Development and Applications of Surface Plasmon Resonance-Based von Willebrand Factor– Collagen Binding Assay

2002 ◽  
Vol 302 (2) ◽  
pp. 252-262 ◽  
Author(s):  
Evgueni Saenko ◽  
Christoph Kannicht ◽  
Klemens Loster ◽  
Andrey Sarafanov ◽  
Alexey Khrenov ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Von Willebrand Factor ◽  
Plasmon Resonance ◽  
Binding Assay ◽  
Collagen Binding ◽  
Von Willebrand ◽  
Willebrand Factor

scholarly journals Novel aptamer to von Willebrand factor A1 domain (TAGX-0004) shows total inhibition of thrombus formation superior to ARC1779 and comparable to caplacizumab

Haematologica ◽  
2019 ◽  
Vol 105 (11) ◽  
pp. 2631-2638 ◽  
Author(s):  
Kazuya Sakai ◽  
Tatsuhiko Someya ◽  
Kaori Harada ◽  
Hideo Yagi ◽  
Taei Matsui ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Von Willebrand Factor ◽  
Plasmon Resonance ◽  
Binding Sites ◽  
Thrombus Formation ◽  
Static Conditions ◽  
A1 Domain ◽  
Von Willebrand ◽  
Willebrand Factor

von Willebrand factor (VWF) is a blood glycoprotein that plays an important role in platelet thrombus formation through interaction between its A1 domain and platelet glycoprotein Ib. ARC1779, an aptamer to the VWF A1 domain, was evaluated in a clinical trial for acquired thrombotic thrombocytopenic purpura (aTTP). Subsequently, caplacizumab, an anti-VWF A1 domain nanobody, was approved for aTTP in Europe and the United States. We recently developed a novel DNA aptamer, TAGX-0004, to the VWF A1 domain; it contains an artificial base and demonstrates high affinity for VWF. To compare the effects of these three agents on VWF A1, their ability to inhibit ristocetin- or botrocetin-induced platelet aggregation under static conditions was analyzed, and the inhibition of thrombus formation under high shear stress was investigated in a microchip flow chamber system. In both assays, TAGX-0004 showed stronger inhibition than ARC1779, and had comparable inhibitory effects to caplacizumab. The binding sites of TAGX-0004 and ARC1779 were analyzed with surface plasmon resonance performed using alanine scanning mutagenesis of the VWF A1 domain. An electrophoretic mobility shift assay showed that R1395 and R1399 in the A1 domain bound to both aptamers. R1287, K1362, and R1392 contributed to ARC1779 binding, and F1366 was essential for TAGX-0004 binding. Surface plasmon resonance analysis of the binding sites of caplacizumab identified five amino acids in the VWF A1 domain (K1362, R1392, R1395, R1399, and K1406). These results suggested that TAGX-0004 possessed better pharmacological properties than caplacizumab in vitro and might be similarly promising for aTTP treatment.

scholarly journals Effect of ABO blood group on the collagen-binding assay for von Willebrand factor

2002 ◽  
Vol 71 (3) ◽  
pp. 229-231 ◽  
Author(s):  
Erin Haley ◽  
Nadiya Babar ◽  
Cory Ritter ◽  
Katharine A. Downes ◽  
Deana Green ◽  
...  
Keyword(s):  
Blood Group ◽  
Von Willebrand Factor ◽  
Binding Assay ◽  
Abo Blood Group ◽  
Collagen Binding ◽  
Von Willebrand ◽  
Willebrand Factor

scholarly journals A novel binding site for ADAMTS13 constitutively exposed on the surface of globular VWF

Blood ◽  
2009 ◽  
Vol 114 (13) ◽  
pp. 2819-2828 ◽  
Author(s):  
Sara Zanardelli ◽  
Alain C. K. Chion ◽  
Evelyn Groot ◽  
Peter J. Lenting ◽  
Thomas A. J. McKinnon ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Binding Site ◽  
Surface Plasmon ◽  
Binding Assay ◽  
Initial Step ◽  
Static Conditions ◽  
Von Willebrand ◽  
A2 Domain ◽  
Willebrand Factor

AbstractADAMTS13 metalloprotease regulates the multimeric size of von Willebrand factor (VWF) by cleaving the Tyr1605-Met1606 bond in the VWF A2 domain. The mechanisms of VWF recognition by ADAMTS13 have yet to be fully resolved. Most studies have focused on the role of exosites within the VWF A2 domain, involved in interaction with the ADAMTS13 spacer domain. In the present study, we expressed different C-terminal domain VWF fragments and evaluated their binding to ADAMTS13 and its truncated mutants, MDTCS and del(TSP5-CUB). Using plate binding assay and surface plasmon resonance, we identified a novel ADAMTS13 binding site (KD ∼ 86 nM) in the region of VWF spanning residues 1874 to 2813, which includes the VWF D4 domain and that interacts with the C-terminal domains of ADAMTS13. We show that the interaction occurs even when VWF is in static conditions, assumed to be globular and where the VWF A2 domain is hidden. We demonstrate that C-terminal VWF fragments, as well as an antibody specifically directed toward the VWF D4 domain, inhibit VWF proteolysis by ADAMTS13 under shear conditions. We propose that this novel VWF C-terminal binding site may participate as the initial step of a multistep interaction ultimately leading to proteolysis of VWF by ADAMTS13.

Clinical Use of a Rapid Collagen Binding Assay for von Willebrand Factor Cleaving Protease in Patients with Thrombotic Thrombocytopenic Purpura

2002 ◽  
Vol 88 (10) ◽  
pp. 598-604 ◽  
Author(s):  
Stephan Moll ◽  
Mark Taylor ◽  
Dennis Krizek ◽  
Gilbert White ◽  
David Aronson ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Predictive Value ◽  
Protease Activity ◽  
Binding Assay ◽  
Clinical Syndrome ◽  
Clinical Samples ◽  
Activity Levels ◽  
Collagen Binding ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryA simple collagen binding assay (CBA) for measuring activity of the von Willebrand factor cleaving protease in clinical samples is described, and results of fifty masked plasmapheresis samples from patients with TTP/HUS and other diseases are presented.There was 97.5% concordance between the CBA and a multimer gel assay. The CBA identified low protease activity in 78% of patients who had a clinical syndrome consistent with TTP/HUS and in 2 of 10 sick controls, giving it a positive predictive value of 0.94. The heterogeneity regarding the presence or absence of vWF protease activity in patients with TTP/HUS was confirmed by finding a low negative predictive value of 0.50 with the CBA. The CBA detected inhibitors of the protease in 26 of 29 patients (90%) with TTP/HUS and low protease activity levels. The CBA is a useful clinical assay for examining von Willebrand factor protease activity and detecting inhibitors against the protease.

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