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Vitamin K-dependent Protein
{{Unreferenced, date=May 2019, bot=noref (GreenC bot) A Vitamin K-dependent protein (VKDP) is a protein that can bind calcium ions but only after being carboxylated at a certain glutamic residue. This carboxylation, said to activate the protein, is facilitated by some form of vitamin K1 or vitamin K2. The relevant part of a vitamin K-dependent protein is a Gla domain, and such a protein is informally called a Gla protein. Some Gla proteins have "Gla" in their name, for example Matrix Gla protein, but many don't, such as osteocalcin Osteocalcin, also known as bone gamma-carboxyglutamic acid-containing protein (BGLAP), is a small (49-amino-acid) noncollagenous protein hormone found in bone and dentin, first identified as a calcium-binding protein. Because osteocalcin has g .... Proteins Vitamin K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and the third most abundant metal, after iron and aluminium. The most common calcium compound on Earth is calcium carbonate, found in limestone and the fossilised remnants of early sea life; gypsum, anhydrite, fluorite, and apatite are also sources of calcium. The name derives from Latin ''calx'' "lime", which was obtained from heating limestone. Some calcium compounds were known to the ancients, though their chemistry was unknown until the seventeenth century. Pure calcium was isolated in 1808 via electrolysis of its oxide by Humphry Davy, who named the element. Calcium compounds are widely used in many industries: in foods and ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboxylation
Carboxylation is a chemical reaction in which a carboxylic acid is produced by treating a substrate with carbon dioxide. The opposite reaction is decarboxylation. In chemistry, the term carbonation is sometimes used synonymously with carboxylation, especially when applied to the reaction of carbanionic reagents with CO2. More generally, carbonation usually describes the production of carbonates. Organic chemistry Carboxylation is a standard conversion in organic chemistry. Specifically carbonation (i.e. carboxylation) of Grignard reagents and organolithium compounds is a classic way to convert organic halides into carboxylic acids. Sodium salicylate, precursor to aspirin, is commercially prepared by treating sodium phenolate (the sodium salt of phenol) with carbon dioxide at high pressure (100 atm) and high temperature (390 K) – a method known as the Kolbe-Schmitt reaction. Acidification of the resulting salicylate salt gives salicylic acid. : Many detailed procedures are de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glutamic Acid
Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can synthesize enough for its use. It is also the most abundant excitatory neurotransmitter in the vertebrate nervous system. It serves as the precursor for the synthesis of the inhibitory gamma-aminobutyric acid (GABA) in GABA-ergic neurons. Its molecular formula is . Glutamic acid exists in three optically isomeric forms; the dextrorotatory -form is usually obtained by hydrolysis of gluten or from the waste waters of beet-sugar manufacture or by fermentation.Webster's Third New International Dictionary of the English Language Unabridged, Third Edition, 1971. Its molecular structure could be idealized as HOOC−CH()−()2−COOH, with two carboxyl groups −COOH and one amino group −. However, in the solid state and mildly acidic water solut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytomenadione
Phytomenadione, also known as vitamin K1 or phylloquinone, is a vitamin found in food and used as a dietary supplement. It is on the World Health Organization's List of Essential Medicines. As a supplement it is used to treat certain bleeding disorders. This includes warfarin overdose, vitamin K deficiency, and obstructive jaundice. It is also recommended to prevent and treat vitamin K deficiency bleeding in infants. Use is typically recommended by mouth, intramuscular injection or injection under the skin. When given by injection benefits are seen within two hours. Many countries in the world choose intramuscular injections in newborn to keep them safe from severe bleeding (VKDB). It is considered a safe treatment and saves many children from death and severe neurologic deficit every year. Side effects when given by injection may include pain at the site of injection. Severe allergic reactions may occur when it is injected into a vein or muscle, but this has mainly happe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitamin K2
Vitamin K2 or menaquinone (MK) () is one of three types of vitamin K, the other two being vitamin K1 ( phylloquinone) and K3 ( menadione). K2 is both a tissue and bacterial product (derived from vitamin K1 in both cases) and is usually found in animal products or fermented foods. The number ''n'' of isoprenyl units in their side chain differs and ranges from 4 to 13, hence Vitamin K2 consists of various forms. It is indicated as a suffix (-n), e. g. MK-7 or MK-9. The most common in the human diet is the short-chain, water-soluble menatetrenone (MK-4), which is usually produced by tissue and/or bacterial conversion of vitamin K1, and is commonly found in animal products. It is known that production of MK-4 from dietary plant vitamin K1 can be accomplished by animal tissues alone, as it proceeds in germ-free rodents. However, at least one published study concluded that "MK-4 present in food does not contribute to the vitamin K status as measured by serum vitamin K levels. MK-7, ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gla Domain
Vitamin K-dependent carboxylation/gamma-carboxyglutamic (GLA) domain is a protein domain that contains post-translational modifications of many glutamate residues by vitamin K-dependent carboxylation to form γ-carboxyglutamate (Gla). Proteins with this domain are known informally as Gla proteins. The Gla residues are responsible for the high-affinity binding of calcium ions. The GLA domain binds calcium ions by chelating them between two carboxylic acid residues. These residues are part of a region that starts at the N-terminal extremity of the mature form of Gla proteins, and that ends with a conserved aromatic residue. This results in a conserved Gla-x(3)-Gla-x-Cys motif that is found in the middle of the domain, and which seems to be important for substrate recognition by the carboxylase. The 3D structures of several Gla domains have been solved. Calcium ions induce conformational changes in the Gla domain and are necessary for the Gla domain to fold properly. A common struct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matrix Gla Protein
Matrix Gla protein (MGP) is member of a family of vitamin K2 dependent, Gla-containing proteins. MGP has a high affinity binding to calcium ions, similar to other Gla-containing proteins. The protein acts as an inhibitor of vascular mineralization and plays a role in bone organization. MGP is found in a number of body tissues in mammals, birds, and fish. Its mRNA is present in bone, cartilage, heart, and kidney. It is present in bone together with the related vitamin K2-dependent protein osteocalcin. In bone, its production is increased by vitamin D. Genetics The ''MGP'' was linked to the short arm of chromosome 12 in 1990. Its mRNA sequence length is 585 bases long in humans. Physiology MGP and osteocalcin are both calcium-binding proteins that may participate in the organisation of bone tissue. Both have glutamate residues that are post-translationally carboxylated by the enzyme gamma-glutamyl carboxylase in a reaction that requires Vitamin K hydroquinone. Role in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteocalcin
Osteocalcin, also known as bone gamma-carboxyglutamic acid-containing protein (BGLAP), is a small (49-amino-acid) noncollagenous protein hormone found in bone and dentin, first identified as a calcium-binding protein. Because osteocalcin has gla domains, its synthesis is vitamin K dependent. In humans, osteocalcin is encoded by the ''BGLAP'' gene. Its receptors include GPRC6A, GPR158, and possibly a third, yet-to-be-identified receptor. There is evidence that GPR37 might be the third osteocalcin receptor. Function Osteocalcin is secreted solely by osteoblasts and thought to play a role in the body's metabolic regulation. In its carboxylated form it binds calcium directly and thus concentrates in bone. In its uncarboxylated form, osteocalcin acts as a hormone in the body, signalling in the pancreas, fat, muscle, testes, and brain. * In the pancreas, osteocalcin acts on beta cells, causing beta cells in the pancreas to release more insulin. * In fat cells, osteocalcin tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteins
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
