L-Tyrosine → Dopachrome
Reaction equation
[NH2:1][C@H:2]([C:11]([OH:13])=[O:12])[CH2:3][C:4]1[CH:9]=[CH:8][C:7]([OH:10])=[CH:6][CH:5]=1.P([O-])([O-])([O-])=[O:15].[K+].[K+].[K+]>CS(C)=O>[CH2:3]1[C:4]2[C:9](=[CH:8][C:7]([C:6]([CH:5]=2)=[O:15])=[O:10])[NH:1][CH:2]1[C:11]([OH:13])=[O:12]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
The concentration of enzyme, substrate and inhibitor was denoted as [E], [S] and [J], respectively. 80 microliters of 0.067 M potassium phosphate buffer (pH 6.8), 40 microliters of L-tyrosine in 0.067 M potassium phosphate buffer (pH 6.8), 40 microliters of inhibitor in 5% DMSO solution, and 40 microliters of mushroom tyrosinase solution were added to a 96-well microplate, to make the final concentration of each reagent to be: 0.2 mg/ml [S], and 96 units/ml [E], with varying [I]. 5% DMSO solution instead of an inhibitor solution was added to a blank solution and adjusted to the total volume of 200 microliters as control. The assay mixture was incubated at 37° C. The amount of dopachrome produced in the reaction mixture was measured at 475 nm in a microplate reader at different time periods. The percentage of inhibition of tyrosinase activity was calculated as follows: Inhibition(%)=[(A−B)−C−D)]/(A−B)×100