蒲菜多酚氧化酶的酶学性质研究

目的]研究蒲菜多酚氧化酶（PPO）的酶学性质。方法]研究蒲菜PPO的吸收光谱和动力学性质,并对温度、pH、底物浓度、抑制剂等因素对蒲菜PPO活性的影响进行探索。结果]蒲菜PPO催化邻苯二酚的产物在415 nm处有最大吸收峰,动力学方程为：V=0.982S]/（4.97＋S]）,其中,V为反应速度;S]为底物浓度。蒲菜PPO最适温度为30℃,在95℃、2 min条件下可以有效地抑制蒲菜PPO活性;蒲菜PPO最适pH为6.8,当pH（5.4或pH（7.2时可以有效降低蒲菜PPO活性;柠檬酸、亚硫酸钠、抗坏血酸、EDTA-2Na等抑制剂对PPO均有抑制作用。结论]蒲菜PPO的酶学性质研究结果可为蒲菜的研究开发提供依据。

Enzyme Property of Polyphenol Oxidase (PPO)in Typha latifolia

Objective] The enzyme Property of Polyphenol Oxidase in Typha latifolia was studied.Methods] The absorbing band and the kinetic property of Typha latifolia PPO were researched in this paper.And the effects of temperature,pH,substrate concentration and inhibition on PPO activity were also studied.Results] The biggest absorption peaks of PPO catalysis pyrocatecho was 415 nm.The kinetic equation was V=0.982S]/(4.97+S]).V stood for reaction speed;S]stood for concentration of substrate.The optimum temperature of PPO was 30 ℃ and the optimum pH was 6.8.It had inhibiting effect on the activity of polyphenol oxidase when it had been heated above 95 ℃and lasted 2 min.It had inhibiting effect on the activity of PPO when pH﹤5.4 or pH﹥7.2.Citric acid,Na2SO3,ascorbic acid and EDTA-2Na can availably inhibit PPO activity.Conclusion] Results of Typha latifolia PPO enzyme property can provide scientific basis for the study and development of Typha latifolia.