Thrombin
Encyclopedia
Thrombin is a "trypsin
-like" serine protease
protein that in humans is encoded by the F2 gene
. Prothrombin (coagulation factor II) is proteolytically cleaved to form thrombin in the first step of the coagulation cascade, which ultimately results in the stemming of blood loss. Thrombin in turn acts as a serine protease
that converts soluble fibrinogen
into insoluble strands of fibrin
, as well as catalyzing many other coagulation-related reactions.
and fibrin, Alexander Schmidt
hypothesised the existence of an enzyme that converts fibrinogen into fibrin in 1872.
(Xa). The activity of factor Xa is greatly enhanced by binding to activated Factor V
(Va), termed the prothrombinase complex. Prothrombin is produced in the liver and is post-translationally modified in a vitamin K
-dependent reaction that converts ten glutamic acids on prothrombin to gamma-carboxyglutamic acid (Gla). In the presence of calcium, the Gla residues promote the binding of prothrombin to phospholipid bilayers (see the picture). Deficiency of vitamin K or administration of the anticoagulant warfarin
inhibits the production of gamma-carboxyglutamic acid residues, slowing the activation of the coagulation cascade.
In human adults, the normal blood level of antithrombin
activity has been measured to be around 1.1 units/mL. Newborn levels of thrombin steadily increase after birth to reach normal adult levels, from a level of around 0.5 units/mL 1 day after birth, to a level of around 0.9 units/mL after 6 months of life.
to XIa, VIII
to VIIIa, V
to Va, and fibrinogen
to fibrin
.
Factor XIIIa is a transglutaminase
that catalyzes the formation of covalent bonds between lysine and glutamine residues in fibrin. The covalent bonds increase the stability of the fibrin clot. Thrombin interacts
with thrombomodulin
.
As part of its activity in the coagulation cascade, thrombin also promotes platelet
activation and aggregation via activation of protease-activated receptor
s on the cell membrane of the platelet.
, an inhibitor of the coagulation cascade. The activation of protein C is greatly enhanced following the binding of thrombin to thrombomodulin
, an integral membrane protein expressed by endothelial cells. Activated protein C inactivates factors Va and VIIIa. Binding of activated protein C to protein S leads to a modest increase in its activity. Thrombin is also inactivated by antithrombin
, a serine protease inhibitor
.
The molecular weight of prothrombin is approximately 72,000 Da
. The catalytic domain is released from prothrombin fragment 1.2 to create the active enzyme thrombin, which has a molecular weight of 36,000 Da.
is located on the eleventh chromosome
(11p11-q12).
There are an estimated 30 people in the world that have been diagnosed with the congenital form of Factor II deficiency, which should not be confused with a mutation of prothrombin. The prothrombin gene mutation is called Factor II mutation. Factor II mutation is congenital.
The Factor II mutated gene is not usually accompanied by other factor mutations (i.e., the most common is Factor V Leiden). The gene may be inherited heterozygous (1 pair), or much more rarely, homozygous (2 pairs), and is not related to gender or blood type. Homozygous mutations increase the risk of thrombosis more than heterozygous mutations, but the relative increased risk is not well documented. Other potential risks for thrombosis, such as oral contraceptives may be additive. The previously reported relationship of inflammatory bowel disease (i.e., Crohn's disease or Ulcerative Colitis) and prothrombin mutation or Factor V
Leiden mutation have been contradicted by research.
). Anti-prothrombin antibodies in autoimmune disease
may be a factor in the formation of the lupus anticoagulant
also known as (antiphospholipid syndrome
). Hyperprothrombinemia
can be caused by a mutation at 20210a.
Thrombin, a potent vasoconstrictor and mitogen
, is implicated as a major factor in vasospasm
following subarachnoid hemorrhage
. Blood from a ruptured cerebral aneurysm
clots around a cerebral artery
, releasing thrombin. This can induce an acute and prolonged narrowing of the blood vessel, potentially resulting in cerebral ischemia
and infarction
(stroke
).
Beyond its key role in the dynamic process of thrombus formation, thrombin has a pronounced pro-inflammatory character, which may influence the onset and progression of atherosclerosis. Acting via its specific cell membrane receptors (protease activated receptors: PAR-1, PAR-3 and PAR-4), which are abundantly expressed in all arterial vessel wall constituents, thrombin has the potential to exert pro-atherogenic actions such as inflammation, leukocyte recruitment into the atherosclerotic plaque, enhanced oxidative stress, migration and proliferation of vascular smooth muscle cells, apoptosis and angiogenesis.
and fresh frozen plasma
are prothrombin-rich coagulation factor preparations that can be used to correct deficiencies (usually due to medication) of prothrombin. Indications include intractable bleeding due to warfarin
.
