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Venombin AB
Venombin AB (, ''gabonase'', ''okinaxobin II'', ''Bitis gabonica venom serine proteinase'', ''afaâ'', ''cytin'') is an enzyme. This enzyme catalyses the following chemical reaction : Selective cleavage at Arg- bonds in fibrinogen to form fibrin and release fibrinopeptides A and B This enzyme is isolated from the venom of the Gaboon viper ''Bitis gabonica The Gaboon viper (''Bitis gabonica''), also called the Gaboon adder, is a viper species found in the rainforests and savannas of sub-Saharan Africa.McDiarmid RW, Campbell JA, Touré T. 1999. ''Snake Species of the World: A Taxonomic and Geograp ...''. References External links * {{Portal bar, Biology, border=no EC 3.4.21 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalysis
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst. Catalysis may be classified as either homogeneous, whose components are dispersed in the same phase (usually gaseous or liquid) as the reactant, or heterogeneous, whose components are not in the same phase. Enzymes and other biocatalysts are often considered as a third category. Catalysis is ubiquitous in chemical industry of all kinds. Estimates are that 90% of all commercially produced chemical products involve catalysts at some s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Reaction
A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the Atomic nucleus, nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive Chemical element, elements where both electronic and nuclear changes can occur. The substance (or substances) initially involved in a chemical reaction are called reagent, reactants or reagents. Chemical reactions are usually characterized by a chemical change, and they yield one or more Product (chemistry), products, which usually have properties different from the reactants. Reactions often consist of a sequence o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fibrinogen
Fibrinogen (factor I) is a glycoprotein complex, produced in the liver, that circulates in the blood of all vertebrates. During tissue and vascular injury, it is converted enzymatically by thrombin to fibrin and then to a fibrin-based blood clot. Fibrin clots function primarily to occlude blood vessels to stop bleeding. Fibrin also binds and reduces the activity of thrombin. This activity, sometimes referred to as antithrombin I, limits clotting. Fibrin also mediates blood platelet and endothelial cell spreading, tissue fibroblast proliferation, capillary tube formation, and angiogenesis and thereby promotes revascularization and wound healing. Reduced and/or dysfunctional fibrinogens occur in various congenital and acquired human fibrinogen-related disorders. These disorders represent a group of rare conditions in which individuals may present with severe episodes of pathological bleeding and thrombosis; these conditions are treated by supplementing blood fibrinogen levels an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fibrin
Fibrin (also called Factor Ia) is a fibrous, non-globular protein involved in the clotting of blood. It is formed by the action of the protease thrombin on fibrinogen, which causes it to polymerize. The polymerized fibrin, together with platelets, forms a hemostatic plug or clot over a wound site. When the lining of a blood vessel is broken, platelets are attracted, forming a platelet plug. These platelets have thrombin receptors on their surfaces that bind serum thrombin molecules, which in turn convert soluble fibrinogen in the serum into fibrin at the wound site. Fibrin forms long strands of tough insoluble protein that are bound to the platelets. Factor XIII completes the cross-linking of fibrin so that it hardens and contracts. The cross-linked fibrin forms a mesh atop the platelet plug that completes the clot. Fibrin was discovered by Marcello Malpighi in 1666. Role in disease Excessive generation of fibrin due to activation of the coagulation cascade leads to thrombos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fibrinopeptide A
