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U-Plasminogen Activator
Urokinase, also known as urokinase-type plasminogen activator (uPA), is a serine protease present in humans and other animals. The human urokinase protein was discovered, but not named, by McFarlane and Pilling in 1947. Urokinase was originally isolated from human urine, and it is also present in the blood and in the extracellular matrix of many tissues. The primary physiological substrate of this enzyme is plasminogen, which is an inactive form (zymogen) of the serine protease plasmin. Activation of plasmin triggers a proteolytic cascade that, depending on the physiological environment, participates in thrombolysis or extracellular matrix degradation. This cascade had been involved in vascular diseases and cancer progression. Urokinase is encoded in humans by the ''PLAU'' gene, which stands for "plasminogen activator, urokinase". The same symbol represents the gene in other animal species. Function The ''PLAU'' gene encodes a serine protease () involved in degradation of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serine Protease
Serine proteases (or serine endopeptidases) are enzymes that cleave peptide bonds in proteins. Serine serves as the nucleophilic amino acid at the (enzyme's) active site. They are found ubiquitously in both eukaryotes and prokaryotes. Serine proteases fall into two broad categories based on their structure: chymotrypsin-like (trypsin-like) or subtilisin-like. Classification The MEROPS protease classification system counts 16 protein superfamily, superfamilies (as of 2013) each containing many protein family, families. Each superfamily uses the catalytic triad or dyad in a different protein fold and so represent convergent evolution of the catalytic mechanism. The majority belong to the S1 family of the PA clan (superfamily) of proteases. For protein superfamily, superfamilies, P: superfamily, containing a mixture of nucleophile class families, S: purely serine proteases. superfamily. Within each superfamily, protein family, families are designated by their catalytic nucl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urokinase Receptor
The Urokinase receptor, also known as urokinase plasminogen activator surface receptor (uPAR) or CD87 (Cluster of Differentiation 87), is a protein encoded in humans by the PLAUR gene. It is a multidomain glycoprotein tethered to the cell membrane with a (GPI) anchor. uPAR was originally identified as a saturable binding site for urokinase (also known as uPA) on the cell surface. Structure uPAR consists of three tandem LU domains, which are protein domains of the three-finger protein family. The structure of uPAR has been solved by X-ray crystallography in complex with a peptide antagonist and with its native ligand, urokinase. All three three-finger domains are necessary for high affinity binding of the primary ligand, urokinase. In addition, uPAR also interacts with several other proteins, including vitronectin, the uPAR associated protein ( uPARAP) and the integrin family of membrane proteins. It has been possible to express uPAR recombinantly in CHO-cells and S2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salmon
Salmon (; : salmon) are any of several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the genera ''Salmo'' and ''Oncorhynchus'' of the family (biology), family Salmonidae, native to tributary, tributaries of the North Atlantic (''Salmo'') and North Pacific (''Oncorhynchus'') basins. ''Salmon'' is a colloquial or common name used for fish in this group, but is not a scientific name. Other closely related fish in the same family include trout, Salvelinus, char, Thymallus, grayling, Freshwater whitefish, whitefish, lenok and Hucho, taimen, all coldwater fish of the subarctic and cooler temperate regions with some sporadic endorheic populations in Central Asia. Salmon are typically fish migration, anadromous: they hatch in the shallow gravel stream bed, beds of freshwater headstreams and spend their juvenile fish, juvenile years in rivers, lakes and freshwater wetlands, migrate to the ocean as adults and live like sea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasminogen Activator
Plasmin is an important enzyme () present in blood that degrades many blood plasma proteins, including fibrin clots. The degradation of fibrin is termed fibrinolysis. In humans, the plasmin protein (in the zymogen form of plasminogen) is encoded by the ''PLG'' gene. Function Plasmin is a serine protease that acts to dissolve fibrin blood clots. Apart from fibrinolysis, plasmin proteolyses proteins in various other systems: It activates collagenases, some mediators of the complement system, and weakens the wall of the Graafian follicle, leading to ovulation. Plasmin is also integrally involved in inflammation. It cleaves fibrin, fibronectin, thrombospondin, laminin, and von Willebrand factor. Plasmin, like trypsin, belongs to the family of serine proteases. Plasmin is released as a zymogen called plasminogen (PLG) from the liver into the systemic circulation. Two major glycoforms of plasminogen are present in humans - type I plasminogen contains two glycos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein C Inhibitor
Protein C inhibitor (PCI, SERPINA5) is a serine protease inhibitor ( serpin) that limits the activity of protein C (an anticoagulant). An N-terminal fragment of PCI is a possible serum biomarker for prostate cancer. Protein C inhibitor is activated by heparin against thrombin. Protein C inhibitor (PCI) is serine protease inhibitor of serpin type that is found in most tissues and fluids, including blood plasma, seminal plasma and urine of human. It is a 52kD glycoprotein and belongs to serine protease inhibitor ( Serpin) super family of protein. In the beginning protein C Inhibitor (PCI) was identified as an inhibitor of activated protein C (APC), it is currently clear that this inhibitor has an expansive specificity, inhibiting several blood coagulation enzymes counting thrombin and factor Xa. Isolation In the beginning, protein C inhibitor(PCI) was originally identified in human plasma by Griffin and Marlar and first isolation was performed by Suzuki et al. Protein C inh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fibrinolysis