Manipulation of prothrombin is central to the mode of action of most anticoagulant
s. Warfarin
and related drugs inhibit vitamin K
-dependent carboxylation of several coagulation factors, including prothrombin. Heparin
increases the affinity of antithrombin to thrombin (as well as factor X
a). The direct thrombin inhibitor
s, a newer class of medication, directly inhibit thrombin by binding to its active site.
Recombinant thrombin is available as a powder for reconstitution into aqueous solution
. It can be applied topical
ly during surgery, as an aid to hemostasis
. It can be useful for controlling minor bleeding from capillaries and small venules, but ineffective and not indicated for massive or brisk arterial bleeding. It is marketed by ZymoGenetics
in the US under the trade name Recothrom.
s or bovine blood. According to the manufacturer it can be used to produce new kinds of mixed meats (for example combining beef and fish seamlessly). The manufacturer also states that it can be used to combine scrap meat into whole steaks that can then be sold to a higher price, thus cutting down on production costs.
General secretary Jan Bertoft of Sveriges Konsumenter (The Consumer Coalition of Sweden) has stated that "there is danger of misleading the consumers since there is no way to tell this reconstituted meat from real meat"
Trypsin
Trypsin is a serine protease found in the digestive system of many vertebrates, where it hydrolyses proteins. Trypsin is produced in the pancreas as the inactive proenzyme trypsinogen. Trypsin cleaves peptide chains mainly at the carboxyl side of the amino acids lysine or arginine, except when...
-like" serine protease
Serine protease
Serine proteases are enzymes that cleave peptide bonds in proteins, in which serine serves as the nucleophilic amino acid at the active site.They are found ubiquitously in both eukaryotes and prokaryotes...
protein that in humans is encoded by the F2 gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
. Prothrombin (coagulation factor II) is proteolytically cleaved to form thrombin in the first step of the coagulation cascade, which ultimately results in the stemming of blood loss. Thrombin in turn acts as a serine protease
Serine protease
Serine proteases are enzymes that cleave peptide bonds in proteins, in which serine serves as the nucleophilic amino acid at the active site.They are found ubiquitously in both eukaryotes and prokaryotes...
that converts soluble fibrinogen
Fibrinogen
Fibrinogen is a soluble plasma glycoprotein, synthesised by the liver, that is converted by thrombin into fibrin during blood coagulation. This is achieved through processes in the coagulation cascade that activate the zymogen prothrombin to the serine protease thrombin, which is responsible for...
into insoluble strands of fibrin
Fibrin
Fibrin is a fibrous, non-globular protein involved in the clotting of blood. It is a fibrillar protein that is polymerised to form a "mesh" that forms a hemostatic plug or clot over a wound site....
, as well as catalyzing many other coagulation-related reactions.
History
After the description of fibrinogenFibrinogen
Fibrinogen is a soluble plasma glycoprotein, synthesised by the liver, that is converted by thrombin into fibrin during blood coagulation. This is achieved through processes in the coagulation cascade that activate the zymogen prothrombin to the serine protease thrombin, which is responsible for...
and fibrin, Alexander Schmidt
Alexander Schmidt (physiologist)
Alexander Schmidt was a Livonian physiologist. He was born on the Island of Mohn, which today is called Muhu, Estonia. In 1858, he received his medical doctorate from the University of Dorpat, and later was an assistant to Felix Hoppe-Seyler in Berlin, and Carl Ludwig in Leipzig...
hypothesised the existence of an enzyme that converts fibrinogen into fibrin in 1872.
Synthesis
Thrombin is produced by the enzymatic cleavage of two sites on prothrombin by activated Factor XFactor X
Factor X, also known by the eponym Stuart-Prower factor or as prothrombinase, is an enzyme of the coagulation cascade. It is a serine endopeptidase .-Physiology:...
(Xa). The activity of factor Xa is greatly enhanced by binding to activated Factor V
Factor V
Factor V is a protein of the coagulation system, rarely referred to as proaccelerin or labile factor. In contrast to most other coagulation factors, it is not enzymatically active but functions as a cofactor...
