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Tosyl Phenylalanyl Chloromethyl Ketone
Tosyl phenylalanyl chloromethyl ketone (TPCK) is a protease inhibitor. Its structural formula is 1-chloro-3-tosylamido-4-phenyl-2-butanone. Uses TPCK is an irreversible inhibitor of chymotrypsin. Also inhibits some cysteine proteases such as caspase, papain, bromelain or ficin. It does not inhibit trypsin or zymogens. TPCK is observed covalently bound in the active site of Caspase 3 in the crystal structure of the complex solved in 2010. Acta Crystallogr F v67 p 842. PDB Entry The chloromethyl group reacts with the active site cysteine to form a covalent bond with the loss of the chlorine. TPCK is chosen for the chemical labelling of active histidine in enzyme analysis. The phenylalanine moiety is bound to the enzyme because of specificity for aromatic amino acid residues at the active site (as in |
Protease Inhibitor (biology)
In biology and biochemistry, protease inhibitors, or antiproteases, are molecules that inhibit the function of proteases (enzymes that aid the breakdown of proteins). Many naturally occurring protease inhibitors are proteins. In medicine, ''protease inhibitor'' is often used interchangeably with alpha 1-antitrypsin (A1AT, which is abbreviated PI for this reason). A1AT is indeed the protease inhibitor most often involved in disease, namely in alpha-1 antitrypsin deficiency. Classification Protease inhibitors may be classified either by the type of protease they inhibit, or by their mechanism of action. In 2004 Rawlings and colleagues introduced a classification of protease inhibitors based on similarities detectable at the level of amino acid sequence. This classification initially identified 48 families of inhibitors that could be grouped into 26 related superfamily (or clans) by their structure. According to the MEROPS database there are now 81 families of inhibitors. These ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ficin
Ficain also known as ficin, debricin, or higueroxyl delabarre () is a proteolytic enzyme extracted from the latex sap from the stems, leaves, and unripe fruit of the American wild fig tree ''Ficus insipida''. Ficain was originally called ficin, and ficin was originally a mixture of closely related cysteine endopeptidases produced from any species of the genus ''Ficus'', before the terminology was restricted to a specific cysteine endopeptidase enzyme from a specific species. Cysteine endopeptidases are a group of enzymes that also include the more distantly related papain derived from papaya latex, bromelase (bromelain) extracted from pineapple stem, calpain, caspases, cathepsin B, and chymopapain. Cysteine endopeptidases with similar properties known generically as ficins are present in other members of the genus ''Ficus'', and many species appear to contain multiple types of these enzymes. Somewhat confusingly, the terms ficain and ficin are often treated as synonyms. Ficain is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protease Inhibitors
Protease inhibitors (PIs) are medications that act by interfering with enzymes that cleave proteins. Some of the most well known are antiviral drugs widely used to treat HIV/AIDS and hepatitis C. These protease inhibitors prevent viral replication by selectively binding to viral proteases (e.g. HIV-1 protease) and blocking proteolytic cleavage of protein precursors that are necessary for the production of infectious viral particles. Protease inhibitors that have been developed and are currently used in clinical practice include: * Antiretroviral HIV-1 protease inhibitors—class stem ** Amprenavir ** Atazanavir ** Darunavir ** Fosamprenavir ** Indinavir ** Lopinavir ** Nelfinavir ** Ritonavir ** Saquinavir ** Tipranavir * Hepatitis C virus NS3/ 4A protease inhibitors—class stem ** Asunaprevir ** Boceprevir ** Grazoprevir ** Glecaprevir ** Paritaprevir ** Simeprevir ** Telaprevir * Severe acute respiratory syndrome coronavirus 2 3-chymotrypsin-like p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SARS-CoV-2
Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the ongoing COVID-19 pandemic. The virus previously had a Novel coronavirus, provisional name, 2019 novel coronavirus (2019-nCoV), and has also been called the human coronavirus 2019 (HCoV-19 or hCoV-19). First identified in the city of Wuhan, Hubei, China, the World Health Organization declared the outbreak a public health emergency of international concern on January 30, 2020, and a pandemic on March 11, 2020. SARS‑CoV‑2 is a positive-sense single-stranded RNA virus that is Contagious disease, contagious in humans. SARS‑CoV‑2 is a virus of the species ''severe acute respiratory syndrome–related coronavirus'' (SARSr-CoV), related to the Severe acute respiratory syndrome coronavirus 1, SARS-CoV-1 virus that caused the 2002–2004 SARS outbreak. Despite its close relation to SARS-CoV-1, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avian Influenza
Avian influenza, known informally as avian flu or bird flu, is a variety of influenza caused by viruses adapted to birds.Chapter Two : Avian Influenza by Timm C. Harder and Ortrud Werner in ''Influenza Report 2006'' CDC has a showing the relationship between dozens of highly varieties of the Z genotype of avian flu virus H5N1 and ancestral strains. The type with the g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tissue Culture
Tissue culture is the growth of tissues or cells in an artificial medium separate from the parent organism. This technique is also called micropropagation. This is typically facilitated via use of a liquid, semi-solid, or solid growth medium, such as broth or agar. Tissue culture commonly refers to the culture of animal cells and tissues, with the more specific term plant tissue culture being used for plants. The term "tissue culture" was coined by American pathologist Montrose Thomas Burrows. Historical use In 1885 Wilhelm Roux removed a section of the medullary plate of an embryonic chicken and maintained it in a warm saline solution for several days, establishing the basic principle of tissue culture. In 1907 the zoologist Ross Granville Harrison demonstrated the growth of frog embryonic cells that would give rise to nerve cells in a medium of clotted lymph. In 1913, E. Steinhardt, C. Israeli, and R. A. Lambert grew vaccinia virus in fragments of guinea pig corneal tiss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequence Of Proteases - Chymotrypsin A - Trypsin - Elastase
