食品科学

• 生物工程 • 上一篇    下一篇

青蒿多酚氧化酶的酶学特性研究

田国政,程 超,田 莉,牟 迪,周毅峰   

  1. 1.湖北民族学院生物科学与技术学院,湖北 恩施 445000;2.生物资源保护与利用湖北省重点实验室,湖北 恩施 445000;3.湖北民族学院林学园艺学院,湖北 恩施 445000
  • 出版日期:2014-10-15 发布日期:2014-10-17

Enzymatic Properties of Polyphenol Oxidase in Artemisia carvifolia

TIAN Guo-zheng, CHENG Chao, TIAN Li, MOU Di, ZHOU Yi-feng   

  1. 1. College of Biological Science and Technology, Hubei Minzu University, Enshi 445000, China;
    2. Key Laboratory of Biologic Resources Protection and Utilization of Hubei Province, Enshi 445000, China;
    3. College of Forestry and Horticulture, Hubei Minzu University, Enshi 445000, China
  • Online:2014-10-15 Published:2014-10-17

摘要:

以新鲜青蒿为材料,考察不同温度、pH值、底物浓度、激活剂、抑制剂对青蒿多酚氧化酶(polyphenoloxidase,PPO)活性的影响。结果表明:温度和pH值对酶活性的影响均存在一个最适值,分别为40 ℃和6.8;在一定底物浓度范围内,酶促反应速率随底物浓度的增加而增大,其米氏常数(Km)为0.015 4 mol/L,最大反应速率(Vmax)为125 U/min;MgC12、SDS对青蒿PPO活性有一定激活作用,当MgC12浓度为0.9 mmol/L、SDS浓度为8 mmol/L时,青蒿PPO活性分别高出对照组30.3%和45.3%;当VC质量浓度为0.03 g/L、柠檬酸质量浓度为1.2 g/L、PVP质量浓度为20 g/L时抑制率分别为70.4%、83.7%、77.6%;NaHSO3在0.01~0.08 mmol/L的浓度范围内对青蒿PPO抑制作用缓慢上升。

关键词: 青蒿, 多酚氧化酶, 酶促动力学

Abstract:

The study was performed to explore the effects of temperature, pH, substrate concentration, activator, and
inhibitor on PPO activity of Artemisia apiacea. Experimental results showed that the optimal pH and temperature for PPO
activity were 40 ℃ and 6.8, respectively. The Michaelis constant (Km) was 0.015 4 mol/L and Vmax was 125 U/min, which
was increased along with an increase in substrate concentration in a certain range. As compared with the control, MgCl2 and
SDS activated PPO activity by 30.3% and 45.3% when added at a concentration of 0.9 and 8 mmol/L, respectively. VC,
citric acid and PVP inhibited the enzyme activity by 70.4%, 83.7% and 77.6% when used at a concentration of 0.03, 1.2 and
20 g/L, respectively. The inhibition of NaHSO3 on PPO activity rose slowly with increasing concentration from 0.01 to 0.08 mmol/L.

Key words: Artemisia apiacea, polyphenol oxidase, enzymatic kinetics

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