(Va), termed the prothrombinase complex. Prothrombin is produced in the liver and is post-translationally modified in a vitamin K
Vitamin K
Vitamin K is a group of structurally similar, fat soluble vitamins that are needed for the posttranslational modification of certain proteins required for blood coagulation and in metabolic pathways in bone and other tissue. They are 2-methyl-1,4-naphthoquinone derivatives...
-dependent reaction that converts ten glutamic acids on prothrombin to gamma-carboxyglutamic acid (Gla). In the presence of calcium, the Gla residues promote the binding of prothrombin to phospholipid bilayers (see the picture). Deficiency of vitamin K or administration of the anticoagulant warfarin
Warfarin
Warfarin is an anticoagulant. It is most likely to be the drug popularly referred to as a "blood thinner," yet this is a misnomer, since it does not affect the thickness or viscosity of blood...
inhibits the production of gamma-carboxyglutamic acid residues, slowing the activation of the coagulation cascade.
In human adults, the normal blood level of antithrombin
Antithrombin
Antithrombin is a small protein molecule that inactivates several enzymes of the coagulation system. Antithrombin is a glycoprotein produced by the liver and consists of 432 amino acids. It contains three disulfide bonds and a total of four possible glycosylation sites...
activity has been measured to be around 1.1 units/mL. Newborn levels of thrombin steadily increase after birth to reach normal adult levels, from a level of around 0.5 units/mL 1 day after birth, to a level of around 0.9 units/mL after 6 months of life.
Mechanism of action
In the blood coagulation pathway, thrombin acts to convert factor XIFactor XI
Factor XI or plasma thromboplastin antecedent is the zymogen form of factor XIa, one of the enzymes of the coagulation cascade. Like many other coagulation factors, it is a serine protease. In humans, Factor XI is encoded by the F11 gene....
to XIa, VIII
Factor VIII
Factor VIII is an essential blood clotting factor also known as anti-hemophilic factor . In humans, Factor VIII is encoded by the F8 gene...
to VIIIa, V
Factor V
Factor V is a protein of the coagulation system, rarely referred to as proaccelerin or labile factor. In contrast to most other coagulation factors, it is not enzymatically active but functions as a cofactor...
to Va, and fibrinogen
Fibrinogen
Fibrinogen is a soluble plasma glycoprotein, synthesised by the liver, that is converted by thrombin into fibrin during blood coagulation. This is achieved through processes in the coagulation cascade that activate the zymogen prothrombin to the serine protease thrombin, which is responsible for...
to fibrin
Fibrin
Fibrin is a fibrous, non-globular protein involved in the clotting of blood. It is a fibrillar protein that is polymerised to form a "mesh" that forms a hemostatic plug or clot over a wound site....
.
Factor XIIIa is a transglutaminase
Transglutaminase
Transglutaminases are a family of enzymes that catalyze the formation of a covalent bond between a free amine group and the gamma-carboxamid group of protein- or peptide-bound glutamine. Bonds formed by transglutaminase exhibit high resistance to proteolytic degradation.Transglutaminases were...
that catalyzes the formation of covalent bonds between lysine and glutamine residues in fibrin. The covalent bonds increase the stability of the fibrin clot. Thrombin interacts
Protein-protein interaction
Protein–protein interactions occur when two or more proteins bind together, often to carry out their biological function. Many of the most important molecular processes in the cell such as DNA replication are carried out by large molecular machines that are built from a large number of protein...
with thrombomodulin
Thrombomodulin
Thrombomodulin, CD141 or BDCA-3 is an integral membrane protein expressed on the surface of endothelial cells. In humans, thrombomodulin is encoded by the THBD gene...
.
As part of its activity in the coagulation cascade, thrombin also promotes platelet
Platelet
Platelets, or thrombocytes , are small,irregularly shaped clear cell fragments , 2–3 µm in diameter, which are derived from fragmentation of precursor megakaryocytes. The average lifespan of a platelet is normally just 5 to 9 days...
activation and aggregation via activation of protease-activated receptor
Protease-activated receptor
Protease-activated receptors are a subfamily of related G protein-coupled receptors that are activated by cleavage of part of their extracellular domain. They are highly expressed in platelets, but also on endothelial cells, myocytes and neurons....
s on the cell membrane of the platelet.
