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Leucines
The leucines are primarily the four isomeric amino acids: leucine, isoleucine, ''tert''-leucine ( terleucine, pseudoleucine) and norleucine. Being compared with the four butanols, they could be classified as butyl-substituted glycines; they represent all four possible variations. Leucine and isoleucine belong to the proteinogenic amino acids; the others are non-natural. Isomers Including the stereoisomers, six further isomers could be added: D-leucine, D-isoleucine, L-alloisoleucine, D-alloisoleucine, D-''tert''-leucine and D-norleucine. Derivatives Cycloleucine could be classified as a cyclic derivative of norleucine. With a cyclopentane-ring, it has two hydrogen atoms fewer and thus is not an isomer. The α-carbon atom is not a stereocenter. See also * L-Photo-Leucine Amino acids Literature * Jeremy M. Berg, John L. Tymoczko, Lubert Stryer: ''Biochemie.'' 6 Auflage, Spektrum Akademischer Verlag, Heidelberg 2007. . * Donald Voet, Judith G. Voet: ''Biochemistry.'' 3. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leucine
Leucine (symbol Leu or L) is an essential amino acid that is used in the biosynthesis of proteins. Leucine is an α-amino acid, meaning it contains an α-amino group (which is in the protonated −NH3+ form under biological conditions), an α- carboxylic acid group (which is in the deprotonated −COO− form under biological conditions), and a side chain isobutyl group, making it a non-polar aliphatic amino acid. It is essential in humans, meaning the body cannot synthesize it: it must be obtained from the diet. Human dietary sources are foods that contain protein, such as meats, dairy products, soy products, and beans and other legumes. It is encoded by the codons UUA, UUG, CUU, CUC, CUA, and CUG. Like valine and isoleucine, leucine is a branched-chain amino acid. The primary metabolic end products of leucine metabolism are acetyl-CoA and acetoacetate; consequently, it is one of the two exclusively ketogenic amino acids, with lysine being the other. It is the most import ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acids
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 lif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norleucine
Norleucine (abbreviated as Nle) is an amino acid with the formula CH3(CH2)3CH(NH2)CO2H. A systematic name for this compound is 2-aminohexanoic acid. The compound is an isomer of the more common amino acid leucine. Like most other α-amino acids, norleucine is chiral. It is a white, water-soluble solid. Occurrence Together with norvaline, norleucine is found in small amounts in some bacterial strains where its concentration can approach millimolar. Its biosynthesis has been examined. It arises via the action of 2-isopropylmalate synthase on α-ketobutyrate. The incorporation of Nle into peptides reflects the imperfect selectivity of the associated aminoacyl-tRNA synthetase. In Miller–Urey experiments probing prebiotic synthesis of amino acids, norleucine and especially norvaline are formed. Uses It is nearly isosteric with methionine, even though it does not contain sulfur. For this reason, norleucine has been used to probe the role of methionine in Amyloid-β peptide (AβP ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leucine
Leucine (symbol Leu or L) is an essential amino acid that is used in the biosynthesis of proteins. Leucine is an α-amino acid, meaning it contains an α-amino group (which is in the protonated −NH3+ form under biological conditions), an α- carboxylic acid group (which is in the deprotonated −COO− form under biological conditions), and a side chain isobutyl group, making it a non-polar aliphatic amino acid. It is essential in humans, meaning the body cannot synthesize it: it must be obtained from the diet. Human dietary sources are foods that contain protein, such as meats, dairy products, soy products, and beans and other legumes. It is encoded by the codons UUA, UUG, CUU, CUC, CUA, and CUG. Like valine and isoleucine, leucine is a branched-chain amino acid. The primary metabolic end products of leucine metabolism are acetyl-CoA and acetoacetate; consequently, it is one of the two exclusively ketogenic amino acids, with lysine being the other. It is the most import ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norleucine
Norleucine (abbreviated as Nle) is an amino acid with the formula CH3(CH2)3CH(NH2)CO2H. A systematic name for this compound is 2-aminohexanoic acid. The compound is an isomer of the more common amino acid leucine. Like most other α-amino acids, norleucine is chiral. It is a white, water-soluble solid. Occurrence Together with norvaline, norleucine is found in small amounts in some bacterial strains where its concentration can approach millimolar. Its biosynthesis has been examined. It arises via the action of 2-isopropylmalate synthase on α-ketobutyrate. The incorporation of Nle into peptides reflects the imperfect selectivity of the associated aminoacyl-tRNA synthetase. In Miller–Urey experiments probing prebiotic synthesis of amino acids, norleucine and especially norvaline are formed. Uses It is nearly isosteric with methionine, even though it does not contain sulfur. For this reason, norleucine has been used to probe the role of methionine in Amyloid-β peptide (AβP ... [...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 life ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isomer
