Study of the inhibition of 3-/4-aminoacetophenones on tyrosinase
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- 作者：Antonio Garcia-Jimenez…
- 关键词：3 ; Aminoacetophenone ; 4 ; Aminoacetophenone ; Tyrosinase ; Activation ; Inhibition
- 刊名：Reaction Kinetics, Mechanisms and Catalysis
- 出版年：2017
- 出版时间：February 2017
- 年：2017
- 卷：120
- 期：1
- 页码：1-13
- 全文大小：
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Catalysis; Physical Chemistry; Industrial Chemistry/Chemical Engineering;
- 出版者：Springer Netherlands
- ISSN：1878-5204
- 卷排序：120
文摘
When the action of tyrosinase on l-dopa in the presence of 3-aminoacetophenone is studied, inhibition or activation is observed depending on the concentration of substrate. These opposing effects are due to non-enzymatic reactions: when tyrosinase acts on l-dopa, a highly reactive molecule, o-dopaquinone, originates, which evolves to dopachrome; in the presence of 3-/4-aminoacetophenones, the amino group of these compounds nucleophilically attacks the o-quinones, generating a colorless adduct, which, in turn, is oxidized by another molecule of o-dopaquinone, giving a colored compound with an absorbance higher than that of the dopachrome in an apparent activating effect. Therefore, an apparent activation or inhibition is seen depending on the concentration of l-dopa used in the experiments. Moreover, docking studies showing the binding mode of these molecules to the met (Em) and oxy (Eox) forms of tyrosinase reveal that both compounds arranges itself in the active centre in a similar way to monophenolic substrates of the enzyme, confirming the inhibition of the enzyme. We proposed a kinetic test to elucidate whether a compound is a true activator or an inhibitor of tyrosinase.