Zebrafish phosvitin-derived peptide Pt5 inhibits melanogenesis via cAMP pathway.

Zebrafish phosvitin-derived peptide Pt5, consisting of the C-terminal 55 residues of phosvitin, has been shown to have an antimicrobial-immunomodulatory activity comparable to phosvitin. Here, we showed clearly that Pt5 had the capacity to inhibit tyrosinase (TYR) activity and melanin biosynthesis, and this inhibition was independent of cell proliferation and cytotoxic effects. Incubation of fluorescein isothiocyanate (FITC)-labeled Pt5 with B16F10 melanoma cells revealed that Pt5 was localized in the cytoplasm of the cells.