Evidence for the Misfolding of the A1 Domain within Multimeric von Willebrand Factor in Type 2 von Willebrand Disease.
Evidence for the Misfolding of the A1 Domain within Multimeric von Willebrand Factor in Type 2 von Willebrand Disease.
复制标题
2 型冯维勒布兰德病多聚体冯维勒布兰德因子中 A1 结构域错误折叠的证据。
DOI：
10.1016/j.jmb.2019.09.022
复制
发表时间：
2020
影响因子：
5.6
通讯作者：
中科院分区：
文献类型：
--
作者：
Tischer,Alexander;Brehm,MariaA;Machha,VenkataR;Moon-Tasson,Laurie;Benson,LindaM;Nelton,KatelynnJ;Leger,RachelR;Obser,Tobias;Martinez-Vargas,Marina;Whitten,StevenT;Chen,Dong;Pruthi,RajivK;Bergen3rd,HRobert;Cruz,MiguelA;
血管性血友病因子(VWF)是一种非常大的多聚体血浆糖蛋白，通过将血流中的血小板凝集到血管损伤部位而启动凝血。在von Willebrand病的2型功能障碍亚型中，这种主要止血功能受到突变的干扰，这些突变改变了血小板GPIBα粘附性VWF A1结构域的结构和功能。由此产生的氨基酸替换导致局部紊乱，并在功能获得(2B型)和功能丧失(2M型)表型中错误折叠vWF的分离的血小板GPIBα-粘附性A1结构域的天然结构。这些结构效应还没有在血浆固有的VWF多聚体的A1结构域中明显观察到。应用新的质谱学策略来解决VWF中2B和2M突变的结构效应，以验证携带2型VWD突变的多聚体VWF中存在A1结构域结构紊乱。有限胰酶裂解质谱仪(LTMS)和氢-氚交换质谱仪(HXMS)用于单个A1、A2和A3结构域的野生型和VWD变体、VWF的A1A2A3三结构域片段、VWF的纤溶酶裂解二聚体、多聚体重组VWF和正常VWF血浆浓缩物。相比之下，这些方法表明，已知的错误折叠分离的A1结构域的突变增加了胰酶分解的速度和多聚体VWF中A1局部二级结构中氢-氚交换的程度。VWD突变效应局限于A1结构域，对其他VWF结构域的结构和动力学没有明显影响。在VWF重组片段中观察到的A1的内在动力学在血浆来源的VWF中是保守的。这些研究表明，在多聚体VWF中A1结构域的VWD变体中确实发生了结构紊乱，并为VWF的错误折叠提供了强有力的支持，这是一些(但不是全部)2型VWD变体的结果。
Von Willebrand factor (VWF), an exceptionally large multimeric plasma glycoprotein, functions to initiate coagulation by agglutinating platelets in the blood stream to sites of vascular injury. This primary hemostatic function is perturbed in type 2 dysfunctional subtypes of von Willebrand disease (VWD) by mutations that alter the structure and function of the platelet GPIbα adhesive VWF A1 domains. The resulting amino acid substitutions cause local disorder and misfold the native structure of the isolated platelet GPIbα–adhesive A1 domain of VWF in both gain-of-function (type 2B) and loss-of-function (type 2M) phenotypes. These structural effects have not been explicitly observed in A1 domains of VWF multimers native to blood plasma. New mass spectrometry strategies are applied to resolve the structural effects of 2B and 2M mutations in VWF to verify the presence of A1 domain structural disorder in multimeric VWF harboring type 2 VWD mutations. Limited trypsinolysis mass spectrometry (LTMS) and hydrogen-deuterium exchange mass spectrometry (HXMS) are applied to wild-type and VWD variants of the single A1, A2, and A3 domains, an A1A2A3 tridomain fragment of VWF, plasmin-cleaved dimers of VWF, multimeric recombinant VWF, and normal VWF plasma concentrates. Comparatively, these methods show that mutations known to misfold the isolated A1 domain increase the rate of trypsinolysis and the extent of hydrogen-deuterium exchange in local secondary structures of A1 within multimeric VWF. VWD mutation effects are localized to the A1 domain without appreciably affecting the structure and dynamics of other VWF domains. The intrinsic dynamics of A1 observed in recombinant fragments of VWF are conserved in plasma-derived VWF. These studies reveal that structural disorder does occur in VWD variants of the A1 domain within multimeric VWF and provides strong support for VWF misfolding as a result of some, but not all, type 2 VWD variants.