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The Amino Acids

X-alanine, 2-aminopropanoic acid, C3H7NO2, CH3.CH(NH2)C00H. M.p. 297X. One of the amino-acids obtained by the hydrolysis of proteins. [Pg.18]

The amino-acids are colourless, crystalline substances which melt with decomposition. They are mostly soluble in water and insoluble in alcohol. [Pg.29]

As constituents of proteins the amino-acids are important constituents of the food of animals. Certain amino-acids can be made in the body from ammonia and non-nitrogenous sources others can be made from other amino-acids, e.g. tyrosine from phenylalanine and cystine from methionine, but many are essential ingredients of the diet. The list of essential amino-acids depends partly on the species. See also peptides and proteins. [Pg.29]

H2N (CH2]5 NH2. a syrupy fuming liquid, b.p. 178-180 - C. Soluble in water and alcohol. Cadaverine is one of the ptomaines and is found, associated with pulrescine, in putrefying tissues, being formed by bacterial action from the amino-acid lysine. It is found in the urine in some cases of the congenital disease cystinuria. The free base is poisonous, but its salts are not. [Pg.74]

M.p. 246-250°C (decomp.). A dipeptide present in mammalian muscle. Like anserine it contains the amino-acid -alanine which is not found in proteins. [Pg.84]

C3H7NO3, CH20H-CHNH2-C02H. Colourless crystals m.p. 228 C (decomp.). It is one of the amino-acids present in small quantities among the hydrolysis products of proteins. [Pg.356]

First, it is possible to excite a chromophore corresponding to the active site, and detennine which modes interact with it. Second, by using UV excitation, the amino acids with phenyl rings (tryptophan and tyrosine, and a small contribution from phenylalanine) can be selectively excited [4], The frequency shifts in the resonance Raman spectrum associated with them provide infomiation on their enviromnent. [Pg.1171]

Most reactions in cells are carried out by enzymes [1], In many instances the rates of enzyme-catalysed reactions are enhanced by a factor of a million. A significantly large fraction of all known enzymes are proteins which are made from twenty naturally occurring amino acids. The amino acids are linked by peptide bonds to fonn polypeptide chains. The primary sequence of a protein specifies the linear order in which the amino acids are linked. To carry out the catalytic activity the linear sequence has to fold to a well defined tliree-dimensional (3D) stmcture. In cells only a relatively small fraction of proteins require assistance from chaperones (helper proteins) [2]. Even in the complicated cellular environment most proteins fold spontaneously upon synthesis. The detennination of the 3D folded stmcture from the one-dimensional primary sequence is the most popular protein folding problem. [Pg.2642]

Abstract. A smooth empirical potential is constructed for use in off-lattice protein folding studies. Our potential is a function of the amino acid labels and of the distances between the Ca atoms of a protein. The potential is a sum of smooth surface potential terms that model solvent interactions and of pair potentials that are functions of a distance, with a smooth cutoff at 12 Angstrom. Techniques include the use of a fully automatic and reliable estimator for smooth densities, of cluster analysis to group together amino acid pairs with similar distance distributions, and of quadratic progrmnming to find appropriate weights with which the various terms enter the total potential. For nine small test proteins, the new potential has local minima within 1.3-4.7A of the PDB geometry, with one exception that has an error of S.SA. [Pg.212]

The protein folding problem is the task of understanding and predicting how the information coded in the amino acid sequence of proteins at the time of their formation translates into the 3-dimensional structure of the biologically active protein. A thorough recent survey of the problems involved from a mathematical point of view is given by Neumaier [22]. [Pg.212]

The forces in a protein molecule are modeled by the gradient of the potential energy V(s, x) in dependence on a vector s encoding the amino acid sequence of the molecule and a vector x containing the Cartesian coordinates of all essential atoms of a molecule. In an equilibrium state x, the forces (s, x) vanish, so x is stationary and for stability reasons we must have a local minimizer. The most stable equilibrium state of a molecule is usually the... [Pg.212]

The class of a pair of amino acids in positions i, A of a sequence s depends on the labels Si and s, of the amino acids and the residue distance i — k, and is specified through a suitably constructed class table, and... [Pg.215]

Fig. 3. Some representative pair potentials Uy(r), sealed to move their interesting range to [0,5]. The numbers above each potential denote the class label 7 and the iiinnber of data points available for the fit. (For example, elass 63 gives distanee 3 potentials for the amino acid pairs Lys-Asp, Arg-Lys and Glu-Tyr.) The spectrum below each potential consists of 50 lines pieked uniformly from the data. Fig. 3. Some representative pair potentials Uy(r), sealed to move their interesting range to [0,5]. The numbers above each potential denote the class label 7 and the iiinnber of data points available for the fit. (For example, elass 63 gives distanee 3 potentials for the amino acid pairs Lys-Asp, Arg-Lys and Glu-Tyr.) The spectrum below each potential consists of 50 lines pieked uniformly from the data.
Figure 2-1 S3. The ViewerLite shows an elaborate depiction of hemoglobin on the right-hand side, with the amino acids in a cascade window on the left. Figure 2-1 S3. The ViewerLite shows an elaborate depiction of hemoglobin on the right-hand side, with the amino acids in a cascade window on the left.
Figure 7-14. All-atom and united-atom representation of the amino acid isoleucine. In this example, 13 atoms, which are able to form explicit non-bonding interactions, are reduced to only four pseudo-atoms,... Figure 7-14. All-atom and united-atom representation of the amino acid isoleucine. In this example, 13 atoms, which are able to form explicit non-bonding interactions, are reduced to only four pseudo-atoms,...
It is important to notice that the united-atom simplification cannot be applied to functional hydrogens which are involved in the formation of a hydrogen hond or a salt bridge. This would destroy interactions important for the structural integrity of the protein. Removing the hydrogen at the u-carbon of the peptide backbone is also dangerous, because it prevents racemization of the amino acid. [Pg.363]

