食品科学

• 生物工程 • 上一篇    下一篇

香菜叶多酚氧化酶的分离纯化与部分酶学性质研究

孙才云,方 玲,唐云明*   

  1. 西南大学生命科学学院,重庆市甘薯工程研究中心,三峡库区生态环境教育部重点实验室,重庆 400715
  • 出版日期:2015-04-15 发布日期:2015-05-05

Isolation, Purification and Enzymatic Characterization of Polyphenol Oxidase from Coriander Leaves

SUN Caiyun, FANG Ling, TANG Yunming*   

  1. Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Chongqing Sweet-Potato Engineering
    Research Center, School of Life Science, Southwest University, Chongqing 400715, China
  • Online:2015-04-15 Published:2015-05-05

摘要:

新鲜香菜叶经匀浆、缓冲液提取、硫酸铵分级沉淀、DEAE-Sepharose离子交换层析、Superdex-200凝胶过滤层析,获得电泳纯的多酚氧化酶。该酶比活力达到5 622.95 U/mg,酶活回收率为3.90%,纯化倍数为126.08;全酶分子质量为111.10 kD,亚基分子质量为55.60 kD;最适温度为37 ℃,最适pH值为6.5;在25~45 ℃及pH 6.0~7.0范围内有较好的稳定性;在最适条件下测得其Km值为4.04×10-2 mol/L;甲醇、乙醇、异丙醇、氯仿及柠檬酸、抗坏血酸、Ca2+、Hg2+、Ba2+对其有抑制作用,Co2+、Pb2+对其具有一定的激活作用。

关键词: 香菜叶, 多酚氧化酶, 分离纯化, 性质

Abstract:

Electrophoretically pure polyphenol oxidase (PPO) from fresh coriander leaves was obtained through
homogenization, buffer solution extraction, ammonium sulfate precipitation, DEAE-Sepharose ion exchange chromatography
and Superdex-200 gel filtration chromatography. The specific activity of purified PPO was 5 622.95 U/mg with a recovery of
3.90% and a purification factor of 126.08. The molecular weights of this enzyme and its subunits were 111.10 and 55.60 kD,
respectively. It was relatively stable in the range of 25–45 ℃ and pH 6.0–7.0. Its optimum temperature and pH were 37 ℃
and 6.5, respectively. Furthermore, its Km was 4.04 × 10-2 mol/L under the optimum conditions. Its activity was inhibited by
methanol, ethanol, isopropanol, trichloromethan, citric acid and ascorbic acid as well as some metal ions such as Ca2+, Hg2+
and Ba2+, but was activated by Co2+ and Pb2+.

Key words: coriander leaves, polyphenol oxidase, isolation and purification, characterization

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