Amino acids from protein

One of the most useful applications of chiral derivatization chromatography is the quantification of free amino acid enantiomers. Using this indirect method, it is possible to quantify very small amounts of enantiomeric amino acids in parallel and in highly complex natural matrices. While direct determination of free amino acids is in itself not trivial, direct methods often fail completely when the enantiomeric ratio of amino acid from protein hydrolysis must be monitored in complex matrices. 

Gluconeogenesis Formation of glucose from precursors other than carbohydrates (especially by the liver and kidney) using amino acids from proteins, glycerol from fats, or lactate produced by muscle during anaerobic glycolysis. 

Demmelmair, H. and Schmidt, H. L. (1993) Precise 813C determination in the range of natural abundance on amino acids from protein hydrolysates by gas chromatography isotope ratio mass spectrometry. Isotopenpraxis 29, 237 250. 

Tyrosine (Tyr or Y) (4-hydroxyphenylalanine ((5)-2-amino-3-(4-hydroxyphenyl)-propanoic acid)) is a polar, neutral, aromatic amino acid with the formula H00CCH(NH2)CH2C6H50H and is the precursor of thyroxin, dopamine, norepinephrine (noradrenaline), epinephrine (adrenaline), and the pigment melanin. Being the precursor amino acid for the thyroid gland hormone thyroxin, a defect in this may result in hypothyroidism. Tyr is extremely soluble in water, a property that has proven useful in isolating this amino acid from protein hydrolysates. The occurrence of tyrosine- 0-sulfate as a constituent of human urine and fibrinogen has been reported. ... 

Neurotransmitter Production. Neurotransmitters are relatively simple chemicals, and our bodies make most of the ones that we use. The nerve cell receives precursor substances such as amino acids from proteins in the diet and chemically processes these precursors to form neurotransmitter chemicals. The neurotransmitter is then stored in small sacs inside the neuron called storage vesicles. These storage vesicles reside inside the axon terminals. 

Since much less glucose is required by the brain, the rate of gluconeogenesis falls and hence the rate of protein degradation falls. In the obese, the energy provided from the oxidation of glncose that has been provided by amino acids from protein degradation is as little as 5% of the total (it is much higher in the lean see below). 

Simpson, M.V. (1953). The release of labeled amino acids from proteins in liver slices. J. Biol. Chem. 201, 143-154. 

In chromatographic techniques, qualitative identitication of organic binders requires quantitication of species obtained from the original polymeric materials amino acids from proteins, fatty acids from drying oils, or monosaccharides in plant gums. 

The availability of amino acids from protein may be affected by the refinement of the types of protein molecules. 

Many aminopeptidases are zinc metalloenzymes.521 They catalyze the specific hydrolysis of N-terminal amino acids from proteins and peptides, and usually have a broad substrate specificity. The zinc aminopeptidases from mammalian sources are oligomeric, with molecular weights greater than 200 000, and have two moles zinc per mole subunit. Enzymes from microbial sources are usually monomeric (40 000 molecular weight) with one or two moles Zn11. 

Concentration Edible table salt production from seawater Salts of organic acids from exhausted fermentation media Amino acids from protein hydrolysates... 

New method for separation of the basic amino acids from protein hydroly-sates. Proc. Soc. Exptl. Biol. Med., 51, 252 (1942). 

Aminopeptidase, Leucine Hydrolysis of /V-terminal amino acid, which is preferably leucine, but may be other amino acids, from proteins and oligopeptides, yielding free amino acids and oligopeptides of lower molecular weight. 

Proteins are made of amino acids arranged in chains joined by bonds that distinguish them as peptides. Proteins are essential parts of all plants and animals, participating in every process of cell structure and function. Some proteins are important for cell communication, immune responses, and life cycle. Proteins are also necessary in your diet, because the body cannot synthesize all the amino acids required for proteins to build cells, so you must obtain essential amino acids from proteins in your foods. Among superfruits particularly excellent as sources of amino acids and proteins are fig, goji, kiwifruit, seaberry, and guava. 

Baptist, N. G., and W. Robson The Salting out of Amino Acids from Protein... 

Hill, E. M., and W. Robson The Salting out of Amino Acids from Protein Hydrolysates. I. The Isolation of Tyirosine, Leucine and Methionine. Biochem. J. 28, 1008 (1934). 

The two purposes of separation of amino-acid and peptide mixtures are either at the preparative level, to isolate one or more individual components from the mixture for further study or at the analytical level, to identify and to determine the relative amounts of some or all of the components. Most of the routine studies, conducted daily to determine the amino-acid content of clinical and botanical samples in hundreds of laboratories around the world, are at the analytical level. However, many of the research studies are at the preparative level an example of this is the identification of crosslinking amino acids from proteins, through their isolation from protein hydrolysates, from physiological specimens for medical investigations, or purely to gain new knowledge. 

Carboxypeptidases which remove the C-terminal amino acids from proteins. 

Further aspects distinguishing poly(amino acids) from proteins are the following ... 

Polarimetry Total amino acids in proteins or hydrolysates, or pure amino acids Cumbersome separation of each amino acid from protein hydrolysates 15-19... 

Biochemical pathways may be described as catabolic, anabolic (biosynthetic), amphibolic or anaplerotic. The principal function of a catabolic sequence is to degrade (usually by an oxidative process) simple organic molecules derived from the breakdown of polymers (e.g. amino acids from proteins) and retain some of the free energy released in a biologically useful form. Anabolic pathways consume energy and synthesize (usually by a reductive process) the simple molecules which are assembled into proteins, nucleic acids, carbohydrate polymers and lipids. Amphibolic pathways, such as the tricarboxylic acid cycle, have both catabolic and anabolic properties. They are central metabolic pathways which furnish, from catabolic sequences, the intermediates which form the substrates of anabolic processes. The... 

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