Negative feedback
Thrombin bound to thrombomodulin activates protein CProtein C
Protein C, also known as autoprothrombin IIA and blood coagulation factor XIV, is a zymogenic protein, the activated form of which plays an important role in regulating blood clotting, inflammation, cell death and maintaining the permeability of blood vessel walls in humans and other animals...
, an inhibitor of the coagulation cascade. The activation of protein C is greatly enhanced following the binding of thrombin to thrombomodulin
Thrombomodulin
Thrombomodulin, CD141 or BDCA-3 is an integral membrane protein expressed on the surface of endothelial cells. In humans, thrombomodulin is encoded by the THBD gene...
, an integral membrane protein expressed by endothelial cells. Activated protein C inactivates factors Va and VIIIa. Binding of activated protein C to protein S leads to a modest increase in its activity. Thrombin is also inactivated by antithrombin
Antithrombin
Antithrombin is a small protein molecule that inactivates several enzymes of the coagulation system. Antithrombin is a glycoprotein produced by the liver and consists of 432 amino acids. It contains three disulfide bonds and a total of four possible glycosylation sites...
, a serine protease inhibitor
Serpin
Serpins are a group of proteins with similar structures that were first identified as a set of proteins able to inhibit proteases. The acronym serpin was originally coined because many serpins inhibit chymotrypsin-like serine proteases .The first members of the serpin superfamily to be extensively...
.
Protein
Atomic mass unit
The unified atomic mass unit or dalton is a unit that is used for indicating mass on an atomic or molecular scale. It is defined as one twelfth of the rest mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state, and has a value of...
. The catalytic domain is released from prothrombin fragment 1.2 to create the active enzyme thrombin, which has a molecular weight of 36,000 Da.
Gene
The Thrombin (prothrombin) geneGene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
is located on the eleventh chromosome
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
(11p11-q12).
There are an estimated 30 people in the world that have been diagnosed with the congenital form of Factor II deficiency, which should not be confused with a mutation of prothrombin. The prothrombin gene mutation is called Factor II mutation. Factor II mutation is congenital.
The Factor II mutated gene is not usually accompanied by other factor mutations (i.e., the most common is Factor V Leiden). The gene may be inherited heterozygous (1 pair), or much more rarely, homozygous (2 pairs), and is not related to gender or blood type. Homozygous mutations increase the risk of thrombosis more than heterozygous mutations, but the relative increased risk is not well documented. Other potential risks for thrombosis, such as oral contraceptives may be additive. The previously reported relationship of inflammatory bowel disease (i.e., Crohn's disease or Ulcerative Colitis) and prothrombin mutation or Factor V
Factor V
Factor V is a protein of the coagulation system, rarely referred to as proaccelerin or labile factor. In contrast to most other coagulation factors, it is not enzymatically active but functions as a cofactor...
Leiden mutation have been contradicted by research.
Role in disease
Activation of prothrombin is crucial in physiological and pathological coagulation. Various rare diseases involving prothrombin have been described (e.g., hypoprothrombinemiaHypoprothrombinemia
Hypoprothrombinemia is a blood disorder in which a deficiency of prothrombin results in impaired blood clotting, leading to an increased physiological risk for bleeding, especially in the gastrointestinal system, cranial vault, and superficial integumentary system.-Causes:Hypoprothrombinemia can...
). Anti-prothrombin antibodies in autoimmune disease
Autoimmune disease
Autoimmune diseases arise from an overactive immune response of the body against substances and tissues normally present in the body. In other words, the body actually attacks its own cells. The immune system mistakes some part of the body as a pathogen and attacks it. This may be restricted to...
may be a factor in the formation of the lupus anticoagulant
Lupus anticoagulant
Lupus anticoagulant is an immunoglobulin that binds to phospholipids and proteins associated with the cell membrane. It is important to note that this disease name is actually a misnomer...
also known as (antiphospholipid syndrome
Antiphospholipid syndrome
Antiphospholipid syndrome or antiphospholipid antibody syndrome , often also Hughes syndrome, is an autoimmune, hypercoagulable state caused by antibodies against cell-membrane phospholipids that provokes blood clots in both arteries and veins as well as pregnancy-related complications such as...
). Hyperprothrombinemia
Hyperprothrombinemia
Hyperprothrombinemia is a disorder of prothrombin which leads to hypercoagulation.Substitution of adenine for guanine at position 20210 of the prothrombin gene, known as the prothrombin 20210a mutation, prothrombin 20210 mutation and, less precise, just factor II mutation, leads to...
can be caused by a mutation at 20210a.
