| Identifiers | |
| Symbol | FGA |
| Entrez | 2243 |
| HUGO | 3661 |
| OMIM | 134820 |
| RefSeq | NM_000508 |
| UniProt | P02671 |
| Other data | |
| Locus | Chr. 4 q28 |
Fibrin is a protein involved in the clotting of blood. Fibrinogen alpha chain, also known as FGA, is a human Gene. Fibrinogen alpha chain, also known as FGA, is a human Gene. The Entrez Global Query Cross-Database Search System is a powerful Federated search engine or Web portal that allows users to search many discrete Health sciences The Human Genome Organisation (HUGO is an organization involved in the Human Genome Project, a project about mapping the human genome The Mendelian Inheritance in Man project is a Database that catalogues all the known Diseases with a genetic component, and—when possible—links them The National Center for Biotechnology Information ( NCBI) is part of the United States National Library of Medicine (NLM a branch of the National Institutes Swiss-Prot is a manually curated Biological database of Protein sequences In the fields of Genetics and Evolutionary computation, a locus (plural loci) is a fixed position on a Chromosome such as the position of a Chromosome 4 is one of the 23 pairs of Chromosomes in Humans People normally have two copies of this chromosome Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl It is a fibrillar protein that is polymerised to form a "mesh" that forms a hemostatic plug or clot (in conjunction with platelets) over a wound site. In Polymer chemistry, polymerization is a process of reacting Monomer Molecules together in a Chemical reaction to form three-dimensional networks Hemostasis (or Haemostasis refers to a process whereby bleeding is halted in most animals with a closed Circulatory system. Platelets, or Thrombocytes, are small cytoplasmic bodies derived from cells They circulate in the Blood of Mammals and are involved
Fibrin is made from its zymogen fibrinogen, a soluble plasma glycoprotein that is synthesised by the liver. A zymogen (or proenzyme) is an inactive Enzyme precursor. A zymogen requires a biochemical change (such as a Hydrolysis reaction revealing the Blood plasma is the Liquid component of Blood, in which the Blood cells are suspended Not to be confused with Peptidoglycan. Glycoproteins are proteins that contain Oligosaccharide chains ( Glycans) covalently attached The liver is a vital organ in the human body and is present in Vertebrates and some other animals Processes in the coagulation cascade activate the zymogen prothrombin to the serine protease thrombin, which is responsible for converting fibrinogen into fibrin. Coagulation is a complex process by which Blood forms Clots It is an important part of Hemostasis (the cessation of blood loss from a damaged vessel whereby Thrombin (activated Factor II ') is a Coagulation protein that has many effects in the coagulation cascade. Serine proteases or serine endopeptidases (newer name are Proteases ( Enzymes that cut Peptide bonds in Proteins in which one of Thrombin (activated Factor II ') is a Coagulation protein that has many effects in the coagulation cascade. Fibrin is then cross linked by factor XIII to form a clot. Factor XIII or fibrin stabilizing factor is an Enzyme ( of the blood coagulation system that crosslinks Fibrin. Recent research has shown that fibrin plays a key role in the inflammatory response and development of rheumatoid arthritis.
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Physiology
Fibrinogen (also called factor I) is a 340 kDa glycoprotein synthesised in the liver by hepatocytes and megakaryocytes. The concentration in blood plasma is 1. 5 - 4. 0 g/L (normally measured using the Clauss method) or about 7 µM. In its natural form, fibrinogen can form bridges between platelets, by binding to their GpIIb/IIIa surface membrane proteins; however its major function is as the precursor to fibrin.
Fibrinogen, the principal protein of vertebrate blood clotting, is an hexamer containing two sets of three different chains (α, β, and γ), linked to each other by disulfide bonds. The N-terminal sections of these three chains are evolutionary related and contain the cysteines that participate in the cross-linking of the chains. However, there is no similarity between the C-terminal part of the α chain and that of the β and γ chains. The C-terminal part of the β and γ chains forms a domain of about 270 amino-acid residues. This domain contains four conserved cysteines involved in two disulfide bonds. On the alpha and beta chains, there is a small peptide sequence (called a fibrinopeptide). It is these small peptides that prevent fibrinogen spontaneously forming polymers with itself.
- Fibrinogen [1] beta and gamma chains C-terminal domain signature
Role in disease
Excessive generation of fibrin due to activation of the coagulation cascade leads to thrombosis, while ineffective generation predisposes to hemorrhage. Thrombosis is the formation of a blood Clot ( Thrombus) inside a Blood vessel, obstructing the flow of Blood through the Circulatory Bleeding, technically known as hemorrhaging / haemorrhaging (see American and British spelling differences) is the loss of Blood from
Dysfunction or disease of the liver can lead to a decrease in fibrinogen production or the production of abnormal fibrinogen molecules with reduced activity (dysfibrinogenaemia). Hereditary abnormalities of fibrinogen (the gene is carried on chromosome 4) are of both quantitative and qualitative in nature and include; afibrinogenaemia, hypofibrinogenaemia, dysfibrinogenaemia, and hypodysfibrinogenaemia. Congenital afibrinogenemia is a rare inherited blood disorder in which the Blood does not clot normally due to a lack of or a malfunction involving Fibrinogen, a
Diagnostic use
Fibrinogen levels can be measured in venous blood. In the Circulatory system, a vein is a Blood vessel that carries Blood back toward the Heart (as opposed to Artery, a blood vessel Normal levels are about 150-300 mg/dL. Higher levels are, amongst others, associated with cardiovascular disease (>460 mg/dL). Cardiovascular disease or cardiovascular diseases refers to the class of diseases that involve the Heart or Blood vessels ( arteries and It may be elevated in any form of inflammation, as it is an acute phase protein. Inflammation ( Latin, inflamatio, to set on fire is the complex biological response of vascular tissues to harmful stimuli such as Pathogens Acute-phase proteins are a class of Proteins whose plasma concentrations increase (positive acute phase proteins or decrease (negative acute phase proteins in response to
It is used in veterinary medicine as an inflammatory marker: in horses a level above the normal range of 1. Veterinary medicine the application of medical, diagnostic, and therapeutic principles to companion, domestic, exotic, wildlife 0-4. 0 g/L suggests some degree of systemic inflammatory response.
Low levels of fibrinogen can indicate a systemic activation of the clotting system, with consumption of clotting factors faster than synthesis. This excessive clotting factor consumption condition is known as Disseminated Intravascular Coagulation or "DIC. " DIC can be difficult to diagnose, but a strong clue is low fibrinogen levels in the setting of prolonged clotting times (PT or PTT), in the context of acute critical illness such as sepsis or trauma.
See also
External links
- Defibrinated blood harvested from sheep video
Dictionary
fibrin
-noun
- A white, albuminous, fibrous substance, formed in the coagulation of the blood.
- An elastic, insoluble, whitish protein produced by the action of thrombin on fibrinogen and forming an interlacing fibrous network in the coagulation of blood.
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