Acta Entomologica Sinica (2005) 48, 290-294

Chao-Bin Xue, Qin Wang, Li-Na Ke, Qing-Xi Chen and Wan-Chun Luo (2005)
[Inhibitory effect of cupferron on the activity of polyphenoloxidase from Pieris rapae (L.) (Lepidoptera: Pieridae)]
Acta Entomologica Sinica 48 (2), 290-294
Abstract: The kinetic properties of polyphenoloxidase (PPO) from Pieris rapae (L.) were studied after the enzyme was partially purified by 35% saturated (NH₄)₂SO₄ and chromatographed on a Sephadex G-100 gel filtration. Meanwhile, the effects of PPO on the oxidation of L-DOPA by adding copper ion or cupferron were also studied. The results showed that the activity of PPO was enhanced by Cu₂₊ in the concentration of 0-0.100 mmol/L; however, the activity was inhibited by the same ion when the concentration was over 0.125 mmol/L, and the IC₅₀ was estimated to be 0.651±0.022 mmol/L. The results also indicated that the reaction of cupferron with the PPO is a reversible course with remaining enzyme activity, the inhibitory mechanism belongs to be the competitive type and the IC₅₀ was estimated to be 0.100±0.012 mmol/L. Furthermore, the equilibrium constant for cupferron was determined to be 0.076±0.013 mmol/L.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: Chinese)
Database assignments for author(s): Chao-Bin Xue, Wan-Chun Luo

Research topic(s) for pests/diseases/weeds:
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Pieris rapae