The comparison of both data sources qualitatively shows a similar picture. Regions of high mobflity are located especially between the secondary structure elements, which are marked on the abscissa of the plot in Figure 7-17. Please remember that the fluctuations plotted in this example also include the amino acid side chains, not only the protein backbone. This is the reason why the side chains of large and flexible amino acids like lysine or arginine can increase the fluctuations dramatically, although the corresponding backbone remains almost immobile. In these cases, it is useful to analyze the fluctuations of the protein backbone and side chains individually. [Pg.373]


See other pages where The Amino Acids is mentioned: [Pg.28]    [Pg.29]    [Pg.188]    [Pg.193]    [Pg.233]    [Pg.238]    [Pg.333]    [Pg.416]    [Pg.434]    [Pg.80]    [Pg.2642]    [Pg.2815]    [Pg.2817]    [Pg.46]    [Pg.216]    [Pg.339]    [Pg.371]    [Pg.372]    [Pg.122]    [Pg.187]    [Pg.187]    [Pg.344]    [Pg.476]    [Pg.525]    [Pg.525]    [Pg.528]    [Pg.529]    [Pg.532]    [Pg.536]    [Pg.536]    [Pg.538]    [Pg.539]    [Pg.540]    [Pg.541]   


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A-2 Studies on the pyrolysis of amino acids

Acidity of the Amino Acids

Alanine and the Branched-Chain Amino Acids

Amino Acid Oxidation and the Release of Ammonia

Amino Acid Sequence in the Phenylalanyl Chains

Amino Acid Sequence of the Isoforms

Amino Acids Are Required in the Diet for Good Nutrition

Amino Acids Linked with the Citric Acid Cycle

Amino Acids Serve as the Precursors for Compounds Other Than Proteins

Amino Acids and the Henderson-Hasselbalch Equation Isoelectric Points

Amino Acids and the Peptide Bond

Amino Acids in the Visual System

Amino Acids on the Chromatogram

Amino acid The building block of proteins

Amino acid transport into the mammary cell

Amino acids by the Strecker reaction

Amino acids in the genetic code

Amino acids in the life sciences

Aromatic Amino Acids Absorb Light in the Near-Ultraviolet

Benefits and Limitations of the Amino Acid Pro-drug

Biosynthesis of the Aromatic Amino Acids

Biosynthesis of the essential amino acids

Biosynthesis of the non-essential amino acids

Catabolism of Amino Acids The Carbon Chains

Catalytic Properties of the Aliphatic Amino Acid Hydroxylases

Determining the sequence of amino acids

Enzymes That Catalyze Amino Acid Biosynthesis Are Regulated at the Level of Transcription Initiation

Evidence on the Pathways of Aromatic Amino Acid Biosynthesis

Fate of the Liberated Amino Acids

Foetal umbilical venous and arterial plasma amino acid concentrations are depending on the protein level of gestation diets fed to gilts

Gas Phase Acidities and Electron Affinities of the Amino Acids

Guidelines for Obtaining the Amino Acid Sequence from a Mass Spectrum

Humans and Rodents Synthesize Less Than Half of the Amino Acids They Need for Protein Synthesis

Hydroxylation of the aromatic amino acids

Introduction the main conformational features of amino acids and peptides

Is a Common Precursor of the Aromatic Amino Acid Family

Natural Products Probably Related to the Aromatic Amino Acids

Nucleophilic Reactions and the pi of Amino Acid Side Chains

Of the Amino Acids

Preparations Used in the Study of Amino Acid Transport

Problems in the Transport of Amino Acids During Neurotransmission

Racemization of the Amino Acid Substrate

Specific Amino Acids at the Active-Site Involved in Catalysis and Substrate Binding

Specific Application in the Synthesis of Non-natural Amino Acids

Structure and Stereochemistry of the a-Amino Acids

The Acid-Base Properties of Amino Acids

The Aliphatic Branched-Chain Amino Acids

The Amino Acid Composition of Some

The Amino Acid Requirements of Man

The Amino Acid Side Chains

The Amino Acids in Proteins

The Amino-Acid Sequence of Clupeine YI

The Amino-Acid Sequence of Clupeine YII

The Arrangement of Amino Acids

The Building Blocks of Proteins Amino Acids, Peptides, and Polypeptides

The Configuration of Amino Acids

The Glutamate Family of Amino Acids and Nitrogen Fixation

The Level of Transmitter Amino Acids in Brain

The Metabolism of Nitrogen and Amino Acids

The Nature and Properties Desired of Protected Amino Acids

The Nomenclature of Amino Acids

The Optically Active Amino Acids

The Role of Tetrahydrobiopterin in Aromatic Amino Acid Hydroxylases

The Sulfur Amino Acids

The Synthesis of Amino Acids

The Synthesis of Glycosyl Amino Acids

The Use of Enzymes for Amino Acid Sequencing

The amino acid analyser

The amino acid example again

The amino acids as buffers

The aromatic amino acids

The essential amino acids

The genetic code specifies 20 different amino acid side chains

The geological and extra-terrestrial distribution of amino acids

The incorporation of amino acids

The metabolism of amino acids

The pattern of amino acids in seawater

The role of amino acids in protein biosynthesis

Transfer RNA Carries Amino Acids to the Template for Protein Synthesis

Transfer RNAs Order Activated Amino Acids on the mRNA Template

What Are the Acid-Base Properties of Amino Acids

What are the best scales of amino acid attributes

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