Thrombin, a potent vasoconstrictor and mitogen
Mitogen
A mitogen is a chemical substance that encourages a cell to commence cell division, triggering mitosis. A mitogen is usually some form of a protein.Mitogenesis is the induction of mitosis, typically via a mitogen....
, is implicated as a major factor in vasospasm
Vasospasm
Vasospasm refers to a condition in which blood vessels spasm, leading to vasoconstriction. This can lead to tissue ischemia and death . Cerebral vasospasm may arise in the context of subarachnoid hemorrhage. Symptomatic vasospasm or delayed cerebral ischemia is a major contributor to...
following subarachnoid hemorrhage
Subarachnoid hemorrhage
A subarachnoid hemorrhage , or subarachnoid haemorrhage in British English, is bleeding into the subarachnoid space—the area between the arachnoid membrane and the pia mater surrounding the brain...
. Blood from a ruptured cerebral aneurysm
Cerebral aneurysm
A cerebral or brain aneurysm is a cerebrovascular disorder in which weakness in the wall of a cerebral artery or vein causes a localized dilation or ballooning of the blood vessel.- Signs and symptoms :...
clots around a cerebral artery
Artery
Arteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....
, releasing thrombin. This can induce an acute and prolonged narrowing of the blood vessel, potentially resulting in cerebral ischemia
Cerebral ischemia
Brain ischemia, also known as cerebral ischemia, is a condition in which there is insufficient blood flow to the brain to meet metabolic demand. This leads to poor oxygen supply or cerebral hypoxia and thus to the death of brain tissue or cerebral infarction / ischemic stroke...
and infarction
Infarction
In medicine, infarction refers to tissue death that is caused by a local lack of oxygen due to obstruction of the tissue's blood supply. The resulting lesion is referred to as an infarct.-Causes:...
(stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
).
Beyond its key role in the dynamic process of thrombus formation, thrombin has a pronounced pro-inflammatory character, which may influence the onset and progression of atherosclerosis. Acting via its specific cell membrane receptors (protease activated receptors: PAR-1, PAR-3 and PAR-4), which are abundantly expressed in all arterial vessel wall constituents, thrombin has the potential to exert pro-atherogenic actions such as inflammation, leukocyte recruitment into the atherosclerotic plaque, enhanced oxidative stress, migration and proliferation of vascular smooth muscle cells, apoptosis and angiogenesis.
Research tool
Due to its high proteolytic specificity, thrombin is a valuable biochemical tool. The thrombin cleavage site (Leu-Val-Pro-Arg-Gly-Ser) is commonly included in linker regions of recombinant fusion protein constructs. Following purification of the fusion protein, thrombin can be used to selectively cleave between the Arginine and Glycine residues of the cleavage site, effectively removing the purification tag from the protein of interest with a high degree of specificity.Medicine and surgery
Prothrombin complex concentrateProthrombin complex concentrate
Prothrombin Complex Concentrate is a combination of blood clotting factors II, VII, IX and X, as well as protein C and S. It reverses the effect of warfarin and is used in cases of significant bleeding in patients with a coagulopathy...
and fresh frozen plasma
Fresh frozen plasma
The term fresh frozen plasma refers to the liquid portion of human blood that has been frozen and preserved after a blood donation and will be used for blood transfusion...
are prothrombin-rich coagulation factor preparations that can be used to correct deficiencies (usually due to medication) of prothrombin. Indications include intractable bleeding due to warfarin
Warfarin
Warfarin is an anticoagulant. It is most likely to be the drug popularly referred to as a "blood thinner," yet this is a misnomer, since it does not affect the thickness or viscosity of blood...
.
Manipulation of prothrombin is central to the mode of action of most anticoagulant
Anticoagulant
An anticoagulant is a substance that prevents coagulation of blood. A group of pharmaceuticals called anticoagulants can be used in vivo as a medication for thrombotic disorders. Some anticoagulants are used in medical equipment, such as test tubes, blood transfusion bags, and renal dialysis...
s. Warfarin
Warfarin
Warfarin is an anticoagulant. It is most likely to be the drug popularly referred to as a "blood thinner," yet this is a misnomer, since it does not affect the thickness or viscosity of blood...
and related drugs inhibit vitamin K
Vitamin K
Vitamin K is a group of structurally similar, fat soluble vitamins that are needed for the posttranslational modification of certain proteins required for blood coagulation and in metabolic pathways in bone and other tissue. They are 2-methyl-1,4-naphthoquinone derivatives...
