Amino acids Chemical

In some protein sources storage protein may be isolated from non-storage protein, or acid-precipitated proteins isolated from whey proteins. In the preparation of classical protein isolates by solubilization and acid precipitation, the amino acid make-up of the isolate differs from that of the extract. Consequently, consideration must be given to the amino acids chemically present in a refined protein. 

Keil, R. G., and D. L. Kirchman. 1993. Dissolved combined amino acids Chemical form and utilization by marine bacteria. Limnology and Oceanography 38 1256—1270. 

Bittner, S. (2006). When quinones meet amino acids Chemical, physical and biological consequences. Amino Acids 30, 205-224. 

Table I. Biological Availability in Rats of the Amino Acids Chemically Modified During Food Processing...

Nutritional and Physiological Effects of Alkali-Treated Proteins. The first effect of the alkaline treatment of food proteins is a reduction in the nutritive value of the protein due to the decrease in (a) the availability of the essential amino acids chemically modified (cystine, lysine, isoleucine) and in (b) the digestibility of the protein because of the presence of cross-links (lysinoalanine, lanthionine, and ornithinoalanine) and of unnatural amino acids (ornithine, alloisoleucine, / -aminoalanine, and D-amino acids). The racemization reaction occurring during alkaline treatments has an effect on the nitrogen digestibility and the use of the amino acids involved. 

Noncoded amino-acids Chemical synthesis is not limited to coded amino acids and potentially allows the generation of an infinite variety of nonnatural analogs. 

Amino Acid Chemical Formula Isotopic Molar Mass(Da) Chemical Molar Mass (Da) Isoelectric Point (pH) Three- Letter Code Single- Letter Code Residue Mass (Aaa/amu (or Daltons)... 

There are two main routes for the production of D-amino acids chemical synthesis and enzymatic catalysis. As regards conventional chemical synthesis, unless asymmetrical starting compounds or catalysts are used, a mixture of the D- and L-stereoisomers is obtained in equal proportions. The racemic mixture is therefore optically inactive and the stereoisomers must be separated. The separation of the enantiomers by classical crystallization of diastereomeric salts is the most costly production step and in any case this method can only yield 50% of the desired enantiomer [3]. Enzymatic synthesis can solve the above problems, providing optical purity of the D-amino acid and a 100% yield, as well as mild, environment-friendly reaction conditions. 

Rehms, A. A., and Callis, P. R. (1993). Two-photon fluorescence excitation spectra of aromatic amino acids. Chemical Physics Letters 208 276-282. 

Poulet, S. A., and Martin-Jezequel, V. (1983). Relationships between dissolved free amino acids, chemical composition and growth of the marine diatom Chaetoceros debile. Mar. Biol. 77, 93-100. 

Amino Acids, Chemical Properties of Click Peptides, Design and Application of Peptide Combinatorial Libraries Solid-Phase Synthesis of Biomolecules... 

Chemical Modification of Proteins Amino Acids, Chemical Properties of Enzyme Catalysis, Chemical Strategies for Proteins, In Vivo Chemical Modifications of Peptides, Chemistry of... 

Poly(amino acid) Chemical yield (%) Optical yield (%)... 

Arginine, 2D biosynthesis, 435 catabolism, 431 134 chemical structure, 20 plasma concentration, 465 Argininosuccinate lyase, 439 Acgininosuccinate synthase, 439 Aromatic amino acids, chemical structure, 19 Arsenate, 840 Artenosclcrosis, 357 Arteriovenous differences, 19 199 Artery, physiology, 359 Ascoitale... 

Nearly every protein in a cell is chemically modified after its synthesis on a ribosome. Such modifications, which may alter the activity, life span, or cellular location of proteins, entail the linkage of a chemical group to the free -NH2 or -COOH group at either end of a protein or to a reactive side-chain group in an internal residue. Although cells use the 20 amino acids shown in Figure 2-13 to synthesize proteins, analysis of cellular proteins reveals that they contain upward of 100 different amino acids. Chemical modifications after synthesis account for this difference. 

Hsu et ah [6] developed an ass for the high-affinity Mn-binding site in PS II. In this assay /xM concentrations of Mn competitively inhibit 1,5-diphenylcarbazide (DPC) supported 2,6-dichlorophenol indophenol (DCIP) electron transport. Using this assay on PS II membranes modified with proteases and amino acid chemical modifiers, we have identified four components in the high-affinity Mn-binding site, corresponding to the four Mn required for functional Oj evolution. 

Amino Acids Chemical building blocks of proteins that contain a nitrogen-containing amino group (-NHg), a carboxylic acid (-GOOH), and a functional group that varies between amino acids and determines their chemical properties. 

Four main processes are distinguished in the production of amino acids chemical synthesis, isolation from protein hydrolysates, enzymatic and microbiological methods of production, which is currently the most important. The following sections will further elucidate the important... 

The initial step in the metabolism of amino acids is the removal of the amino group (-NH ), leaving the carbon skeleton of the amino acid. Chemically, these carbon skeletons are ketoacids (more correctly, they are oxo-acids). A ketoacid has a —C=0 group in place of the HC-NH group of an amino acid the metabolism of ketoacids is discussed in section 9.3.2. 

The name given to two amino acids chemically linked together, it is a final stage in the digestion and absorption of proteins or an initial step in protein synthesis. 

Ten to one hundred amino acids chemically joined by a peptide bond are termed polypeptides. In the body, polypeptides occur as a result of protein digestion or protein synthesis. 

These are three amino acids chemically joined together by peptide bonds. They may be a step in the synthesis of new protein, or a step in the breakdown of dietary protein. 

Ibrahem, L, Rios, R., Vesely, J., Zhao, G.-L., Cordova, A. (2007). Organocatalytic asymmetric 5-hydroxyisoxazohdine synthesis a highly enantioselective ronte to p-amino acids. Chemical Communications, 849—851. 

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