In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called ''elements'', or ''terms''). The number of elements (possibly infinite) is called the ''length'' of the sequence. Unlike a set, the same elements can appear multiple times at different positions in a sequence, and unlike a set, the order does matter. Formally, a sequence can be defined as a function from natural numbers (the positions of elements in the sequence) to the elements at each position. The notion of a sequence can be generalized to an indexed family, defined as a function from an ''arbitrary'' index set. For example, (M, A, R, Y) is a sequence of letters with the letter 'M' first and 'Y' last. This sequence differs from (A, R, M, Y). Also, the sequence (1, 1, 2, 3, 5, 8), which contains the number 1 at two different positions, is a valid sequence. Sequences can be ''finite'', as in these examples, or ''infini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal Structure
In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions or molecules in a crystalline material. Ordered structures occur from the intrinsic nature of the constituent particles to form symmetric patterns that repeat along the principal directions of three-dimensional space in matter. The smallest group of particles in the material that constitutes this repeating pattern is the unit cell of the structure. The unit cell completely reflects the symmetry and structure of the entire crystal, which is built up by repetitive translation of the unit cell along its principal axes. The translation vectors define the nodes of the Bravais lattice. The lengths of the principal axes, or edges, of the unit cell and the angles between them are the lattice constants, also called ''lattice parameters'' or ''cell parameters''. The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of partic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caspase 3
Caspase-3 is a caspase protein that interacts with caspase-8 and caspase-9. It is encoded by the ''CASP3'' gene. ''CASP3'' orthologs have been identified in numerous mammals for which complete genome data are available. Unique orthologs are also present in birds, lizards, lissamphibians, and teleosts. The CASP3 protein is a member of the cysteine-aspartic acid protease (caspase) family. Sequential activation of caspases plays a central role in the execution-phase of cell apoptosis. Caspases exist as inactive proenzymes that undergo proteolytic processing at conserved aspartic residues to produce two subunits, large and small, that dimerize to form the active enzyme. This protein cleaves and activates caspases 6 and 7; and the protein itself is processed and activated by caspases 8, 9, and 10. It is the predominant caspase involved in the cleavage of amyloid-beta 4A precursor protein, which is associated with neuronal death in Alzheimer's disease. Alternative splicing of thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zymogens
In biochemistry, a zymogen (), also called a proenzyme (), is an inactive precursor of an enzyme. A zymogen requires a biochemical change (such as a hydrolysis reaction revealing the active site, or changing the configuration to reveal the active site) for it to become an active enzyme. The biochemical change usually occurs in Golgi bodies, where a specific part of the precursor enzyme is cleaved in order to activate it. The inactivating piece which is cleaved off can be a peptide unit, or can be independently-folding domains comprising more than 100 residues. Although they limit the enzyme's ability, these N-terminal extensions of the enzyme or a “prosegment” often aid in the stabilization and folding of the enzyme they inhibit. The pancreas secretes zymogens partly to prevent the enzymes from digesting proteins in the cells in which they are synthesised. Enzymes like pepsin are created in the form of pepsinogen, an inactive zymogen. Pepsinogen is activated when chie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trypsin
Trypsin is an enzyme in the first section of the small intestine that starts the digestion of protein molecules by cutting these long chains of amino acids into smaller pieces. It is a serine protease from the PA clan superfamily, found in the digestive system of many vertebrates, where it hydrolyzes proteins. Trypsin is formed in the small intestine when its proenzyme form, the trypsinogen produced by the pancreas, is activated. Trypsin cuts peptide chains mainly at the carboxyl side of the amino acids lysine or arginine. It is used for numerous biotechnological processes. The process is commonly referred to as trypsin proteolysis or trypsinization, and proteins that have been digested/treated with trypsin are said to have been trypsinized. Trypsin was discovered in 1876 by Wilhelm Kühne and was named from the Ancient Greek word for rubbing since it was first isolated by rubbing the pancreas with glycerin. Function In the duodenum, trypsin catalyzes the hydro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromelain
Bromelain is an enzyme extract derived from the stems of pineapples, although it exists in all parts of the fresh pineapple. The extract has a history of folk medicine use. As an ingredient, it is used in cosmetics, as a topical medication, and as a meat tenderizer. The term "bromelain" may refer to either of two protease enzymes extracted from the plants of the family Bromeliaceae, or it may refer to a combination of those enzymes along with other compounds produced in an extract. Bromelain enzymes are called ''fruit bromelain'' and ''stem bromelain''. Although tested in a variety of folk medicine and research models for its possible efficacy against diseases, bromelain has only one approved clinical application issued in 2012 by the European Medicines Agency a topical medication called '' NexoBrid'', used to remove dead tissue in severe skin burns. Extract components Bromelain extract is a mixture of protein-digesting (proteolytic) enzymes and several other substances in s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
