Related Experiment Video

Updated: Jul 18, 2026

Investigating von Willebrand Factor Pathophysiology Using a Flow Chamber Model of von Willebrand Factor-platelet String Formation
08:30

Investigating von Willebrand Factor Pathophysiology Using a Flow Chamber Model of von Willebrand Factor-platelet String Formation

Published on: August 14, 2017

Characterization of a core binding site for ADAMTS-13 in the A2 domain of von Willebrand factor

Jing-Jiang Wu1, Kazuo Fujikawa, Brad A McMullen

  • 1Department of Biochemistry, University of Washington, Seattle, WA 98195, USA.

Proceedings of the National Academy of Sciences of the United States of America
|November 24, 2006
PubMed

Insights

ADAMTS-13 cleaves von Willebrand factor (VWF) to regulate blood clotting. Researchers identified a key peptide sequence that binds to ADAMTS-13, inhibiting its activity and revealing an extended binding site.

Area of Science:

  • Biochemistry
  • Hematology
  • Molecular Biology

Background:

  • ADAMTS-13 is a plasma metalloprotease crucial for primary hemostasis.
  • It specifically cleaves von Willebrand factor (VWF), regulating its polymer distribution.
  • VWF73 peptide was previously identified as the minimal substrate for ADAMTS-13.

Purpose of the Study:

  • To identify the minimal peptide sequence of VWF73 that binds and inhibits ADAMTS-13.
  • To investigate the role of specific amino acid residues in substrate recognition by ADAMTS-13.
  • To characterize the binding interactions between ADAMTS-13 and its substrate.

Main Methods:

  • Enzymatic and chemical cleavage of VWF73 into shorter peptides.
  • Quantitative assay to measure inhibition of VWF73-derived substrate cleavage.
  • Competition studies using purified peptides to determine binding affinity (Ki).
  • Site-directed mutagenesis to assess the role of specific amino acids (Asp1653, Asp1663, Glu1655).

Main Results:

  • A 24-amino acid peptide (Pro-1645-Lys-1668) was identified as the minimal inhibitor of ADAMTS-13.
  • This peptide competitively inhibited ADAMTS-13 with a Ki of 12 microM.
  • The peptide and longer variants inhibited cleavage of multimeric VWF by ADAMTS-13.
  • Mutations Asp1653Ala and Asp1663Ala reduced cleavage rates, while Glu1655Ala enhanced it, suggesting ionic interactions are important.

Conclusions:

  • A complementary extended binding site (exosite) on ADAMTS-13 is suggested by the inhibitory peptide.
  • Ionic interactions within the Pro-1645-Lys-1668 region are critical for ADAMTS-13 substrate recognition.
  • These findings advance the understanding of VWF processing and ADAMTS-13 function in hemostasis.

More Related Videos

In Vitro and In Vivo Model to Study Bacterial Adhesion to the Vessel Wall Under Flow Conditions10:24

In Vitro and In Vivo Model to Study Bacterial Adhesion to the Vessel Wall Under Flow Conditions

Published on: June 11, 2015

Live-cell Imaging of Platelet Degranulation and Secretion Under Flow11:42

Live-cell Imaging of Platelet Degranulation and Secretion Under Flow

Published on: July 10, 2017

Related Concept Videos

Conserved Binding Sites01:49

Conserved Binding Sites

Many proteins’ biological role depends on their interactions with their ligands, small molecules that bind to specific locations on the protein known as ligand-binding sites. Ligand-binding sites are often conserved among homologous proteins as these sites are critical for protein function.
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the...
Conserved Binding Sites01:49

Conserved Binding Sites

Many proteins’ biological role depends on their interactions with their ligands, small molecules that bind to specific locations on the protein known as ligand-binding sites. Ligand-binding sites are often conserved among homologous proteins as these sites are critical for protein function.
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the...
Intracellular Signaling Affects Focal Adhesions01:17

Intracellular Signaling Affects Focal Adhesions

Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active.
Some...
Ligand Binding and Linkage00:49

Ligand Binding and Linkage

Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked.  In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence the...
Tension Response at Adherens Junctions01:26

Tension Response at Adherens Junctions

The adherens junctions that anchor cells together are multi-protein complexes that dynamically adapt to mechanical stimuli such as tensile forces and shear stress. Mechanosensory proteins in these junctions can sense such mechanical stimuli and undergo a shift in their conformation, resulting in an altered function — a process called mechanotransduction.
α-Catenin as a Mechanosensory Protein
The α-catenin of adherens junctions is an allosteric protein with three VH (vinculin homology) domains...
Ligand Binding Sites02:40

Ligand Binding Sites

Proteins are dynamic macromolecules that carry out a wide variety of essential processes; however, the activities of most proteins depend on their interactions with other molecules or ions, known as ligands.
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...