Description
In order to stop local bleeding, thrombin, a natural thrombin drug that catalyzes
the transformation of fibrinogen to fibrin, is frequently used. Thrombin is synthesized
from cow plasma, and it is used to stop bleeding from open vessels when it
is not possible to use other methods. It is used to stop light bleeding.
Chemical Properties
Thrombin is a sterile lyophilized product of thrombin extracted from bovine or porcine blood and activated, which is white or off-white lyophilized lump or powder. The dry powder is very stable in 2～80C storage, the dry powder is easily soluble in water, 0.9% sodium chloride solution appears turbid, insoluble in organic solvents. It is inactivated within 8h in aqueous solution at room temperature. Therefore, it must be freshly prepared when it is used, and its vitality will be reduced when it meets heat, acid, alkali and metal.
Uses
Thrombin is used in coagulation research, medical research, protein-structure analysis, and biochemical research. It has been used for the stimulation of the platelets.
Uses
Thrombostat (Parke-Davis).
Uses
Thrombin is a trypsin-like serine protease involved in a multitude of processes in the human body. Thrombin generation is the result of limited proteolysis of the vitamin K-dependent zymogen prothrombin. Thrombin is the last enzyme in the clotting cascade functioning to cleave fibrinogen to fibrin which forms the fibrin gel of a haemostatic plug or a pathologic thrombus
General Description
Thrombin is a sterile protein substanceprepared from prothrombin of bovine origin. It is used as atopical hemostatic because it can clot blood, plasma, or a solutionof fibrinogen without addition of other substances.Thrombin also may initiate clotting when combined withgelatin sponge or fibrin foam.
For external use it is applied topically to the wound, as asolution containing 100 to 2,000 National Institutes ofHealth (NIH) units/mL in sodium chloride irrigation or sterilewater for injection or as a dry powder.
Biochem/physiol Actions
The main function of thrombin is the cleavage of fibrinogen to fibrin, to assist stable clot formation. A wide range of mutations in the prothrombin gene contributes to its deficiency resulting in coagulation disorders like dysprothrombinemia and hypoprothrombinemia. High levels of thrombin elicit neurotoxicity in dopaminergic neurons and contributes to the progression of Parkinson′s disease. Altered thrombin levels modulates the coagulation pathway in multiple sclerosis. Patients with coronary artery disease (CAD) show elevated levels of thrombin. Thrombin accumulation in neurofibrillary tangles of the brain may contribute to the aggregation of tau protein and pathophysiology of Alzheimer disease.
Purification Methods
Thrombin is purified by chromatography on a DEAE-cellulose column, while eluting with 0.1M NaCl, pH 7.0, followed by chromatography on Sephadex G-200. The final preparation is free from plasminogen and plasmin. [Yin & Wessler J Biol Chem 243 112 1968.] Thrombin from bovine blood is also purified by chromatography using p-chlorobenzylamino--aminocaproyl agarose, and gel filtration through Sephadex G-25. [Thompson & Davie Biochim Biophys Acta 250 210 1971.] Thrombin from various species was purified initially by precipitation of impurities with rivanol. [Miller Nature 184 450 1959.] Tissue inhibitor of metalloproteins (TIMP, from human blood plasma), Mr ~30,000. These are purified by an [anti-human amniotic fluid-TIMP]-Sepharose immuno-affinity column and eluted with 50mM glycine/HCl pH 3.0 buffer that is 0.5M in NaCl, and followed by gel filtration [Cawston et al. Biochem J 238 677 1986].
Description
Thrombin was purified from human plasma.
Background
Thrombin enzyme (Activated Factor IIa) is an important clotting promoter that controls the transformation of soluble fibrinogen to insoluble active fibrin strands. Thrombin is a coagulation protein and a serine protease (EC 3.4.21.5) that catalyzes many coagulation-related reactions. Thrombin triggers factor-XI, factor-V, Factor-XIII and factor-VIII. Thrombin endorses platelet activation, using activation of protease-activated receptors on the platelet. As a result of its high proteolytic specificity, thrombin has become an important biochemical protein. The thrombin cleavage site (Leu-Val-Pro-Arg-Gly-Ser) is widely used in linker regions of recombinant fusion protein constructs. After the purification of the fusion protein, thrombin is used to cleave between the Arginine and Glycine residues of the cleavage site, efficiently removing the purification tag from the protein of interest with a high degree of specificity.
