Short-Sequence Oligopeptides with Inhibitory Activity against Mushroom and Human Tyrosinase

Abstract

Cutaneous hyperpigmentation is a common disorder due to excess melanin production by the enzyme tyrosinase. The gold standard for treatment is hydroquinone (HQ), which reduces pigmentation through its toxicity to melanocytes rather than via tyrosinase inhibition. We screened an internal library for oligopeptides that inhibited both mushroom and human tyrosinase but showed no cytotoxicity to human melanocytes. We identified two highly active inhibitory sequences, P3 and P4, of 8- and 10-amino-acid-length, respectively. Mushroom tyrosinase inhibition was dose-dependent with IC(50) (half-maximal inhibitory concentration) values of 123 and 40 microM, respectively, compared with 680 microM for HQ. Other oligopeptides showed weaker or no inhibitory activity. Kinetic studies showed that P3 and P4 are competitive inhibitors of mushroom tyrosinase. At 100 microM, P3 and P4 inhibited human tyrosinase by 25-35%. This inhibition partially depended on whether L-dopa or L-tyrosine was the substrate, suggesting that tyrosinase may contain contains two distinct catalytic sites. Treatment of melanocytes with 100 microM P3 or P4 for 7 days led to a 27 or 43% reduction in melanin content. This inhibition was independent of cell proliferation and cytotoxic effects. Our data suggest that peptide-mediated inhibition of melanogenesis is due to reduction in tyrosinase activity.

Phage Display–Mediated Discovery of Novel Tyrosinase-Targeting Tetrapeptide Inhibitors Reveals the Significance of N-Terminal Preference of Cysteine Residues and Their Functional Sulfur Atom

“…Thus, several studies made efforts to find novel proteins and peptides from natural resources, such as silk (Kato et al, 1998), milk (Nakajima et al, 1996;Chen et al, 2006), honey (Oszmianski, 1990;Ates and Cokmus, 2001), wheat (Okot-Kotber et al, 2001), and the housefly (Daquinag et al, 1995(Daquinag et al, , 1999, for tyrosinase inhibition. On top of that, dipeptides (Girelli et al, 2004), kojic acid tripeptides (Noh et al, 2007), mimosine tetrapeptides (Upadhyay et al, 2011), cyclic peptides (Morita et al, 1994), short-sequence oligopeptides (Abu Ubeid et al, 2009), and octameric peptides (Schurink et al, 2007) were also investigated for their tyrosinase-inhibitory abilities. Herein without precedent, we systematically and comprehensively investigated C-and N-terminal cysteine/tyrosine-containing tetrapeptides for tyrosinase inhibition and found that the CRVI tetrapeptide showed the strongest mushroom tyrosinase-inhibitory potency.…”

Discovery of Potent Cysteine-Containing Dipeptide Inhibitors against Tyrosinase: A Comprehensive Investigation of 20 × 20 Dipeptides in Inhibiting Dopachrome Formation

“…Therefore, continual efforts have been exerted to obtain tyrosinase inhibitors synthetically (in laboratories) 24−26 and naturally (through plant extractions). 27−29 Recently, we used phage-displayed tetrapeptide inhibitors 30 and a T1 compound from Gastrodia elata, 31 and other researchers have employed peptide-derived compounds for tyrosinase inhibition. 4,32,33 Certain short-sequence oligopeptides, P3 and P4, inhibit mushroom tyrosinase with no cytotoxicity to human melanocyte.…”

Melasma, Novel Treatment Modalities

“…The aim was to produce oligopeptides with high tyrosinase inhibiting activity, that are neither cytotoxic nor mutagenic A number of peptide fragments have been shown to reduce pigment production [42][43][44].…”