In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Isomers do not necessarily share similar chemical or physical properties. Two main forms of isomerism are structural or constitutional isomerism, in which ''bonds'' between the atoms differ; and stereoisomerism or spatial isomerism, in which the bonds are the same but the ''relative positions'' of the atoms differ. Isomeric relationships form a hierarchy. Two chemicals might be the same constitutional isomer, but upon deeper analysis be stereoisomers of each other. Two molecules that are the same stereoisomer as each other might be in different conformational forms or be different isotopologues. The depth of analysis depends on the field of study or the chemical and physical properties of interest. The English word "isomer" () is a back-for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CAS-number
A CAS Registry Number (also referred to as CAS RN or informally CAS Number) is a unique identification number assigned by the Chemical Abstracts Service (CAS), US to every chemical substance described in the open scientific literature. It includes all substances described from 1957 through the present, plus some substances from as far back as the early 1800s. It is a chemical database that includes organic and inorganic compounds, minerals, isotopes, alloys, mixtures, and nonstructurable materials (UVCBs, substances of unknown or variable composition, complex reaction products, or biological origin). CAS RNs are generally serial numbers (with a check digit), so they do not contain any information about the structures themselves the way SMILES and InChI strings do. The registry maintained by CAS is an authoritative collection of disclosed chemical substance information. It identifies more than 182 million unique organic and inorganic substances and 68 million protein and DNA sequ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
L-Photo-Leucine
-Photo-leucine is a synthetic derivative of the -leucine amino acid that is used as its natural analog and is characterized for having photo-reactivity, which makes it suitable for observing and characterizing protein-protein interactions (PPI). When a protein containing this amino acid (A) is exposed to ultraviolet light while interacting with another protein (B), the complex formed from these two proteins (AB) remains attached and can be isolated for study. Photo-leucine, as well as another photo-reactive amino acid derived from methionine, photo-methionine, were first synthesized in 2005 by Monika Suchanek, Anna Radzikoska and Christoph Thiele from the Max Planck Institute of Molecular Cell Biology and Genetics with the objective of identifying protein to protein interaction throughout a simple western blot test that would provide high specificity. The resemblance of the photo-reactive amino acids to the natural ones allows the former ones to avoid the extensive control m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclopentane
Cyclopentane (also called C pentane) is a highly flammable alicyclic hydrocarbon with chemical formula C5H10 and CAS number 287-92-3, consisting of a ring of five carbon atoms each bonded with two hydrogen atoms above and below the plane. It occurs as a colorless liquid with a petrol-like odor. Its melting point is −94 °C and its boiling point is 49 °C. Cyclopentane is in the class of cycloalkanes, being alkanes that have one or more rings of carbon atoms. It is formed by cracking cyclohexane in the presence of alumina at a high temperature and pressure. It was first prepared in 1893 by the German chemist Johannes Wislicenus. Production, occurrence and use Cycloalkanes are formed by catalytic reforming. For example, when passed over a hot platinum surfact, 2-methylbutane converts into cyclopentane. Cyclopentane has no particular use. No commercial products are made from cyclopentane itself. As a volatile hydrocarbon it is an incidental component of some fuels and blowing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycloleucine
Cycloleucine is a non-proteinogenic amino acid. It could be classified as a cyclic derivate of norleucine, having two hydrogen atoms less. Leading structure is a cyclopentane-ring. The α-carbon atom is not a stereocenter. Cycloleucine is a non-metabolisable amino acid and is a specific and reversible inhibitor of nucleic acid methylation, and as such is widely used in biochemical experiments. In 2007, a research study performed on primary rat hepatocytes had shown that cycloleucine can lower S-Adenosyl_methionine (SAM) levels in control hepatocytes by inhibiting the conversion of 5'-methylthioadenosine to SAM through the methionine salvage pathway. Cycloleucine treatment in conjunction with higher levels of cytochrome P450 2E1 (CYP2E1) and lower SAM levels in pyrazole hepatocytes had shown an increased amount of cell apoptosis when compared to control hepatocytes. In a 2015 study on the role of N6-methyladenosine ( m6A) demethylation on adipogenesis, researchers treated porcine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