The fibrinopeptides, fibrinopeptide A (FpA) and fibrinopeptide B (FpB), are peptides which are located in the central region of the fibrous glycoprotein fibrinogen (factor I) and are cleaved by the enzyme thrombin (factor IIa) to convert fibrinogen into covalently-linked fibrin (factor IA) monomers. The N-terminal FpA is cleaved from the Aα chains of fibrinogen and FpB from the Bβ chains of fibrinogen, with FpA released before FpB. Subsequent to their formation, fibrin monomers are converted to cross-linked fibrin polymers by the action of thrombin-activated factor XIII (fibrin stabilizing factor), and these fibrin polymers form the backbone of a thrombus (blood clot). Hence, the fibrinopeptides are sensitive markers of fibrinogenesis (fibrin generation), thrombin activity, and coagulation. FpA is a 16-amino acid peptide. The half-life of FpA is very short at approximately 3 to 5 minutes. Hence, FpA levels provide a relatively transient measure of coagulation activ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fibrinopeptide B
The fibrinopeptides, fibrinopeptide A (FpA) and fibrinopeptide B (FpB), are peptides which are located in the central region of the fibrous glycoprotein fibrinogen (factor I) and are cleaved by the enzyme thrombin (factor IIa) to convert fibrinogen into covalently-linked fibrin (factor IA) monomers. The N-terminal FpA is cleaved from the Aα chains of fibrinogen and FpB from the Bβ chains of fibrinogen, with FpA released before FpB. Subsequent to their formation, fibrin monomers are converted to cross-linked fibrin polymers by the action of thrombin-activated factor XIII (fibrin stabilizing factor), and these fibrin polymers form the backbone of a thrombus (blood clot). Hence, the fibrinopeptides are sensitive markers of fibrinogenesis (fibrin generation), thrombin activity, and coagulation. FpA is a 16-amino acid peptide. The half-life of FpA is very short at approximately 3 to 5 minutes. Hence, FpA levels provide a relatively transient measure of coagulation activati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venom
Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a stinger, in a process called envenomation. Venom is often distinguished from poison, which is a toxin that is passively delivered by being ingested, inhaled, or absorbed through the skin, and toxungen, which is actively transferred to the external surface of another animal via a physical delivery mechanism. Venom has evolved in terrestrial and marine environments and in a wide variety of animals: both predators and prey, and both vertebrates and invertebrates. Venoms kill through the action of at least four major classes of toxin, namely necrotoxins and cytotoxins, which kill cells; neurotoxins, which affect nervous systems; myotoxins, which damage muscles; and haemotoxins, which disrupt blood clotting. Venomous animals cause tens of thousa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gaboon Viper
The Gaboon viper (''Bitis gabonica''), also called the Gaboon adder, is a viper species found in the rainforests and savannas of sub-Saharan Africa.McDiarmid RW, Campbell JA, Touré T. 1999. ''Snake Species of the World: A Taxonomic and Geographic Reference, Volume 1''. Herpetologists' League. 511 pp. (series). (volume). Like all other vipers, it is venomous. It is the largest member of the genus ''Bitis'',Spawls S, Branch B. 1995. ''The Dangerous Snakes of Africa''. Ralph Curtis Books. Dubai: Oriental Press. 192 pp. and it has the longest fangs of any venomous snake – up to 2 inches (5 cm) in length – and the highest venom yield of any snake. No subspecies are recognized. Taxonomy The Gaboon viper was described in 1854 as ''Echidna Gabonica''. Lenk ''et al.'' (1999) discovered genetic differences between the two conventionally recognized subspecies of ''B. g. gabonica'' and ''B. g. rhinoceros''. According to their research, these two subspecies are as geneticall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bitis Gabonica
The Gaboon viper (''Bitis gabonica''), also called the Gaboon adder, is a viper species found in the rainforests and savannas of sub-Saharan Africa.McDiarmid RW, Campbell JA, Touré T. 1999. ''Snake Species of the World: A Taxonomic and Geographic Reference, Volume 1''. Herpetologists' League. 511 pp. (series). (volume). Like all other vipers, it is venomous. It is the largest member of the genus ''Bitis'',Spawls S, Branch B. 1995. ''The Dangerous Snakes of Africa''. Ralph Curtis Books. Dubai: Oriental Press. 192 pp. and it has the longest fangs of any venomous snake – up to 2 inches (5 cm) in length – and the highest venom yield of any snake. No subspecies are recognized. Taxonomy The Gaboon viper was described in 1854 as ''Echidna Gabonica''. Lenk ''et al.'' (1999) discovered genetic differences between the two conventionally recognized subspecies of ''B. g. gabonica'' and ''B. g. rhinoceros''. According to their research, these two subspecies are as geneticall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
