Publication Date:
2010-08-21
Description:
Haemostasis in the arteriolar circulation mediated by von Willebrand factor (VWF) binding to platelets is an example of an adhesive interaction that must withstand strong hydrodynamic forces acting on cells. VWF is a concatenated, multifunctional protein that has binding sites for platelets as well as subendothelial collagen. Binding of the A1 domain in VWF to the glycoprotein Ib alpha subunit (GPIbalpha) on the surface of platelets mediates crosslinking of platelets to one another and the formation of a platelet plug for arterioles. The importance of VWF is illustrated by its mutation in von Willebrand disease, a bleeding diathesis. Here, we describe a novel mechanochemical specialization of the A1-GPIbalpha bond for force-resistance. We have developed a method that enables, for the first time, repeated measurements of the binding and unbinding of a receptor and ligand in a single molecule (ReaLiSM). We demonstrate two states of the receptor-ligand bond, that is, a flex-bond. One state is seen at low force; a second state begins to engage at 10 pN with a approximately 20-fold longer lifetime and greater force resistance. The lifetimes of the two states, how force exponentiates lifetime, and the kinetics of switching between the two states are all measured. For the first time, single-molecule measurements on this system are in agreement with bulk phase measurements. The results have important implications not only for how platelets bound to VWF are able to resist force to plug arterioles, but also how increased flow activates platelet plug formation.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4117310/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4117310/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kim, Jongseong -- Zhang, Cheng-Zhong -- Zhang, Xiaohui -- Springer, Timothy A -- HL-48675/HL/NHLBI NIH HHS/ -- P01 HL048675/HL/NHLBI NIH HHS/ -- England -- Nature. 2010 Aug 19;466(7309):992-5. doi: 10.1038/nature09295.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Immune Disease Institute, Children's Hospital Boston and Department of Pathology, Harvard Medical School, 3 Blackfan Circle, Boston, Massachusetts 02115, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20725043" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Arterioles/cytology/*physiology
;
Blood Coagulation/*physiology
;
Blood Platelets/chemistry/cytology/*metabolism
;
Cell Line
;
Hemorheology
;
Humans
;
Kinetics
;
Ligands
;
Membrane Glycoproteins/chemistry/*metabolism
;
Mice
;
Models, Chemical
;
Models, Molecular
;
Platelet Glycoprotein GPIb-IX Complex
;
Protein Binding
;
Protein Structure, Tertiary
;
Tensile Strength
;
von Willebrand Factor/chemistry/*metabolism
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
Permalink
