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L-Proline
Proline (symbol Pro or P) is an organic acid classed as a proteinogenic amino acid (used in the biosynthesis of proteins), although it does not contain the amino group but is rather a secondary amine. The secondary amine nitrogen is in the protonated form (NH2+) under biological conditions, while the carboxyl group is in the deprotonated −COO− form. The "side chain" from the α carbon connects to the nitrogen forming a pyrrolidine loop, classifying it as a aliphatic amino acid. It is non-essential in humans, meaning the body can synthesize it from the non-essential amino acid L- glutamate. It is encoded by all the codons starting with CC (CCU, CCC, CCA, and CCG). Proline is the only proteinogenic secondary amino acid which is a secondary amine, as the nitrogen atom is attached both to the α-carbon and to a chain of three carbons that together form a five-membered ring. History and etymology Proline was first isolated in 1900 by Richard Willstätter who obtained the amin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha amino acids appear in the genetic code. Amino acids can be classified according to the locations of the core structural functional groups, as Alpha and beta carbon, alpha- , beta- , gamma- or delta- amino acids; other categories relate to Chemical polarity, polarity, ionization, and side chain group type (aliphatic, Open-chain compound, acyclic, aromatic, containing hydroxyl or sulfur, etc.). In the form of proteins, amino acid '' residues'' form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skeletal Formula
The skeletal formula, or line-angle formula or shorthand formula, of an organic compound is a type of molecular structural formula that serves as a shorthand representation of a molecule's bonding and some details of its molecular geometry. A skeletal formula shows the skeletal structure or skeleton of a molecule, which is composed of the skeletal atoms that make up the molecule. It is represented in two dimensions, as on a piece of paper. It employs certain conventions to represent carbon and hydrogen atoms, which are the most common in organic chemistry. An early form of this representation was first developed by organic chemist August Kekulé, while the modern form is closely related to and influenced by the Lewis structure of molecules and their valence electrons. Hence they are sometimes termed Kekulé structures or Lewis–Kekulé structures. Skeletal formulae have become ubiquitous in organic chemistry, partly because they are relatively quick and simple to draw, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Amino Acid
Secondary amino acids are amino acids which do not contain the amino group but is rather a secondary amine. Secondary amino acids can be classified to cyclic acids such as proline and acyclic N-substituted amino acids. In nature, proline, hydroxyproline, pipecolic acid and sarcosine are well-known secondary amino acids. Proline is the only proteinogenic secondary amino acids. Other secondary amino acids are non-proteinogenic amino acids. In protein, hydroxyproline is incorporated into protein by hydroxylation of proline. Pipecolic acid, a heavier analog of proline, is found in efrapeptin. Sarcosine is a N-methylized glycine so its methyl group is used in many biochemical reactions. Azetidine-2-carboxylic acid, which is a smaller homolog of proline in plants. Properties Proline and its higher homolog pipecolic acid affect the secondary structure of protein. D-alpha-amino acid - L-alpha-amino acid sequence can induce beta hairpin. It suggested that acyclic secondary amino aci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornithine Aminotransferase
Ornithine aminotransferase (OAT) is an enzyme which is encoded in human by the OAT gene located on chromosome 10. The OAT involved in the ultimate formation of the non-essential amino acid proline from the amino acid ornithine. Ornithine aminotransferase forms the initial intermediate in this process. It catalyzes the reverse reaction as well, and is therefore essential in creating ornithine from the starting substrate proline. Structure The OAT gene encodes for a protein that is approximately 46 kDa in size. The OAT protein is expressed primarily in the liver and the kidney but also in the brain and the retina. The OAT protein is localized to the mitochondrion within the cells where it is expressed. The structure of the OAT protein has been resolved using X-ray crystallography and shows similarity to other subgroup 2 aminotransferases such as dialkyglucine decarboxylatse. The OAT protein functions as a dimer and each monomer consists of a large domain, which contributes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornithine
Ornithine is a non-proteinogenic amino acid that plays a role in the urea cycle. Ornithine is abnormally accumulated in the body in ornithine transcarbamylase deficiency. The radical is ornithyl. Role in urea cycle L-Ornithine is one of the products of the action of the enzyme arginase on L-arginine, creating urea. Therefore, ornithine is a central part of the urea cycle, which allows for the disposal of excess nitrogen. Ornithine is recycled and, in a manner, is a catalyst. First, ammonia is converted into carbamoyl phosphate (). Ornithine is converted into a urea derivative at the δ (terminal) nitrogen by carbamoyl phosphate synthetase. Another nitrogen is added from aspartate, producing the denitrogenated fumarate, and the resulting arginine (a guanidinium compound) is hydrolysed back to ornithine, producing urea. The nitrogens of urea come from the ammonia and aspartate, and the nitrogen in ornithine remains intact. Ornithine is not an amino acid coded for by DNA, that is, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrroline-5-carboxylate Reductase
