Kojic acid, a cosmetic skin whitening agent, is a slow-binding inhibitor of catecholase activity of tyrosinase.
It was found that kojic acid, which is used in cosmetics for its excellent whitening effect, inhibits catecholase activity of tyrosinase in a non-classical manner. A decrease in the initial velocity to a steady-state inhibited velocity can be observed over a few minutes. This time-dependence, which is unaltered by prior incubation of the enzyme with the inhibitor, is consistent with a first-order transition. The kinetic data obtained correspond to those for a postulated mechanism that involves the rapid formation of an enzyme inhibitor complex that subsequently undergoes a relatively slow reversible reaction. Kinetic parameters characterizing this type of inhibition were evaluated by means of nonlinear regression of product accumulation curves.
Cabanes
J
J
Departamento de Bioquimíca y Biología Molecular A, Facultad de Veterinaria, Universidad de Murcia, Spain.
Chazarra
S
S
Garcia-Carmona
F
F
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D050482:Catecholamine Plasma Membrane Transport Proteins; D004817:Epidermis / Q000187:drug effects / Q000201:enzymology*; D007980:Levodopa / Q000378:metabolism; D026901:Membrane Transport Proteins; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors*; D009183:Mycotoxins / Q000493:pharmacokinetics / Q000494:pharmacology*; D011753:Pyrones / Q000493:pharmacokinetics / Q000494:pharmacology*; D011893:Rana esculenta; D012044:Regression Analysis; D013056:Spectrophotometry, Ultraviolet; D013379:Substrate Specificity; D013997:Time Factors
D002352:Carrier Proteins; D050482:Catecholamine Plasma Membrane Transport Proteins; D026901:Membrane Transport Proteins; D009183:Mycotoxins; D011753:Pyrones; D007980:Levodopa; C011890:kojic acid; D014442:Monophenol Monooxygenase