scholarly journals 1E02 Shear Dependent Adhesive Force between Glycoprotein Ibα and von Willebrand factor and its Conformational Change Measured by Atomic Force Microscopy

2013 ◽  
Vol 2013.25 (0) ◽  
pp. 147-148
Author(s):  
Yuichiro NISHIBUCHI ◽  
Hiroaki TOBIMATSU ◽  
Shinya GOTO ◽  
Ryo SUDO ◽  
Kazuo TANISHITA
Keyword(s):  
Atomic Force Microscopy ◽  
Conformational Change ◽  
Von Willebrand Factor ◽  
Adhesive Force ◽  
Force Microscopy ◽  
Atomic Force ◽  
Von Willebrand ◽  
Willebrand Factor

Shear and Substrate Dependent Changes in Fibrinogen and Von Willebrand Factor Studied by Atomic Force Microscopy

1998 ◽  
Vol 4 (S2) ◽  
pp. 924-925
Author(s):  
Roger E. Marchant ◽  
P. Sidney Sit ◽  
Madhusudan Raghavachari ◽  
Christopher A. Siedlecki
Keyword(s):  
Atomic Force Microscopy ◽  
Von Willebrand Factor ◽  
Hydrophobic Surface ◽  
Three Dimensions ◽  
Human Fibrinogen ◽  
Force Microscopy ◽  
Atomic Force ◽  
Aqueous Conditions ◽  
Von Willebrand ◽  
Willebrand Factor

Atomic force microscopy (AFM) provides unique opportunities to study cell-surface and molecular scale interactions in three dimensions under aqueous conditions. Two plasma proteins, von Willebrand Factor (vWf) and fibrinogen, play central roles in the regulation of hemostasis and thrombosis by participating in coagulation and facilitating adhesion and aggregation of activated platelets. vWf and fibrinogen are believed to facilitate platelet adhesion under regions of relatively high and low vascular wall shear stress, respectively. Consequently, elucidating vWf and fibrinogen structure-function relations under shear is of considerable importance in developing a comprehensive understanding of the pathophysiology of thrombogenesis. Previously, we reported on molecular level AFM images of human vWf during shear-induced structural transition and human fibrinogen under aqueous conditions when both proteins were adsorbed on a hydrophobic surface. This presentation will report on the shear dependent interactions of dimeric and multimeric vWf with a hydrophobic surface and the substrate-dependent interactions of fibrinogen.

scholarly journals Interactions of von Willebrand factor on mica studied by atomic force microscopy

1992 ◽  
Vol 148 (1) ◽  
pp. 261-272 ◽  
Author(s):  
Roger E Marchant ◽  
A.Scott Lea ◽  
Joseph D Andrade ◽  
Paula Bockenstedt
Keyword(s):  
Atomic Force Microscopy ◽  
Von Willebrand Factor ◽  
Force Microscopy ◽  
Atomic Force ◽  
Von Willebrand ◽  
Willebrand Factor

Comparison of plasma-derived and recombinant von Willebrand factor by atomic force microscopy

2010 ◽  
Vol 104 (09) ◽  
pp. 523-530 ◽  
Author(s):  
Birgit Seyfried ◽  
Gernot Friedbacher ◽  
Hanspeter Rottensteiner ◽  
Hans Peter Schwarz ◽  
Hartmut Ehrlich ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Shear Stress ◽  
Von Willebrand Factor ◽  
Globular Domain ◽  
Force Microscopy ◽  
Molecular Weights ◽  
Atomic Force ◽  
Similar Range ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryHuman plasma protein von Willebrand factor (VWF) is composed of a series of multimers with molecular weights ranging from 600 to 20,000 kDa or even more. Plasma-derived VWF (pdVWF) and recombinant VWF (rVWF) differ in that the ultra-large molecular weight multimer portion present in rVWF is usually missing in pdVWF due to partial cleavage of VWF by the plasma protease ADAMTS13. Here, tapping mode atomic force microscopy (TM-AFM) was used to visualise the shape and size of rVWF and pdVWF. The morphology of the variants of VWF was comparable, containing both globular and stretched domains. Mean chain lengths of the filaments and diameters of the core globular domains were determined and analysed on a statistical basis. About 72% of the pdVWF molecules and 70% of the rVWF molecules were 100–300 nm long. The portion of very long molecules (>300 nm) was only slightly greater in rVWF than in pdVWF (20% vs. 18%). The diameters of the globular core structures were in the range of 12 to 30 nm for both types of VWF. Inspection of a purified rVWF dimer revealed a similar range for the globular domain (14–32 nm). Finally, we demonstrate a dramatic conformational change for rVWF upon exposure to high shear stress, as has been reported for pdVWF. Our TM-AFM data show that the overall structure of rVWF is similar to that of pdVWF and that rVWF will extend its conformation under shear stress, which is required to exert its function in primary haemostasis.

scholarly journals Force sensing by the vascular protein von Willebrand factor is tuned by a strong intermonomer interaction

2016 ◽  
Vol 113 (5) ◽  
pp. 1208-1213 ◽  
Author(s):  
Jochen P. Müller ◽  
Salomé Mielke ◽  
Achim Löf ◽  
Tobias Obser ◽  
Christof Beer ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Single Molecule ◽  
Effective Length ◽  
Force Sensing ◽  
Force Microscopy ◽  
Atomic Force ◽  
Increased Risk ◽  
Afm Imaging ◽  
Von Willebrand ◽  
Willebrand Factor

The large plasma glycoprotein von Willebrand factor (VWF) senses hydrodynamic forces in the bloodstream and responds to elevated forces with abrupt elongation, thereby increasing its adhesiveness to platelets and collagen. Remarkably, forces on VWF are elevated at sites of vascular injury, where VWF’s hemostatic potential is important to mediate platelet aggregation and to recruit platelets to the subendothelial layer. Adversely, elevated forces in stenosed vessels lead to an increased risk of VWF-mediated thrombosis. To dissect the remarkable force-sensing ability of VWF, we have performed atomic force microscopy (AFM)-based single-molecule force measurements on dimers, the smallest repeating subunits of VWF multimers. We have identified a strong intermonomer interaction that involves the D4 domain and critically depends on the presence of divalent ions, consistent with results from small-angle X-ray scattering (SAXS). Dissociation of this strong interaction occurred at forces above ∼50 pN and provided ∼80 nm of additional length to the elongation of dimers. Corroborated by the static conformation of VWF, visualized by AFM imaging, we estimate that in VWF multimers approximately one-half of the constituent dimers are firmly closed via the strong intermonomer interaction. As firmly closed dimers markedly shorten VWF’s effective length contributing to force sensing, they can be expected to tune VWF’s sensitivity to hydrodynamic flow in the blood and to thereby significantly affect VWF’s function in hemostasis and thrombosis.

scholarly journals Atomic Force Microscopy Study of the Conformational Change in Immobilized Calmodulin

Langmuir ◽  
2011 ◽  
Vol 27 (17) ◽  
pp. 10793-10799 ◽  
Author(s):  
Sanja Trajkovic ◽  
Xiaoning Zhang ◽  
Sylvia Daunert ◽  
Yuguang Cai
Keyword(s):  
Atomic Force Microscopy ◽  
Conformational Change ◽  
Microscopy Study ◽  
Atomic Force Microscopy Study ◽  
Force Microscopy ◽  
Atomic Force
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