|
Disintegrins
Disintegrins are a family of small proteins (45–84 amino acids in length) from viper venoms that function as potent inhibitors of both platelet aggregation and integrin-dependent cell adhesion. Operation Disintegrins work by countering the blood clotting steps, inhibiting the clumping of platelets. They interact with the beta-1 and -3 families of integrins receptors. Integrins are cell receptors involved in cell–cell and cell–extracellular matrix interactions, serving as the final common pathway leading to aggregation via formation of platelet–platelet bridges, which are essential in thrombosis and haemostasis. Disintegrins contain an RGD (Arg-Gly-Asp) or KGD (Lys-Gly-Asp) sequence motif that binds specifically to integrin IIb-IIIa receptors on the platelet surface, thereby blocking the binding of fibrinogen to the receptor–glycoprotein complex of activated platelets. Disintegrins act as receptor antagonists, inhibiting aggregation induced by ADP, thrombin, platelet- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echis Carinatus
''Echis carinatus'', known as the Sindh saw-scaled viper, saw-scaled viper,Mallow D, Ludwig D, Nilson G (2003). ''True Vipers: Natural History and Toxinology of Old World Vipers''. Malabar, Florida: Krieger Publishing Company. 359 pp. . Indian saw-scaled viper, little Indian viper, a Munich Antivenom Index . Accessed 13 September 2006. and by other #Common names, common names, is a Viperinae, viper species found in parts of the Middle East and Central Asia, and especially the Indian subcontinent. It is the smallest member of the "Big Four (Indian snakes), big four" Indian snakes that are responsible for causing the most snakebite cases and deaths, due to various factors including their frequent occurrence in highly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenosine Diphosphate
Adenosine diphosphate (ADP), also known as adenosine pyrophosphate (APP), is an important organic compound in metabolism and is essential to the flow of energy in living cells. ADP consists of three important structural components: a sugar backbone attached to adenine and two phosphate groups bonded to the 5 carbon atom of ribose. The diphosphate group of ADP is attached to the 5’ carbon of the sugar backbone, while the adenine attaches to the 1’ carbon. ADP can be interconverted to adenosine triphosphate (ATP) and adenosine monophosphate (AMP). ATP contains one more phosphate group than ADP, while AMP contains one fewer phosphate group. Energy transfer used by all living things is a result of dephosphorylation of ATP by enzymes known as ATPases. The cleavage of a phosphate group from ATP results in the coupling of energy to metabolic reactions and a by-product of ADP. ATP is continually reformed from lower-energy species ADP and AMP. The biosynthesis of ATP is achieved th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ADAM2
Disintegrin and metalloproteinase domain-containing protein 2 or Beta-fertilin is an enzyme that in humans is encoded by the ''ADAM2'' gene. Function This gene encodes a member of the ADAM (a disintegrin and metalloprotease domain) family. Members of this family are membrane-anchored proteins structurally related to snake venom disintegrins, and have been implicated in a variety of biological processes involving cell–cell and cell–matrix interactions, including fertilization, muscle development, and neurogenesis. This member is a subunit of an integral sperm membrane heterodimer glycoprotein called fertilin, which plays an important role in sperm-egg interactions. The other subunit is ADAM1 or alpha-fertilin. References Further reading * * * * * * * External links * The MEROPS MEROPS is an online database for peptidases (also known as proteases, proteinases and proteolytic enzymes) and their inhibitors. The classification scheme for peptidases was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Von Willebrand Factor
Von Willebrand factor (VWF) () is a blood glycoprotein that promotes primary hemostasis, specifically, platelet adhesion. It is deficient and/or defective in von Willebrand disease and is involved in many other diseases, including thrombotic thrombocytopenic purpura, Heyde's syndrome, and possibly hemolytic–uremic syndrome. Increased plasma levels in many cardiovascular, neoplastic, metabolic (e.g. diabetes), and connective tissue diseases are presumed to arise from adverse changes to the endothelium, and may predict an increased risk of thrombosis. Biochemistry Synthesis VWF is a large multimeric glycoprotein present in blood plasma and produced constitutively as ultra-large VWF in endothelium (in the Weibel–Palade bodies) and megakaryocytes (α-granules of platelets). Structure VWF is synthesized as a prepropeptide comprising 2813 amino acids in endothelial cells and megakaryocytes. The prepropeptide includes a 22-amino acid signal peptide (SP), a 741-amino acid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ADAMTS13
ADAMTS13 (''a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13'')—also known as ''von Willebrand factor-cleaving protease'' (VWFCP)—is a zinc-containing metalloprotease enzyme that cleaves von Willebrand factor (vWf), a large protein involved in blood clotting. It is secreted into the blood and degrades large vWf multimers, decreasing their activity, hence ''ADAMTS13'' acts to reduce thrombus formation. Genetics The ''ADAMTS13'' gene maps to the ninth chromosome (9q34). Discovery Since 1982 it had been known that thrombotic thrombocytopenic purpura (TTP), one of the microangiopathic hemolytic anemias (see below), was characterized in its familial form by the presence in plasma of unusually large von Willebrand factor multimers (ULVWF). In 1994, vWF was shown to be cleaved between a tyrosine at position 1605 and a methionine at 1606 by a plasma metalloprotease enzyme when it was exposed to high levels of shear stress. In 1996, two research grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ADAMTS