-dependent carboxylation of several coagulation factors, including prothrombin. Heparin
Heparin
Heparin , also known as unfractionated heparin, a highly sulfated glycosaminoglycan, is widely used as an injectable anticoagulant, and has the highest negative charge density of any known biological molecule...
increases the affinity of antithrombin to thrombin (as well as factor X
Factor X
Factor X, also known by the eponym Stuart-Prower factor or as prothrombinase, is an enzyme of the coagulation cascade. It is a serine endopeptidase .-Physiology:...
a). The direct thrombin inhibitor
Direct thrombin inhibitor
Direct thrombin inhibitors are a class of medication that act as anticoagulants by directly inhibiting the enzyme thrombin. Some are in clinical use, while others are undergoing clinical development...
s, a newer class of medication, directly inhibit thrombin by binding to its active site.
Recombinant thrombin is available as a powder for reconstitution into aqueous solution
Aqueous solution
An aqueous solution is a solution in which the solvent is water. It is usually shown in chemical equations by appending aq to the relevant formula, such as NaCl. The word aqueous means pertaining to, related to, similar to, or dissolved in water...
. It can be applied topical
Topical
In medicine, a topical medication is applied to body surfaces such as the skin or mucous membranes such as the vagina, anus, throat, eyes and ears.Many topical medications are epicutaneous, meaning that they are applied directly to the skin...
ly during surgery, as an aid to hemostasis
Hemostasis
Hemostasis or haemostasis is a process which causes bleeding to stop, meaning to keep blood within a damaged blood vessel . Most of the time this includes blood changing from a liquid to a solid state. Intact blood vessels are central to moderating blood's tendency to clot...
. It can be useful for controlling minor bleeding from capillaries and small venules, but ineffective and not indicated for massive or brisk arterial bleeding. It is marketed by ZymoGenetics
ZymoGenetics
ZymoGenetics is a biotechnology/pharmaceutical company based in Seattle, Washington, involved in the development of therapeutic proteins.The company was founded in 1981 by Professors Earl W. Davie and Benjamin D. Hall of the University of Washington and 1993 Nobel Laureate in Chemistry Michael...
in the US under the trade name Recothrom.
Food production
Thrombin is sold under the brand name Fibrimex for use as a binding agent for meat. The thrombin in Fibrimex derives from pigPig
A pig is any of the animals in the genus Sus, within the Suidae family of even-toed ungulates. Pigs include the domestic pig, its ancestor the wild boar, and several other wild relatives...
s or bovine blood. According to the manufacturer it can be used to produce new kinds of mixed meats (for example combining beef and fish seamlessly). The manufacturer also states that it can be used to combine scrap meat into whole steaks that can then be sold to a higher price, thus cutting down on production costs.
General secretary Jan Bertoft of Sveriges Konsumenter (The Consumer Coalition of Sweden) has stated that "there is danger of misleading the consumers since there is no way to tell this reconstituted meat from real meat"
Further reading
- Degen S: Prothrombin. In: High K, Roberts H, eds. Molecular Basis of Thrombosis and Hemostasis. New York, NY: Marcel Dekker; 1995:75.
External links
- The MEROPSMeropsMerops may refer to:* Merops , a genus of bee-eaters.* MEROPS, an on-line database for peptidases.It may also refer to several figures from Greek mythology:* King of Ethiopia, husband of Clymene, who lay with Helios and bore Phaethon...
online database for peptidases and their inhibitors: S01.217 - GeneReviews/NCBI/NIH/UW entry on Prothrombin Thrombophilia
- http://www.youtube.com/watch?v=H_lVLYgls04 Anti-coagulation & proteases by The Proteolysis MapThe Proteolysis MapThe Proteolysis MAP is an integrated web resource focused on proteases.-Rationale:PMAP is to aid the protease researchers in reasoning about proteolytic networks and metabolic pathways.-History and funding:...
-animation - http://www.proteolysis.org/proteases/m_summarypg/pmap.17563 PMAP: The Proteolysis MapThe Proteolysis MapThe Proteolysis MAP is an integrated web resource focused on proteases.-Rationale:PMAP is to aid the protease researchers in reasoning about proteolytic networks and metabolic pathways.-History and funding:...
/Thrombin