Related Experiment Video
Updated: Jul 24, 2026

Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
Modulation of fibrin cofactor activity in plasminogen activation
1Department of Biochemistry, Queen's University, Kingston, Ontario, Canada, K7L 3N6. nesheimm@post.queensu.ca
Abstract:
Fibrin is a cofactor for the formation of plasmin from plasminogen as catalyzed by tissue plasminogen activator. Initial cleavages of fibrin by plasmin upregulates the cofactor activity of fibrin by exposing carboxyl terminal lysine residues. This effect is eliminated by a carboxypeptidase B-like enzyme generated from the precursor, thrombin activatable fibrinolysis inhibitor (TAFI) that is generated by thrombin during the formation of fibrin. Thus, TAFI and its activation to TAFIa create a link between the coagulation and fibrinolytic cascade, such that activation of the former suppresses the latter. Complete solubilization of fibrin results in a family of very large fibrin degradation products. These also have very substantial tissue plasminogen activator cofactor activity that is very highly downregulated by TAFIa.
More Related Videos
Related Concept Videos
Intracellular Signaling Affects Focal Adhesions
Some...
Anticoagulant Drugs: Low-Molecular-Weight Heparins
Formation of the Platelet Plug
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...
Coagulation
During the coagulation phase, clotting factors, or procoagulants, play a vital role in initiating and progressing the coagulation cascade. This cascade is a series of reactions...
Extrinsic and Intrinsic Pathways of Hemostasis
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...
Clot Retraction and Fibrinolysis