ADAMTS (short for a disintegrin and metalloproteinase with thrombospondin motifs) is a family of multidomain extracellular protease enzymes. 19 members of this family have been identified in humans, the first of which, ADAMTS1, was described in 1997. Known functions of the ADAMTS proteases include processing of procollagens and von Willebrand factor as well as cleavage of aggrecan, versican, brevican and neurocan, making them key remodeling enzymes of the extracellular matrix. They have been demonstrated to have important roles in connective tissue organization, coagulation, inflammation, arthritis, angiogenesis and cell migration. Homologous subfamily of ADAMTSL (ADAMTS-like) proteins, which lack enzymatic activity, has also been described. Most cases of thrombotic thrombocytopenic purpura arise from autoantibody-mediated inhibition of ADAMTS13. Like A disintegrin and metalloproteinase, ADAMs, the name of the ADAMTS family refers to its disintegrin and metalloproteinase activity, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ADAM Protein
ADAMs (short for a disintegrin and metalloproteinase) are a family of single-pass transmembrane and secreted metalloendopeptidases. All ADAMs are characterized by a particular domain organization featuring a pro-domain, a metalloprotease, a disintegrin, a cysteine-rich, an epidermal-growth factor like and a transmembrane domain, as well as a C-terminal cytoplasmic tail. Nonetheless, not all human ADAMs have a functional protease domain, which indicates that their biological function mainly depends on protein–protein interactions. Those ADAMs which are active proteases are classified as sheddases because they cut off or shed extracellular portions of transmembrane proteins. For example, ADAM10 can cut off part of the HER2 receptor, thereby activating it. ADAM genes are found in animals, choanoflagellates, fungi and some groups of green algae. Most green algae and all land plants The embryophytes () are a clade of plants, also known as Embryophyta (Plantae ''sensu strictis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atrolysin E
Atrolysin E (, ''Crotalus atrox metalloendopeptidase e'', ''hemorrhagic toxin e'') is an enzyme. This enzyme catalyses the following chemical reaction : Cleavage of Asn3-Gln, Ser9-His and Ala14-Leu bonds in insulin B chain and Tyr14-Gln and Thr8-Ser in A chain. Cleaves type IV collagen at Ala73-Gln in alpha1(IV) and at Gly7-Leu in alpha2(IV) This endopeptidase is present in the venom of the western diamondback rattlesnake The western diamondback rattlesnake or Texas diamond-backWright AH, Wright AA. (1957). ''Handbook of Snakes''. Comstock Publishing Associates. (7th printing, 1985). . (''Crotalus atrox'') is a rattlesnake species and member of the viper family, ... ('' Crotalus atrox''). References External links * {{Portal bar, Biology, border=no EC 3.4.24 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimerelysin I
Trimerelysin I (, ''Trimeresurus metalloendopeptidase I'', ''hemorrhagic proteinase HR1A'', ''hemorrhagic metalloproteinase HR1A'', ''metalloproteinase HR1A'') is an enzyme. This enzyme catalyses the following chemical reaction : Cleavage of only two bonds His10-Leu and Ala14-Leu in the insulin B chain This endopeptidase is present in the venom of the habu snake (''Trimeresurus flavoviridis The Okinawa habuU.S. Navy (1991). ''Poisonous Snakes of the World''. New York: US Government / Dover Publications Inc. 203 pp. . (''Protobothrops flavoviridis'') is a species of pit viper endemic to the Ryukyu Islands of Japan. No subspecies are ...''). References External links * {{Portal bar, Biology, border=no EC 3.4.24 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colubroidea
Colubroidea is a superfamily of snakes in the clade Colubroides that includes Colubridae, with some studies splitting Colubridae into multiple families that make up Colubroidea. Historically, Colubroidea also included other caenophidian snakes such as cobras and vipers, as these snakes form a clade. However these groups are now divided into several distinct, but related, families. Zaher et al. (2009) proposed to redefine Colubroidea for colubrids and related families, while designating Colubroides as the group containing vipers and cobras as well as colubroids. The ReptileDatabase considers Colubroidea to be composed of Colubridae and the members of its sister group, Elapoidea, and does not recognize the division of Colubridae into multiple families. Classification Phylogeny Families and Subfamilies Usual taxonomy: * Family: Colubridae Nicolaus Michael Oppel, Oppel, 1811 ** Subfamily: Grayiinae Günther, 1858 ** Subfamily: Calamariinae Bonaparte, 1838 ** Subfamily: Ahaetullina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Family
A protein family is a group of evolutionarily related proteins. In many cases, a protein family has a corresponding gene family, in which each gene encodes a corresponding protein with a 1:1 relationship. The term "protein family" should not be confused with family as it is used in taxonomy. Proteins in a family descend from a common ancestor and typically have similar three-dimensional structures, functions, and significant sequence similarity. Sequence similarity (usually amino-acid sequence) is one of the most common indicators of homology, or common evolutionary ancestry. Some frameworks for evaluating the significance of similarity between sequences use sequence alignment methods. Proteins that do not share a common ancestor are unlikely to show statistically significant sequence similarity, making sequence alignment a powerful tool for identifying the members of protein families. Families are sometimes grouped together into larger clades called superfamilies based on st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coagulation
Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a thrombus, blood clot. It results in hemostasis, the cessation of blood loss from a damaged vessel, followed by repair. The process of coagulation involves Platelet-activating factor, activation, Cell adhesion, adhesion and aggregation of platelets, as well as deposition and maturation of fibrin. Coagulation begins almost instantly after an injury to the endothelium that lines a blood vessel. Exposure of blood to the subendothelial space initiates two processes: changes in platelets, and the exposure of subendothelial Tissue factor, platelet tissue factor to coagulation factor VII, which ultimately leads to cross-linked fibrin formation. Platelets immediately form a plug at the site of injury; this is called ''primary hemostasis. Secondary hemostasis'' occurs simultaneously: additional coagulation factors beyond factor VII (#Coagulation factors, listed below) respond in a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
