Kinetics of inhibitory effect of isoferulic acid on mushroom tyrosinase.
A study on the kinetics of inhibitory effect of isoferulic acid on the monophenolase and diphenolase activity of mushroom tyrosinase was carried out using enzymological kinetic analysis method in a Na2HPO4-NaH2PO4 buffer solution (pH = 6.8) at 30°C. It was found that isoferulic acid efficiently inhibits both monophenolase and diphenolase activities of mushroom tyrosinase under experimental conditions. Concentrations of isoferulic acid leading to 50% rate inhibition (IC50) on monophenolase and diphenolase activity were calculated to be 0.13 mmol/L and 0.39 mmol/L, respectively, which are much lower than that of arbutin (IC50 = 5.3 mmol/L for diphenolase activity). The presence of isoferulic acid also prolongs the lag period in the oxidation process of l-tyrosine via tyrosinase-a 4.3-min lagging was observed with the presence of 0.20 mmol/L isoferulic acid-compared to a 1.1-min lagging in the absence of isoferulic acid. The Lineweaver-Burk plot demonstrates a competitive behavior of isoferulic acid in the tyrosinase oxidation of l-3,4-dihydroxyphenylalanine, with maximum reaction rate (vm) and inhibition constant (KI) at 64.5 µM/min and 0.11 mmol/L, respectively.
Department of Chemical Engineering, Guangdong Industry Technical College, Guangzhou, China. 1996103022@gditc.edu.cn
Shengzhao
S
Gong
Meijuan
M
Yin
Zhimian
Z
Yun
D000363:Agaricales / Q000201:enzymology*; D031885:Cimicifuga / Q000737:chemistry; D002934:Cinnamates / Q000737:chemistry / Q000494:pharmacology*; D007700:Kinetics; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors*; D027343:Rhizome / Q000737:chemistry
D002934:Cinnamates; D014442:Monophenol Monooxygenase; C008180:isoferulic acid