Related Experiment Video
Updated: Jun 1, 2026
13:08
Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
Allosteric activation of coagulation factor VIIa
Egon Persson1, Ole Hvilsted Olsen
1Haemostasis Biochemistry, Novo Nordisk A/S, Novo Nordisk Park, DK-2760 Maaloev, Denmark. egpe@novonordisk.com
Frontiers in Bioscience (Landmark Edition)
|May 31, 2011
Summary
Coagulation factor VIIa (FVIIa) initiates blood clotting upon binding its cofactor, tissue factor (TF). TF binding localizes clotting to injury sites and activates FVIIa, ensuring safe and effective thrombin generation.
Area of Science:
- Biochemistry
- Hematology
- Molecular Biology
Background:
- Coagulation factor VIIa (FVIIa) circulates at low concentrations, comprising a small fraction of total FVII.
- FVIIa initiates blood clotting upon encountering tissue factor (TF), exposed during vascular injury.
Purpose of the Study:
- To review the structure, function, and TF dependence of FVIIa.
- To elucidate the allosteric mechanism by which TF induces FVIIa activation.
Main Methods:
- Literature review of accumulated knowledge on FVIIa and TF.
- Analysis of structural and functional data to propose an allosteric mechanism.
Main Results:
- TF acts as a crucial safety mechanism by localizing clotting to injury sites.
- TF binding induces the maturation of zymogen-like FVIIa into its active cofactor-bound form.
- A plausible allosteric mechanism for TF-induced FVIIa activation is proposed.
Conclusions:
- TF is essential for the timely and localized initiation of blood coagulation.
- TF binding is critical for converting free FVIIa to its active conformation.
- Understanding this mechanism enhances knowledge of hemostasis and thrombosis.
Related Concept Videos
01:20Extrinsic and Intrinsic Pathways of Hemostasis
Blood clotting or coagulation involves extrinsic and intrinsic pathways, which ultimately merge into the common pathway, forming a fibrin clot.
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which forms a...
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which forms a...
01:08Allosteric Regulation
Allosteric regulation of enzymes occurs when the binding of an effector molecule to a site that is different from the active site causes a change in the enzymatic activity. This alternate site is called an allosteric site, and an enzyme can contain more than one of these sites. Allosteric regulation can either be positive or negative, resulting in an increase or decrease in enzyme activity. Most enzymes that display allosteric regulation are metabolic enzymes involved in the degradation or...
01:08Allosteric Regulation
Allosteric regulation of enzymes occurs when the binding of an effector molecule to a site that is different from the active site causes a change in the enzymatic activity. This alternate site is called an allosteric site, and an enzyme can contain more than one of these sites. Allosteric regulation can either be positive or negative, resulting in an increase or decrease in enzyme activity. Most enzymes that display allosteric regulation are metabolic enzymes involved in the degradation or...
01:30Anticoagulant Drugs: Low-Molecular-Weight Heparins
Hemostasis is a crucial process that prevents excessive blood loss from damaged blood vessels. It involves various mechanisms such as vasoconstriction, platelet adhesion and activation, and fibrin formation. The importance of each mechanism depends on the type of vessel injury. In contrast, thrombosis is the abnormal formation of a blood clot within the blood vessels, leading to potential complications if the clot obstructs blood flow. Thrombosis can be caused by increased coagulability of the...
01:58Cooperative Allosteric Transitions
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
01:58Cooperative Allosteric Transitions
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...