Related Experiment Video
Updated: Apr 9, 2026
10:55
Assays for Studying the Role of Vitronectin in Bacterial Adhesion and Serum Resistance
Published on: October 16, 2018
8.7K
Vitronectin binds to activated human platelets and plays a role in platelet aggregation
1Division of Rheumatic Diseases and Immunology, New York Medical College, Valhalla 10595.
The Journal of Clinical Investigation
|May 1, 1990
Summary
Vitronectin (Vn) binds to human platelets via the GPIIb/IIIa complex in a calcium-dependent manner. This interaction, crucial for platelet aggregation, involves both plasma and endogenous platelet Vn.
Area of Science:
- Biochemistry
- Cell Biology
- Hematology
Background:
- Vitronectin (Vn) is a glycoprotein found in plasma and extracellular matrix, involved in cell adhesion and complement regulation.
- Vn contains the Arg-Gly-Asp sequence, interacting with integrin receptors like platelet glycoprotein complex IIb/IIIa (GPIIb/IIIa).
Purpose of the Study:
- To investigate the binding characteristics of purified Vn to human platelets.
- To determine the role of Vn in platelet function and aggregation.
Main Methods:
- Studied the binding of purified Vn to resting and stimulated human platelets using purified Vn.
- Utilized calcium dependency, specificity, saturation, inhibition assays with tetrapeptide and antibodies, and immunoblots to analyze Vn binding and expression.
Main Results:
- Vitronectin binds to thrombin-stimulated platelets in a calcium-dependent, specific, and saturable manner (Kd 320 nM, 8,000 sites/platelet).
- Epinephrine and ADP stimulation also induced specific Vn binding (Kd 93 nM and 116 nM, respectively).
- Binding was inhibited by RGD-S peptide and anti-GPIIb/IIIa antibodies; endogenous platelet Vn is thrombin-inducible and its antibodies inhibit aggregation.
Conclusions:
- Vitronectin binds to the GPIIb/IIIa complex on activated human platelets.
- Vitronectin plays a significant role in platelet aggregation and the formation of stable platelet aggregates.
More Related Videos
05:43An In Vitro Assay to Study Platelet Migration Using RGD-Functionalized Avidin-Biotin Tethers
Published on: November 8, 2024
940
05:49Procoagulant Platelet Characterization by Measuring Phosphatidylserine Exposure and Microvesicle Release from Human Purified Platelets
Published on: November 29, 2024
1.3K
Related Concept Videos
01:25Fibronectins Connect Cells with ECM
3.7K
Fibronectin is an adhesive glycoprotein present in the extracellular matrix of embryogenic and adult tissue. These molecules primarily aid in regulating cell motility and attachment. A fibronectin molecule is composed of two identical polypeptide chains attached to each other by a pair of disulfide bonds at the C-terminal.
Both proteoglycans and collagen are attached to fibronectin proteins, which, in turn, are attached to integrin proteins. These integrin proteins interact with transmembrane...
Both proteoglycans and collagen are attached to fibronectin proteins, which, in turn, are attached to integrin proteins. These integrin proteins interact with transmembrane...
3.7K
01:17Intracellular Signaling Affects Focal Adhesions
3.8K
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...
Some...
3.8K
01:20Antiplatelet Drugs: Prostaglandin Synthesis, P2Y12 and Glycoprotein IIb/IIIa Inhibitors
1.5K
Antiplatelet drugs emerge as frontline defenders against the insidious threat of thromboembolic diseases, where abnormal clots obstruct vital blood vessels. These drugs stand as bulwarks, inhibiting platelet aggregation and clot formation, thereby mitigating the risk of life-threatening conditions like myocardial infarction, coronary artery disease, and thrombotic strokes.
Prostaglandin synthesis inhibitors, exemplified by the widely known aspirin, wield their power by irreversibly acetylating...
Prostaglandin synthesis inhibitors, exemplified by the widely known aspirin, wield their power by irreversibly acetylating...
1.5K
01:18Structure and Function of Platelets
5.7K
The cell fragments known as platelets are disc-shaped, with an average diameter of about 3 μm and a thickness of roughly 1 μm. They play a crucial role in the body's vascular clotting system, which also involves plasma proteins, blood cells, and blood vessel tissues.
Platelets are continually replenished, circulating in the bloodstream for 9-12 days before being removed by phagocytes, primarily in the spleen. A microliter of circulating blood contains between 150,000 and 450,000...
Platelets are continually replenished, circulating in the bloodstream for 9-12 days before being removed by phagocytes, primarily in the spleen. A microliter of circulating blood contains between 150,000 and 450,000...
5.7K
01:22Formation of the Platelet Plug
10.8K
The platelet phase, the second stage of hemostasis, commences around 15-20 seconds after an injury. It follows and overlaps with the vascular phase, during which blood vessels constrict to minimize blood loss.
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
10.8K
01:16Clot Retraction and Fibrinolysis
10.3K
After a fibrin clot is formed, the next step is clot retraction, a vital process facilitated by platelet contractile proteins, such as actin and myosin. These proteins pull the fibrin strands closer together and condense the clot. This action reduces the size of the clot, creating a smaller, denser structure that effectively seals off the damaged vessel. Clot retraction consolidates the clot and helps with wound healing by bringing the edges of the damaged blood vessel closer together.
10.3K