenously, at least in part, by the ubiquitin proteasome system (UPS). Several types of inherited hypopigmentary diseases, such as oculocutaneous albinism and Hermansky-Pudlak syndrome, involve the aberrant processing and/or traffic...

Tyrosinase was found to catalyze the oxidation of phenylhydrazine to phenol in a reaction that did not resemble those typically performed by tyrosinase. The kinetics of this reaction was investigated by measuring the initial velocity of the formation of phenol (25 °C). The values of k cat and K M for the oxidation of phenylhydrazine were obtained as 11.0 s(-1) and 0.30 mM, respectively. The gen...

Dopamine is one of the important medications of Portulaca oleracea L. To optimize the production of dopamine, one of the methods is the identification and engineering of metabolite pathways. To investigate the tyrosine decarboxylase (TDC) and tyrosinase, which seem to be the most important genes in dopamine synthesis pathway, hairy roots were produced from Portulaca oleracea using Agrobacterium...

Anisaldehyde (4-methoxybenzaldehyde), previously reported as a tyrosinase inhibitor, did not inhibit melanogenesis in cultured B16-F10 melanoma cells but rather enhanced it. This adverse effect of anisaldehyde was accompanied by melanocytotoxicity in a dose-dependent manner up to 2 mM. The melanin content per cell at 1 mM was increased 5-fold compared to control and morphological observations s...

Since the discovery of Cu(I)-catalysed click chemistry, the field of peptidomimetics has expanded to include 1,4-connected 1,2,3-triazoles as useful peptide bond isosteres. Here, we report the synthesis of triazole-containing analogues of the naturally occurring tyrosinase inhibitor cyclo-[Pro-Val-Pro-Tyr] and show that the analogues retain enzyme inhibitory activity, demonstrating the effectiv...

In mammalian melanocytes, melanosome is a highly specialized organelle where melanin is synthesized. Melanin synthesis is controlled by tyrosinase, the vital enzyme in melanogenic pathway. The present investigation is based on an effect of purified mushroom tyrosinase of Agaricus bisporus on B16F10 melanocytes for the melanin production via blocking pigment cell machinery. Using B16F10 melanocy...