波谱学杂志

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蝎毒素LmKTT-1a 与胰蛋白酶相互作用研究

罗 凡 1,2,陈宗运3,吴英亮3,蒋滨 1,姜凌 1*,刘买利1   

  1. 1. 波谱与原子分子物理国家重点实验室,武汉磁共振中心(中国科学院武汉物理与数学研究所),湖北 武汉 430071;
    2. 中国科学院大学,北京100049;
    3. 病毒学国家重点实验室,武汉大学生命科学学院,湖北武汉 430072
  • 收稿日期:2013-04-11 修回日期:2013-04-17 出版日期:2014-03-05 发布日期:2014-03-05
  • 作者简介:罗凡(1985-),男,湖北人,博士研究生,从事蛋白溶液结构的核磁共振研究. *通讯联系人:姜凌,电话:027-87198493, E-mail: lingjiang@wipm.ac.cn.
  • 基金资助:

    国家自然科学基金资助项目(21173257, 21005085, 31200557).

Interaction between LmKTT-1a and Trypsin Studied by NMR Spectroscopy

LUO Fan1,2,CHEN Zong-yun3,WU Ying-liang3,JIANG Bin1,JIANG Ling1*,LIU Mai-li1   

  1. 1. State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance(Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences), Wuhan 430071, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China;
    3. State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
  • Received:2013-04-11 Revised:2013-04-17 Online:2014-03-05 Published:2014-03-05
  • About author:*Corresponding author: JIANG Ling, Tel: 027-87198493, E-mail: lingjiang@wipm.ac.cn.
  • Supported by:

    国家自然科学基金资助项目(21173257, 21005085, 31200557).

摘要:

LmKTT-1a 是最近发现的一个蝎毒素,该多肽分子不仅具有钾离子通道调节剂的功能,还具有胰蛋白酶(Trypsin)抑制剂的活性,是第一个被发现的双功能蝎毒素.虽然前期工作已对LmKTT-1a 的溶液结构和钾离子通道调节剂的功能进行了研究,但未阐明LmKTT-1a 和Trypsin 的作用方式和位点.文中利用液体NMR 的手段,采用化学位移扰动分析的方法,确定了LmKTT-1a 的loop 区域V10~F17 等氨基酸位点可能参与了与Trypsin的相互作用.进一步采用定点突变的方法验证了NMR 实验的结果,并确认了LmKTT-1a与Trypsin 相互作用最关键的氨基酸位点是K14.该研究结果有助于进一步理解LmKTT-1a具有双功能活性的结构基础.

关键词: 核磁共振(NMR), 相互作用, 化学位移扰动分析, 蝎毒素, LmKTT-1a, 胰蛋白酶

Abstract:

LmKTT-1a is a dual-functional toxin recently discovered in scorpion venom glands. It has both protease and potassium ion channel inhibiting properties. Preliminary work has determined the solution structure of LmKTT-1a and evaluated its potassium ion channel inhibition function. In this study, NMR techniques and chemical shift perturbation analysis were used to identify the interaction interface between LmKTT-1a and the protease Trypsin. The residues of V10 to F17 in the loop region of LmKTT-1a was found to be the crucial binding sites. The NMR results were confirmed by a serious of mutations and enzymatic assays, and we found that K14 is the most pivotal residue in the interaction between Trypsin and LmKTT-1a. This work helped to further understand the structural-function relationship of LmKTT-1a.

Key words: NMR, interaction, chemical shift perturbation analysis, scorpion toxin, LmKTT-1a, trypsin

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