Institute of Biochemical Sciences, National Taiwan University, Taipei 10617, Taiwan.
Toxicon. 2013 Sep;71:140-6. doi: 10.1016/j.toxicon.2013.05.009. Epub 2013 May 31.
The crystal structure of TM-1, a P-I class snake-venom metalloproteinase (SVMP) from the Trimeresurus mucrosquamatus venom, was determined at 1.8-Å resolution. The structure exhibits the typical feature of SVMPs and is stabilized by three disulfide linkages. The active site shows a deep S1' substrate-binding pocket limited by the non-conserved Pro174 at the bottom. Further comparisons with other SVMPs suggest that the deep S1' site of TM-1 correlates with its high inhibition sensitivity to the endogenous tripeptide inhibitors. Proteolytic specificity analysis revealed that TM-1 prefers substrates having a moderate-size and hydrophobic residue at the P1' position, consistent with our structural observation.
来自竹叶青蛇毒液的 TM-1，一种 P-I 类蛇毒金属蛋白酶（SVMP）的晶体结构被解析到 1.8Å 分辨率。该结构表现出 SVMP 的典型特征，并由三个二硫键稳定。活性位点显示出一个深的 S1'底物结合口袋，由底部的非保守 Pro174 限制。与其他 SVMP 的进一步比较表明，TM-1 的深 S1'位点与其对内源性三肽抑制剂的高抑制敏感性相关。蛋白水解特异性分析表明，TM-1 优先选择 P1'位置具有中等大小和疏水性残基的底物，与我们的结构观察结果一致。
