食品科学 ›› 2012, Vol. 33 ›› Issue (7): 223-227.doi: 10.7506/spkx1002-6630-201207047

• 生物工程 • 上一篇    下一篇

苦荞芦丁水解酶的最适作用条件及Cu2+对酶活性的抑制

崔晓东,王转花*   

  1. 化学生物学与分子工程教育部重点实验室,山西大学生物技术研究所
  • 出版日期:2012-04-15 发布日期:2012-04-20
  • 基金资助:
    国家自然科学基金项目(30970611;31171659);山西省科技攻关计划项目(20100321101); 太原市大学生创新创业人才项目 (110148025)

Optimum Reaction Conditions for Rutin-Hydrolysis Enzyme (RHE) from Tartary Buckwheat Seeds and Inhibitory Effect of Cu2+ on Its Activity

CUI Xiao-dong,WANG Zhuan-hua*   

  1. (Key Laboratory of Chemical Biology and Molecular Engineering, Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China)
  • Online:2012-04-15 Published:2012-04-20

摘要: 干燥的苦荞麦种子粉碎后经20mmol/L的醋酸盐缓冲液抽提,Resource Q和Superdex G75 HR 10/300凝胶柱分离纯化,得到一种芦丁水解酶,测定该酶的最适作用条件,研究Cu2+对该酶的抑制作用。结果表明:苦荞芦丁水解酶的分子质量约70kD,最适作用pH值为5.0。反应体系选择20%乙醇时,可保留酶的活性不被抑制,当乙醇体积分数大于50%时,对酶的活性抑制率达90%以上,表明可选用低体积分数乙醇作为芦丁的溶剂,用于芦丁水解酶测活体系及后续槲皮素制备研究。荧光光谱表明,Cu2+与芦丁水解酶以物质的量比1:1的形成稳定的复合物,可以使酶的荧光发生猝灭,水解芦丁的活性降低。表明Cu2+对芦丁水解酶有抑制作用。

关键词: 苦荞, 槲皮素, 芦丁水解酶, 荧光光谱

Abstract: A rutin-hydrolysis enzyme (RHE) was isolated from Fagopyrum tataricum (tartary buckwheat) seeds by extraction with 20 mmol/L acetate buffer acetate buffer, ammonium acetate fractionation, anion exchange chromatography and size exclusion chromatography. The molecular weight of RHE, as determined by SDS-PAGE, was 70 kD. The optimum hydrolysis pH was 5.0. The activity was not inhibited by an ethanol concentration of 20% in the reaction system, but an inhibitory rate above 90% was observed when ethanol concentration was higher than 50%. Fluorescence spectroscopic analysis indicated that Cu2+ could be bound to RHE at a molar ratio of 1:1 to generate a stable complex without fluorescence. Meanwhile, Cu2+ revealed an obvious inhibitory effect on the activity of RHE. These investigations provided a theoretical basis for future enzymatic preparation of quercetin.

Key words: tartary buckwheat, quercetin, rutin-hydrolysis enzyme, fluorescence spectrum

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