MGST1, as a dopaquinone cyclase, promotes eumelanin formation.A, biosynthetic pathways leading to eumelanin and pheomelanin production. B, rate constants for the early-stage reactions. C and D, dopachrome formation from L-dopa was measured in whole cell lysates from B16 and MNT-1 cells in the presence of 5 mM GSH and recombinant MGST1 (active or inactivated). E and F, oxidation of L-dopa in the absence or presence of recombinant MGST1. ∗∗∗ indicates p < 0.0005. MGST, microsomal glutathione transferase; TYR, tyrosinase; TYRP, tyrosinase-related protein.
|