野桑蚕多酚氧化酶的部分生化特性分析  

Biochemical Characterization of Polyphenol Oxidase From Bom byx mandarina

作　　者：张永亮[1] 朱勇[1] 曾媛琴[1] 贾永红[2] 柳照应[1] 艾均文[1] 

机构地区：[1]西南大学生命科学学院农业部蚕桑学重点开放实验室 [2]廊坊师范学院生命科学系,廊坊065000

出　　处：《蚕业科学》2007年第3期374-379,共6页ACTA SERICOLOGICA SINICA

基　　金：重庆市教委基金项目(编号040208)

摘　　要：基于开发专一的酶抑制剂控制野桑蚕危害桑园的目的,采用硫酸铵分级沉淀及Sephadex G-100凝胶过滤等方法,纯化了野桑蚕(Bom byx mandarina)多酚氧化酶,纯化倍数为57.14倍。该酶对焦性没食子酸、邻苯二酚和L-多巴的米氏常数(Km)值分别为3.39、2.06和3.17 mmol/L,在pH 7.0、37℃时活性最高。利用硫脲、抗坏血酸等多种氧化酶抑制剂对该酶活性的抑制结果表明,所用抑制剂对其均有不同程度的抑制作用。此外,该酶对乙二胺四乙酸(EDTA)和金属离子比较敏感。To develop an enzymic inhibitor for the control of Bombyx mandarina in mulberry fields, the kinetic properties of polyphenol oxidase （PPO） from wild silkworm, Bombyx mandarina were studied after partial purification by saturated （NH4）2SO4 and Sephadex G-100 gel filtration. The results showed that the 57.14-fold purification was achieved from the crude enzyme. The Michaelis constants （Kin） with pyrogallol,catechol and L-dopamine （L-DOPA） three substrates were 3.39 mmol/L, 2.06 mmol/L and 3. 17 mmol/L, respectively. The optimum pH was 7.0 and the best temperature was 37 ℃ for the PPO. Studies on the effects of many inhibitors including thiourea and ascorbic acid etc. on the activity of PPO showed that all inhibitors studied revealed inhibitory activities. In addition,this enzyme is comparatively sensitive to EDTA and metal ions.

关 键 词：野桑蚕 多酚氧化酶 生化性质 

分 类 号：S885.9[农业科学—特种经济动物饲养]