Kinetics of Ergothioneine Inhibition of Mushroom Tyrosinase.

Liao, Wayne; Wu, Wen; Tsai, Pei-Chuan; Wang, Hui-Feng; Liu, Yi-Hsin; Chan, Chin-Feng

The native amino acid ergothioneine, a thiourea derivative of histidine, inhibits mushroom tyrosinase activity in a dose-dependent manner, with an IC value of 1.025 mg/ml (4.47 mM). By contrast, histidine exhibited no inhibitory effect on mushroom tyrosinase activity. We characterized ergothioneine as a noncompetitive tyrosinase inhibitor using a Lineweaver-Burk plot of experimental kinetic data. The IC value for ergothioneine scavenging of 2,2-diphenyl-1-picrylhydrazyl was 6.110 ± 0.305 mg/ml, much higher than the IC for inhibition of tyrosinase activity which indicating ergothioneine on tyrosinase shows a weak correlation to its antioxidative activity. The results demonstrated that ergothioneine has a potent inhibition effect on tyrosinase enzyme activity, resulting from the presence of the sulfur substituted imidazole ring in ergothioneine.

AMINO acids; HISTIDINE; PHENOL oxidase; IMIDAZOLES; SULFUR

Applied Biochemistry & Biotechnology, 2012, Vol 166, Issue 2, p259

0273-2289

Academic Journal

10.1007/s12010-011-9421-x