Structural basis of type 2A von Willebrand disease investigated by molecular dynamics simulations and experiments.
Structural basis of type 2A von Willebrand disease investigated by molecular dynamics simulations and experiments.
复制标题
DOI：
10.1371/journal.pone.0045207
复制
发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Thomas WE
中科院分区：
文献类型：
--
作者：
Interlandi G;Ling M;Tu AY;Chung DW;Thomas WE
血管性血友病因子的止血功能被金属蛋白酶ADAMTS 13下调，ADAMTS 13在通常埋藏在A2结构域中的独特位点处切割。当血管性血友病因子在血液中循环时，剪切应力在野生型中诱导蛋白水解位点的暴露。A2结构域的突变增加了其对切割的敏感性，导致2A型血管性血友病。在这项研究中，分子动力学模拟表明，A2结构域展开张力下逐步通过一系列的步骤。模拟结果还表明，在A2结构域的C-末端一半中的三个2A型突变，L1657 I、I1628 T和E1638 K，使蛋白质的天然状态折叠不稳定。此外，所有三种2A型突变都通过计算机模拟降低了将C-末端螺旋6从A2结构域的其余部分解对接所需的张力，这是解折叠途径中的第一个事件。还通过模拟预测突变F1520 A、I1651 A和A1661 G使A2结构域不稳定并促进切割位点的暴露。表达重组A2结构域蛋白，并用野生型和单点突变体进行切割测定。所有三种2A型和三种预测突变中的两种均表现出ADAMTS 13切割速率增加。这些结果证实，A2结构域中螺旋6的去稳定化促进切割位点的暴露并增加ADAMTS 13的切割速率。
The hemostatic function of von Willebrand factor is downregulated by the metalloprotease ADAMTS13, which cleaves at a unique site normally buried in the A2 domain. Exposure of the proteolytic site is induced in the wild-type by shear stress as von Willebrand factor circulates in blood. Mutations in the A2 domain, which increase its susceptibility to cleavage, cause type 2A von Willebrand disease. In this study, molecular dynamics simulations suggest that the A2 domain unfolds under tensile force progressively through a series of steps. The simulation results also indicated that three type 2A mutations in the C-terminal half of the A2 domain, L1657I, I1628T and E1638K, destabilize the native state fold of the protein. Furthermore, all three type 2A mutations lowered in silico the tensile force necessary to undock the C-terminal helix 6 from the rest of the A2 domain, the first event in the unfolding pathway. The mutations F1520A, I1651A and A1661G were also predicted by simulations to destabilize the A2 domain and facilitate exposure of the cleavage site. Recombinant A2 domain proteins were expressed and cleavage assays were performed with the wild-type and single-point mutants. All three type 2A and two of the three predicted mutations exhibited increased rate of cleavage by ADAMTS13. These results confirm that destabilization of the helix 6 in the A2 domain facilitates exposure of the cleavage site and increases the rate of cleavage by ADAMTS13.
登录
查看更多内容
影响因子：
16.6
作者：
通讯作者：
--
影响因子：
20.3
作者：
Hassenpflug, WA;Budde, U;Schneppenheim, R
通讯作者：
Schneppenheim, R
影响因子：
4.1
作者：
Kalé, L;Skeel, R;Schulten, K
通讯作者：
Schulten, K
影响因子：
20.3
作者：
Luken, Brenda M.;Winn, Luke Y. N.;Crawley, James T. B.
通讯作者：
Crawley, James T. B.
影响因子：
4.4
作者：
FELLER, SE;ZHANG, YH;BROOKS, BR
通讯作者：
BROOKS, BR