Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (01): 215-220.doi: 10.3866/PKU.WHXB20100115

• BIOPHYSICAL CHEMISTRY • Previous Articles     Next Articles

Inhibitory Kinetics of a Trifluoromethyl-Containing 1,2,3-Triazole Derivative on Mushroom Tyrosinase Activity

LI Shu-Bai, NIE Hua-Li, ZHANG Hai-Tao, XUE Yong, CHRIS Branford White, ZHU Li-Min   

  1. College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, P. R. China; Institute for Health Research and Policy, London Metropolitan University, London N7 8DB, UK
  • Received:2009-06-18 Revised:2009-10-28 Published:2009-12-29
  • Contact: ZHU Li-Min E-mail:lzhu@dhu.edu.cn

Abstract:

 In this study, we demonstrate that the trifluoromethyl-containing 1,2,3-triazole derivative (TF-TZ) inhibits mushroom tyrosinase. TF-TZ could inhibit the monophenolase and diphenolase activities and the inhibition is reversible. IC50 values of 30.4 and 34.5 μmol·L-1 were estimated for the monophenolase activity and the diphenolase activity, respectively. TF-TZ could extend the lag period of the monophenolase activity. Kinetic analysis showed that parabolic-competitive inhibition of TF-TZ occurred on diphenolase. We proposed that two TF-TZ molecules combined with free tyrosinase to formenzyme-inhibitor complexes (EI and EI2), and the inhibition constants (Ki1 for EI and Ki2 for EI2) were 76.9 and 9.71 μmol·L-1, respectively. Moreover, the UV-Visible spectrum of a mixture of tyrosinase and TF-TZ exhibited a characteristic shoulder peak that could be assigned to chelation of TF-TZ to the active site.

Key words: Trifluoromethyl-containing 1,2,3-triazole, Mushroomtyrosinase, Monophenolase, Diphenolase, Reversible parabolic-competitive inhibition, Copper chelation

MSC2000: 

  • O643