Exposure of Von Willebrand Factor Cleavage Site in A1A2A3-Fragment under Extreme Hydrodynamic Shear

Polymers

Simone Melchionna¹  Aleksey V. Belyaev²  Daria O. Yurkova²  Emeline Laborie³  Philippe Derreumaux³  Olivier Languin-Cattoën³  Fabio Sterpone³ 

[1]Dipartimento di Fisica, Università Sapienza, P.le A. Moro 5, 00185 Rome, Italy

[2]Faculty of Physics, Lomonosov Moscow State University, 119991 Moscow, Russia

[3]Laboratoire de Biochimie Théorique, CNRS, Université de Paris, UPR 9080, 13 rue Pierre et Marie Curie, F-75005 Paris, France

关键词: von Willebrand factor;    molecular dynamics;    coarse-grains;    lattice Boltzmann;    shear flow;    protein unfolding;   

DOI  :  10.3390/polym13223912

来源: DOAJ

【 摘 要 】

Von Willebrand Factor (vWf) is a giant multimeric extracellular blood plasma involved in hemostasis. In this work we present multi-scale simulations of its three-domains fragment A1A2A3. These three domains are essential for the functional regulation of vWf. Namely the A2 domain hosts the site where the protease ADAMTS13 cleavages the multimeric vWf allowing for its length control that prevents thrombotic conditions. The exposure of the cleavage site follows the elongation/unfolding of the domain that is caused by an increased shear stress in blood. By deploying Lattice Boltzmann molecular dynamics simulations based on the OPEP coarse-grained model for proteins, we investigated at molecular level the unfolding of the A2 domain under the action of a perturbing shear flow. We described the structural steps of this unfolding that mainly concerns the $\beta$-strand structures of the domain, and we compared the process occurring under shear with that produced by the action of a directional pulling force, a typical condition of single molecule experiments. We observe, that under the action of shear flow, the competition among the elongational and rotational components of the fluid field leads to a complex behaviour of the domain, where elongated structures can be followed by partially collapsed melted globule structures with a very different degree of exposure of the cleavage site. Our simulations pose the base for the development of a multi-scale in-silico description of vWf dynamics and functionality in physiological conditions, including high resolution details for molecular relevant events, e.g., the binding to platelets and collagen during coagulation or thrombosis.

【 授权许可】

Unknown