高等学校化学学报 ›› 2012, Vol. 33 ›› Issue (06): 1245.doi: 10.3969/j.issn.0251-0790.2012.06.021

• 生物化学 • 上一篇    下一篇

离子液体对木瓜蛋白酶催化特性的影响

侯雪丹3, 娄文勇1,2, 颜丽强3, 宗敏华2   

  1. 1. 华南理工大学制浆造纸工程国家重点实验室, 广州 510640;
    2. 轻工与食品学院应用生物催化实验室, 广州 510640;
    3. 华南理工大学生物科学与工程学院, 广州 510006
  • 收稿日期:2011-09-06 出版日期:2012-06-10 发布日期:2012-06-10
  • 通讯作者: 娄文勇, 男, 博士, 副教授, 主要从事生物催化方面的研究; 宗敏华, 女, 博士, 教授, 博士生导师, 主要从事生物催化方面的研究. E-mail:wylou@scut.edu.cn
  • 基金资助:

    国家自然科学基金(批准号: 21072065, 20876059)、华南理工大学中央高校基本科研业务费项目(批准号: 2011ZG0018, 2009ZZ0026)、全国优秀博士学位论文作者专项资金项目(批准号: 201504)和教育部新世纪优秀人才支持计划项目(批准号: NCET-10-0367)资助.

Influences of Ionic Liquids on Catalytic Performances of Papain

HOU Xue-Dan3, LOU Wen-Yong1,2, YAN Li-Qiang3, ZONG Min-Hua2   

  1. 1. State Key Laboratory of Pulp and Paper Engineering, Guangzhou 510640, China;
    2. Lab of Applied Biocatalysis, College of Light Industry and Food Sciences, South China University of Technology, Guangzhou 510640, China;
    3. School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China
  • Received:2011-09-06 Online:2012-06-10 Published:2012-06-10

摘要: 研究了以1-丁基-3-甲基咪唑、四乙基铵及N-乙基吡啶为阳离子, 配以多种阴离子(H2PO4-, ClO4-, HSO4-, CH3COO-, Cl-, Br-, NO3-, SCN-, BF4-, PF6-)的离子液体对木瓜蛋白酶催化N-苯甲酰-L-精氨酸乙酯(BAEE)水解的活性及热稳定性的影响. 通过分析含离子液体体系中木瓜蛋白酶的水解活性和热力学失活参数, 发现该酶活性及稳定性与离子液体的Kosmotropicity性质无关. 因此, 离子的Hofmeister效应并不适合解释离子液体对木瓜蛋白酶催化特性的影响规律. 当以BF4-为阴离子, 改变阳离子结构时, 仅[BMIm][BF4]可提高酶活性, 其它含官能团的咪唑类离子液体则降低酶活性, 但大部分离子液体明显提高木瓜蛋白酶的热稳定性. 在所研究的离子液体中, 基于PF6-或BF4-阴离子的离子液体可提高木瓜蛋白酶的活性及其热稳定性. 在含[BMIm][PF6]介质中, 木瓜蛋白酶的水解活性最高; 在含[HOEtMIm][BF4]介质中其热稳定性最好.

关键词: 木瓜蛋白酶, 离子液体, Hofmeister效应, 酶活性, 酶热力学稳定性

Abstract: A series of ionic liquids(ILs) based on 1-butyl-3-methylimidazolium([BMIm]), N-ethylpyridi-nium(EPy) and tetraethylammonium([NEt4]) cations with various kinds of anions(H2PO4-, ClO4-, HSO4-, CH3COO-, Cl-, Br-, NO3-, SCN-, BF4-, PF6-) was examined for their influences on papain-mediated hydrolysis of N-benzoyl-L-arginine ethyl ester. By assaying the hydrolysis activity and thermodynamics deactivation parameters of papain in all these IL-containing systems, it was found that there was no correlation between the enzymatic activity or thermostability and the ILs kosmotropicity. Thus, the Hofmeister effect was not regarded as a good explanation for remarkable effects of ILs on catalytic performance of papain. In the case of BF4--based ILs combined with various cations, only [BMIm][BF4] enhanced the hydrolysis activity of papain, and other ILs lowered the enzymatic activity. However, most of all the tested ILs improved the enzymatic thermostability apart from the strong acidic one -[HOOCMMIm][BF4]. Among all the examined ILs, the BF4-- or PF6--based ILs markedly enhanced the activity or thermostability of papain. The enzyme exhibited the highest hydrolysis activity with [BMIm][PF6], and the best thermostability with [HOEtMIm][BF4].

Key words: Papain, Ionic liquid, Hofmeister effect, Enzyme activity, Thermostability of enzyme

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