蝎毒素LmKTT-1a与胰蛋白酶相互作用研究  

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

作　　者：罗凡[1,2] 陈宗运[3] 吴英亮[3] 蒋滨[1] 姜凌[1] 刘买利[1] 

机构地区：[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

出　　处：《波谱学杂志》2014年第1期100-107,共8页Chinese Journal of Magnetic Resonance

基　　金：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KI4.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.LmKTT-la 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-la 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-1 a and the protease Trypsin. The residues of V10 to F17 in the loop region of LmKTT-la 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-la. This work helped to further understand the structural-function relationship of LmKTT- la.

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 

分 类 号：O482.53[理学—固体物理]