Fibrinolysis is a process that prevents blood clots from growing and becoming problematic. Primary fibrinolysis is a normal body process, while secondary fibrinolysis is the breakdown of clots due to a medicine, a medical disorder, or some other cause. In fibrinolysis, a fibrin clot, the product of coagulation, is broken down. Its main enzyme plasmin cuts the fibrin mesh at various places, leading to the production of circulating fragments that are cleared by other proteases or by the kidney and liver. Physiology Plasmin is produced in an inactive form, plasminogen, in the liver. Although plasminogen cannot cleave fibrin, it still has an affinity for it, and is incorporated into the clot when it is formed. Tissue plasminogen activator (t-PA) and urokinase are the agents that convert plasminogen to the active plasmin, thus allowing fibrinolysis to occur. t-PA is released into the blood slowly by the damaged endothelium of the blood vessels, such that, after several days (when th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urokinase Receptor
The Urokinase receptor, also known as urokinase plasminogen activator surface receptor (uPAR) or CD87 (Cluster of Differentiation 87), is a protein encoded in humans by the PLAUR gene. It is a multidomain glycoprotein tethered to the cell membrane with a (GPI) anchor. uPAR was originally identified as a saturable binding site for urokinase (also known as uPA) on the cell surface. Structure uPAR consists of three tandem LU domains, which are protein domains of the three-finger protein family. The structure of uPAR has been solved by X-ray crystallography in complex with a peptide antagonist and with its native ligand, urokinase. All three three-finger domains are necessary for high affinity binding of the primary ligand, urokinase. In addition, uPAR also interacts with several other proteins, including vitronectin, the uPAR associated protein ( uPARAP) and the integrin family of membrane proteins. It has been possible to express uPAR recombinantly in CHO-cells and S2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Membrane
The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extracellular space). The cell membrane consists of a lipid bilayer, made up of two layers of phospholipids with cholesterols (a lipid component) interspersed between them, maintaining appropriate membrane fluidity at various temperatures. The membrane also contains membrane proteins, including integral proteins that span the membrane and serve as membrane transporters, and peripheral proteins that loosely attach to the outer (peripheral) side of the cell membrane, acting as enzymes to facilitate interaction with the cell's environment. Glycolipids embedded in the outer lipid layer serve a similar purpose. The cell membrane controls the movement of substances in and out of a cell, being selectively permeable to ions and organic mole ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasminogen Activator Inhibitor-2
Plasminogen activator inhibitor-2 (placental PAI, SerpinB2, PAI-2), a serine protease inhibitor of the serpin superfamily, is a coagulation factor that inactivates tissue plasminogen activator and urokinase. It is present in most cells, especially monocytes/macrophages. PAI-2 exists in two forms, a 60-kDa extracellular glycosylated form and a 43-kDa intracellular form. It is present only at detectable quantities in blood during pregnancy, as it is produced by the placenta, and may explain partially the increased rate of thrombosis during pregnancy. The majority of expressed PAI-2 remains unsecreted due to the presence of an inefficient internal signal peptide. Interactions PAI-2 has been reported to bind a series of intracellular and extracellular proteins. Whether PAI-2's physiological function is inhibition of the extracellular protease urokinase and/or whether PAI-2 has intracellular activities remains controversial. At least one of PAI-2's physiological functions may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasminogen Activator Inhibitor-1
Plasminogen activator inhibitor-1 (PAI-1) also known as endothelial plasminogen activator inhibitor (serpin E1) is a protein that in humans is encoded by the ''SERPINE1'' gene. Elevated PAI-1 is a risk factor for thrombosis and atherosclerosis. PAI-1 is a serine protease inhibitor ( serpin) that functions as the principal inhibitor of tissue-type plasminogen activator (tPA) and urokinase (uPA), the activators of plasminogen and hence fibrinolysis (the physiological breakdown of blood clots). It is a serine protease inhibitor (serpin) protein (SERPINE1). The other PAI, plasminogen activator inhibitor-2 (PAI-2) is secreted by the placenta and only present in significant amounts during pregnancy. In addition, protease nexin acts as an inhibitor of tPA and urokinase. PAI-1, however, is the main inhibitor of the plasminogen activators. Genetics The PAI-1 gene is ''SERPINE1'', located on chromosome 7 (7q21.3-q22). There is a common polymorphism known as 4G/5G in the promoter reg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serpin
Serpins are a superfamily of proteins with similar structures that were first identified for their protease inhibition activity and are found in all kingdoms of life. The acronym serpin was originally coined because the first serpins to be identified act on chymotrypsin-like serine proteases (serine protease inhibitors). They are notable for their unusual mechanism of action, in which they irreversibly inhibit their target protease by undergoing a large conformational change to disrupt the target's active site. This contrasts with the more common competitive mechanism for protease inhibitors that bind to and block access to the protease active site. Protease inhibition by serpins controls an array of biological processes, including coagulation and inflammation, and consequently these proteins are the target of medical research. Their unique conformational change also makes them of interest to the structural biology and protein folding research communities. The conformationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasminogen Activator Inhibitor-1
Plasminogen activator inhibitor-1 (PAI-1) also known as endothelial plasminogen activator inhibitor (serpin E1) is a protein that in humans is encoded by the ''SERPINE1'' gene. Elevated PAI-1 is a risk factor for thrombosis and atherosclerosis. PAI-1 is a serine protease inhibitor ( serpin) that functions as the principal inhibitor of tissue-type plasminogen activator (tPA) and urokinase (uPA), the activators of plasminogen and hence fibrinolysis (the physiological breakdown of blood clots). It is a serine protease inhibitor (serpin) protein (SERPINE1). The other PAI, plasminogen activator inhibitor-2 (PAI-2) is secreted by the placenta and only present in significant amounts during pregnancy. In addition, protease nexin acts as an inhibitor of tPA and urokinase. PAI-1, however, is the main inhibitor of the plasminogen activators. Genetics The PAI-1 gene is ''SERPINE1'', located on chromosome 7 (7q21.3-q22). There is a common polymorphism known as 4G/5G in the promoter reg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
