Inhibitory effects of 4-vinylbenzaldehyde and 4-vinylbenzoic acid on the activity of mushroom tyrosinase |
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Authors: | Kang-Kang Song Qin Wang Ling Qiu Huang Huang |
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Affiliation: | The key Laboratory of Ministry of Education for Cell Biology and Tumor Cell Engineering, School of Life Sciences, Xiamen University, Xiamen, 361005, P. R.China |
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Abstract: | Tyrosinase (EC 1.14.18.1) catalyzes both the hydroxylation of tyrosine into o-diphenols and the oxidation of o-diphenols into o-quinones which form brown or black pigments. Here, the inhibitory effects of 4-vinylbenzaldehyde and 4-vinylbenzoic acid on the activity of mushroom tyrosinase have been investigated. The results showed that both 4-vinylbenzaldehyde and 4-vinylbenzoic acid could inhibit both monophenolase activity and diphenolase activity of the enzyme. For the monophenolase activity, 4-vinylbenzoic acid could lengthen the lag time, but 4-vinylbenzaldehyde could not. Both 4-vinylbenzaldehyde and 4-vinylbenzoic acid decreased the steady-state activity, and the IC50 values were estimated as 93?μM and 3.0?mM for monophenolase activity, respectively. For the diphenolase activity, the inhibitory capacity of 4-vinylbenzaldehyde was stronger than that of 4-vinylbenzoic acid, and the IC50 values were estimated as 23?μM and 0.33?mM, respectively. Kinetic analyses showed that inhibition by both compounds was reversible and their mechanisms were mixed-II type; their inhibition constants were also determined and compared. |
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Keywords: | Tyrosinase monophenolase activity diphenolase activity 4-Vinylbenzaldehyde 4-Vinylbenzoic acid inhibition kinetics |
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