Prothrombinase complex
The prothrombinase complex is a building block of plasmatic coagulation (secondary hemostasis ) composed of several factors .
The complex consists of four factors:
- Stuart Prower factor (factor X),
- Proaccelerin (factor V),
- Phospholipids and
- Calcium ions (factor IV)
The task of the prothrombinase complex is to activate factor II (prothrombin) to factor IIa (thrombin) and thus forms a central point in the coagulation cascade. It first assembles on the surface of tissue factor- bearing cells. In the further course of coagulation, it can also be found on the surface of activated platelets .
It should be noted, however, that factor X is activated by the initiation complex of tissue factor (TF / factor III) and factor VII , while factor V is activated by thrombin that has already been activated. This connection, which at first glance seems paradoxical, can be explained by the fact that plasmatic coagulation is not a rigid scheme, but a dynamic equilibrium of reactions.
further reading
- Bernd Pötzsch, Katharina Madlener: Hemostaseology. Basics, diagnostics and therapy Springer, 2010, ISBN 978-3642015434
- PN Walsh, SS Ahmad: Proteases in blood clotting. In: Essays in biochemistry. Volume 38, 2002, pp. 95-111, ISSN 0071-1365 . PMID 12463164 . (Review).
- AJ Gale, S. Yegneswaran et al. a .: Characterization of a factor Xa binding site on factor Va near the Arg-506 activated protein C cleavage site. In: The Journal of biological chemistry. Volume 282, Number 30, July 2007, pp. 21848-21855, ISSN 0021-9258 . doi : 10.1074 / jbc.M702192200 . PMID 17553804 .
- ME Nesheim, JB Taswell, KG Mann: The contribution of bovine Factor V and Factor Va to the activity of prothrombinase. In: The Journal of biological chemistry. Volume 254, Number 21, November 1979, pp. 10952-10962, ISSN 0021-9258 . PMID 500617 .
Individual evidence
- ↑ Bernd Pötzsch, Katharina Madlener: Haemostaseology. Basics, diagnostics and therapy Springer, 2010, p. 241, ISBN 978-3642015434