Dataset Information

Control of VWF A2 domain stability and ADAMTS13 access to the scissile bond of full-length VWF.

ABSTRACT: Rheological shear forces in the blood trigger von Willebrand factor (VWF) unfolding which exposes the Y1605-M1606 scissile bond within the VWF A2 domain for cleavage by ADAMTS13. The VWF A2 domain contains 2 structural features that provide it with stability: a vicinal disulphide bond and a Ca(2+)-binding site (CBS). We investigated how these 2 structural features interplay to determine stability and regulate the exposure of the scissile bond in full-length VWF. We have used differential scanning fluorimetry together with site-directed mutagenesis of residues involved in both the vicinal disulphide bond and the CBS to demonstrate that both of these sites contribute to stability against thermal unfolding of the isolated VWF A2 domain. Moreover, we show that the combination of site mutations can result in increased susceptibility of FL-VWF to proteolysis by ADAMTS13, even in the absence of an agent (such as urea) required to induce unfolding. These studies demonstrate that VWF A2 domain stability provided by its 2 structural elements (vicinal disulphide bond and CBS) is a key protective determinant against FL-VWF cleavage by ADAMTS13. They suggest a 2-step mechanism for VWF A2 domain unfolding.

SUBMITTER: Lynch CJ

PROVIDER: S-EPMC3990914 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Control of VWF A2 domain stability and ADAMTS13 access to the scissile bond of full-length VWF.

Lynch Christopher J CJ Lane David A DA Luken Brenda M BM

Blood 20140220 16

Rheological shear forces in the blood trigger von Willebrand factor (VWF) unfolding which exposes the Y1605-M1606 scissile bond within the VWF A2 domain for cleavage by ADAMTS13. The VWF A2 domain contains 2 structural features that provide it with stability: a vicinal disulphide bond and a Ca(2+)-binding site (CBS). We investigated how these 2 structural features interplay to determine stability and regulate the exposure of the scissile bond in full-length VWF. We have used differential scannin ...[more]

PMID: 24558203

Similar Datasets

Project description:BackgroundConsistent with fulminant endothelial cell activation, elevated plasma von Willebrand factor (VWF) antigen levels have been reported in patients with COVID-19. The multimeric size and function of VWF are normally regulated through A Disintegrin And Metalloprotease with ThrombSpondin Motif type 1 motif, member 13 (ADAMTS-13)--mediated proteolysis.ObjectivesThis study investigated the hypothesis that ADAMTS-13 regulation of VWF multimer distribution may be impaired in severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection contributing to the observed microvascular thrombosis.Patients and methodsPatients with COVID-19 (n = 23) were recruited from the Beaumont Hospital Intensive Care Unit (ICU) in Dublin. Plasma VWF antigen, multimer distribution, ADAMTS-13 activity, and known inhibitors thereof were assessed.ResultsWe observed markedly increased VWF collagen-binding activity in patients with severe COVID-19 compared to controls (median 509.1 versus 94.3 IU/dl). Conversely, plasma ADAMTS-13 activity was significantly reduced (median 68.2 IU/dl). In keeping with an increase in VWF:ADAMTS-13 ratio, abnormalities in VWF multimer distribution were common in patients with COVID-19, with reductions in high molecular weight VWF multimers. Terminal sialylation regulates VWF susceptibility to proteolysis by ADAMTS-13 and other proteases. We observed that both N- and O-linked sialylation were altered in severe COVID-19. Furthermore, plasma levels of the ADAMTS-13 inhibitors interleukin-6, thrombospondin-1, and platelet factor 4 were significantly elevated.ConclusionsThese findings support the hypothesis that SARS-CoV-2 is associated with profound quantitative and qualitative increases in plasma VWF levels, and a multifactorial down-regulation in ADAMTS-13 function. Further studies will be required to determine whether therapeutic interventions to correct ADAMTS-13-VWF multimer dysfunction may be useful in COVID-microvascular thrombosis and angiopathy.

Dataset Information

Control of VWF A2 domain stability and ADAMTS13 access to the scissile bond of full-length VWF.

Publications

Control of VWF A2 domain stability and ADAMTS13 access to the scissile bond of full-length VWF.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets