食品科学

• 生物工程 • 上一篇    下一篇

热处理对蘑菇多酚氧化酶活性及结构的影响

周 磊,邹立强,刘 伟*,方志超,刘军平   

  1. 南昌大学 食品科学与技术国家重点实验室,江西 南昌 330047
  • 出版日期:2014-09-15 发布日期:2014-09-12

Effect of Heat Treatment on Activity and Conformation of Mushroom Polyphenol Oxidase

ZHOU Lei, ZOU Li-qiang, LIU Wei*, FANG Zhi-chao, LIU Jun-ping   

  1. State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
  • Online:2014-09-15 Published:2014-09-12

摘要:

以蘑菇多酚氧化酶(polyphenol oxidase,PPO)为原料,研究不同温度热处理对PPO活性的影响。选取不同温度(50、55、60、65 ℃)处理10 min后的PPO样液,应用圆二色光谱(circular dichroism,CD)和荧光光谱研究热处理对PPO二级结构和三级结构的影响。结果表明:在各温度下进行热处理的PPO活性均随着处理时间的延长逐渐降低,热处理温度越高抑制效果越明显;CD光谱表明热处理后的PPO二级结构发生了改变,主要表现在α-螺旋含量下降,β-折叠含量升高,而β-转角及无规卷曲含量则没有太大的变化;荧光光谱表明热处理后的PPO三级结构发生改变,表现在最大荧光发射峰发生了明显红移。

关键词: 多酚氧化酶, 热处理, 二级结构, 三级结构

Abstract:

The effect of heat treatment on the relative activity of polyphenol oxidase (PPO) from mushroom was
investigated. The changes of secondary and tertiary structure of PPO after heat treatment at various temperatures (50, 55,
60 and 65 ℃) for 10 min were analyzed by circular dichroism (CD) spectroscopy and fluorescence emission spectroscopy.
The results showed that the relative activity of PPO decreased gradually with increasing treatment time at each investigated
temperature. CD spectral analysis also showed that the secondary structure of PPO was changed after the heat treatment,
which was reflected by a decrease of α-helix content and an increase of β-sheet content. However, no obvious difference was
observed for β-turn and random coil contents. Meanwhile, fluorescence emission spectral analysis showed that the tertiary
structure of PPO was changed after the heat treatment with an apparent red shift in the maximum peak wavelength.

Key words: polyphenoloxidase, heat treatment, secondary structure, tertiary structure

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