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农学学报

农学学报 ›› 2011, Vol. 1 ›› Issue (7): 1-5.

所属专题： 生物技术

• 农艺科学 生理生化 •    下一篇

枇杷果肉漆酶酶学特性研究

黄志明 陈宇 刘行侠 吴锦程   

  • 收稿日期:2011-05-18 修回日期:2011-08-04 出版日期:2011-09-26 发布日期:2011-09-26
  • 基金资助:

    福建省自然科学基金项目

Study on Characteristics of Laccase from Eriobotrya japonica Pulp

  • Received:2011-05-18 Revised:2011-08-04 Online:2011-09-26 Published:2011-09-26

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摘要：

研究枇杷果肉漆酶（EC 1.10.3.2）的提取及其理化性质，为探讨漆酶在冷藏枇杷果实木质化败坏中的作用机理提供参考。以‘解放钟’枇杷（Eriobotrya japonica Lindl.‘Jiefangzhong’）果实为试材，采用硫酸铵盐析、透析和DEAE-纤维柱层析等提取漆酶（EC 1.10.3.2）研究其理化特性，包括温度、pH、抑制物、金属离子对漆酶活性的影响及其底物特性，测定果实贮藏期间pH变化。结果表明，漆酶的最适温度为45℃，最适pH为4.4，pH为3.2~4.4时酶的稳定性较好。金属离子Cu2+、K+对漆酶有激活作用，而Ag+、Fe2+、Fe3+起抑制作用。EDTA和L-半胱氨酸抑制物对漆酶均有抑制作用，以L-半胱氨酸抑制作用最强。枇杷果肉漆酶以2,2’-连氮-双(3-乙基苯并噻唑-6-磺酸)（简称ABTS）为底物的Km值为0.00512 mol/L。

关键词: 茄子, 茄子, 种子休眠, 赤霉素, 种子萌发, 农艺性状

Abstract:

Study on extraction and physical-chemical properties of Laccase (EC 1.10.3.2) from Eriobotrya japonica pulp, in order to establish the foundation for discussion on flesh woodiness mechanism of laccase in loquat fruits under low temperature storage. Laccase in Eriobotrya japonica Lindl. ‘Jiefangzhong’ was extracted and purified by (NH4)2SO4 salting out, dialysis and DEAE-cellulose column chromatography. The influences of different temperature, pH, substrate, inhibitor and metal ions on the activity of laccase were studied. The changes of pH were determined in loquat fruits during storage. The results showed that the optimal temperature of laccase was 4.4, and optimal pH was 45℃. The enzyme activity was stable in the pH range of 3.2-4.4. The laccase activity was increased by the addition of Cu2+ and K+, while it was inhibited by the addition of Ag+, Fe2+ and Fe3+. Both EDTA and L-cysteine had an inhibitory effect on the laccase activity, and L-cysteine was the strongest one. The Km constants based on the substrate of 2,2-azobis(3-ethylbenzothiazole-6-sulfonaic acid) (ABTS) was 0.00512 mol/L .