In enzymology, a pyrroline-5-carboxylate reductase () is an enzyme that catalyzes the chemical reaction :L-proline + NAD(P)+ \rightleftharpoons 1-pyrroline-5-carboxylate + NAD(P)H + H+ The 3 substrates of this enzyme are L-proline, NAD+, and NADP+, whereas its 4 products are 1-pyrroline-5-carboxylate, NADH, NADPH, and H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH group of donors with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is L-proline:NAD(P)+ 5-oxidoreductase. Other names in common use include proline oxidase, L-proline oxidase, 1-pyrroline-5-carboxylate reductase, NADPH-L-Delta1-pyrroline carboxylic acid reductase, and L-proline-NAD(P)+ 5-oxidoreductase. This enzyme participates in arginine and proline metabolism. Structural studies As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes , , , , and . Human genes * PYCR1, nuclear gene for mit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1-pyrroline-5-carboxylic Acid
1-Pyrroline-5-carboxylic acid (systematic name 3,4-dihydro-2H-pyrrole-2-carboxylic acid) is a cyclic imino acid. Its conjugate base and anion is 1-pyrroline-5-carboxylate (P5C). In solution, P5C is in spontaneous equilibrium with glutamate-5-semialdhyde (GSA). The stereoisomer (''S'')-1-pyrroline-5-carboxylate (also referred to as L-P5C) is an intermediate metabolite in the biosynthesis and degradation of proline and arginine. In prokaryotic proline biosynthesis, GSA is synthesized from γ-glutamyl phosphate by the enzyme γ-glutamyl phosphate reductase. In most eukaryotes, GSA is synthesised from the amino acid glutamate by the bifunctional enzyme 1-pyrroline-5-carboxylate synthase (P5CS). The human P5CS is encoded by the ''ALDH18A1'' gene. The enzyme pyrroline-5-carboxylate reductase converts P5C into proline In proline degradation, the enzyme proline dehydrogenase produces P5C from proline, and the enzyme 1-pyrroline-5-carboxylate dehydrogenase converts GSA to glu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glutamate-5-semialdehyde Dehydrogenase
In enzymology, a glutamate-5-semialdehyde dehydrogenase () is an enzyme that catalyzes the chemical reaction :L-glutamate 5-semialdehyde + phosphate + NADP+ \rightleftharpoons L-glutamyl 5-phosphate + NADPH + H+ The 3 substrates of this enzyme are L-glutamate 5-semialdehyde, phosphate, and NADP+, whereas its 3 products are L-glutamyl 5-phosphate, NADPH, and H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on the aldehyde or oxo group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is L-glutamate-5-semialdehyde:NADP+ 5-oxidoreductase (phosphorylating). Other names in common use include beta-glutamylphosphate reductase, gamma-glutamyl phosphate reductase, beta-glutamylphosphate reductase, glutamate semialdehyde dehydrogenase, and glutamate-gamma-semialdehyde dehydrogenase. This enzyme participates in urea cycle and metabolism of amino groups. Structural studies As of late 2007, 3 structures A struc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glutamate 5-kinase
In enzymology, a glutamate 5-kinase () is an enzyme that catalyzes the chemical reaction :ATP + L-glutamate \rightleftharpoons ADP + L-glutamate 5-phosphate Thus, the two substrates of this enzyme are ATP and L-glutamate, whereas its two products are ADP and L-glutamate 5-phosphate. This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing groups ( phosphotransferases) with a carboxy group as acceptor. The systematic name of this enzyme class is ATP:L-glutamate 5-phosphotransferase. Other names in common use include ATP-L-glutamate 5-phosphotransferase, ATP:gamma-L-glutamate phosphotransferase, gamma-glutamate kinase, gamma-glutamyl kinase, and glutamate kinase. This enzyme participates in urea cycle and metabolism of amino groups. Structural studies As of late 2007, 3 structures A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glutamate-5-semialdehyde
Glutamate-5-semialdehyde is a non-proteinogenic amino acid involved in both the biosynthesis and degradation of proline and arginine (via ornithine), as well as in the biosynthesis of antibiotics, such as carbapenem Carbapenems are a class of very effective antibiotic agents most commonly used for the treatment of severe bacterial infections. This class of antibiotics is usually reserved for known or suspected multidrug-resistant (MDR) bacterial infections. ...s. It is synthesized by the reduction of glutamyl-5-phosphate by glutamate-5-semialdehyde dehydrogenase. See also * Glutamate-1-semialdehyde References {{Amino acid metabolism intermediates Amino acids Aldehydes Aldehydic acids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biosynthesis
Biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. This process often consists of metabolic pathways. Some of these biosynthetic pathways are located within a single cellular organelle, while others involve enzymes that are located within multiple cellular organelles. Examples of these biosynthetic pathways include the production of lipid membrane components and nucleotides. Biosynthesis is usually synonymous with anabolism. The prerequisite elements for biosynthesis include: precursor compounds, chemical energy (e.g. ATP), and catalytic enzymes which may require coenzymes (e.g.NADH, NADPH). These elements create monomers, the building blocks for macromolecules. Some important biological macromolecules include: proteins, which are composed of amino acid monomers joined via pepti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Casein
Casein ( , from Latin ''caseus'' "cheese") is a family of related phosphoproteins ( αS1, aS2, β, κ) that are commonly found in mammalian milk, comprising about 80% of the proteins in cow's milk and between 20% and 60% of the proteins in human milk. Sheep and buffalo milk have a higher casein content than other types of milk with human milk having a particularly low casein content. Casein has a wide variety of uses, from being a major component of cheese, to use as a food additive. The most common form of casein is sodium caseinate. In milk, casein undergoes phase separation to form colloidal casein micelles, a type of secreted biomolecular condensate. As a food source, casein supplies amino acids, carbohydrates, and two essential elements, calcium and phosphorus. Composition Casein contains a high number of proline amino acids which hinder the formation of common secondary structural motifs of proteins. There are also no disulfide bridges. As a result, it has rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
