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Author Notes:

X. Frank Zhang, Email: xiz310@lehigh.edu

N.A.A., E.R.L., and M.S.W. cloned and generated VWF fragments; N.A.A. performed BLI experiments, produced, and ran experiments with VHH81 and 6G1; W.C. performed single-molecule experiments; N.A.A. and E.R.L. ran platelet aggregometry experiments; A.K.B., E.X., and J.E. crystallized and refined structures; M.C.B. provided critical reagents; X.F.Z. and R.L. designed the research; N.A.A., W.C., X.F.Z., J.E., and R.L. analyzed the results; N.A.A., W.C., J.E., X.F.Z., and R.L. prepared the figures; N.A.A. and R.L. wrote the paper; all authors edited the paper.

The authors would like to thank Diamond Light Source for beamtime (proposal MX19880), and the staff of beamlines I04 for assistance.

The authors declare no competing interests.

Subjects:

Research Funding:

This work was supported in part by NIH research grants (HL082808, HL143794, and HL152348), NIH training grants (GM008602 and GM008367), a studentship grant from the British Heart Foundation (FS/18/70/33893) awarded to J.E./A.K.B., and an infrastructure grant from Hemophilia of Georgia Center for Bleeding & Clotting Disorders of Emory. N.A.A. was supported in part by AHA grant 20PRE34990025 and NIH fellowship HL154656. E.R.L. was supported in part by NIH fellowship HL149357.

Keywords:

  • Science & Technology
  • Multidisciplinary Sciences
  • Science & Technology - Other Topics
  • PLATELET GLYCOPROTEIN-IB
  • TERMINAL FLANKING REGION
  • FACTOR A1 DOMAIN
  • IX-V COMPLEX
  • VONWILLEBRAND-FACTOR
  • FACTOR BINDING
  • MONOCLONAL-ANTIBODY
  • CRYSTAL-STRUCTURE
  • SINGLE-MOLECULE
  • A2 DOMAIN

Activation of von Willebrand factor via mechanical unfolding of its discontinuous autoinhibitory module

Journal Title:

NATURE COMMUNICATIONS

Volume:

Volume 12, Number 1

Publisher:

, Pages 2360-2360

Type of Work:

Article | Final Publisher PDF

Abstract:

Von Willebrand factor (VWF) activates in response to shear flow to initiate hemostasis, while aberrant activation could lead to thrombosis. Above a critical shear force, the A1 domain of VWF becomes activated and captures platelets via the GPIb-IX complex. Here we show that the shear-responsive element controlling VWF activation resides in the discontinuous autoinhibitory module (AIM) flanking A1. Application of tensile force in a single-molecule setting induces cooperative unfolding of the AIM to expose A1. The AIM-unfolding force is lowered by truncating either N- or C-terminal AIM region, type 2B VWD mutations, or binding of a ristocetin-mimicking monoclonal antibody, all of which could activate A1. Furthermore, the AIM is mechanically stabilized by the nanobody that comprises caplacizumab, the only FDA-approved anti-thrombotic drug to-date that targets VWF. Thus, the AIM is a mechano-regulator of VWF activity. Its conformational dynamics may define the extent of VWF autoinhibition and subsequent activation under force.

Copyright information:

© The Author(s) 2021

This is an Open Access work distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/rdf).
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