Amino acid arginine

One step in the urea cycle for ridding the body of ammonia is the conversion of argininosuccinate to the amino acid arginine plus fumarate. Propose a mechanism for the reaction, and show the structure of arginine. 

Partial hydrolysis of a peptide can be carried out either chemically with aqueous acid or enzymatically. Acidic hydrolysis is unselective and leads to a more or less random mixture of small fragments, but enzymatic hydrolysis is quite specific. The enzyme trypsin, for instance, catalyzes hydrolysis of peptides only at the carboxyl side of the basic amino acids arginine and lysine chymotrypsin cleaves only at the carboxyl side of the aryl-substituted amino acids phenylalanine, tyrosine, and tryptophan. 

The non-metals carbon, nitrogen and oxygen are all essential for man, as is element number 9, fluorine. Some of the biological effects of the important intracellular messenger, nitric oxide, NO, which is derived from the amino acid arginine, are illustrated in... 

Figure 5.14. NO formation from arginine. The enzyme NO synthase catalyses the formation of NO from the amino acid arginine.

Sowden et al. [4] also did detailed amino acid and amino sugar analyses of the soils from the different dimatic regions. The following amino acids were determined acidic amino acids aspartic and glutamic acids basic amino acids arginine, histidine, lysine and ornithine neutral amino adds, phenylalanine, tyrosine, glycine, alanine, valine, leudne, isoleudne, serine, threonine, proline and hydroxyproline ... 

Nitric oxide is widely distributed and at least three isoenzymes of nitric oxide synthase (NOS) have been described iNOS (inducible), eNOS (endothelial) and nNOS (neuronal). The substrate for NOS is the amino acid arginine ... 

As shown in Figure 5.5, nitric oxide is synthesized from the amino acid arginine under the influence of nitric oxide synthase (NOS). This enzyme exists in several tissues as either a constitutive or inducible protein (iNOS). 

Theoretical calculations predict that, compared to other amino acids, arginine may dimerize and trimeiize in the zwitterionic state. Soft-sampling ESI of the racemate of arginine, with one of the enantiomer isotopically labeled, reveals the formation of stable trimers with NOj" present as counterion. No preference for... 

The next question is, where the protons go to in the active site during the catalytic cycle. For the base, there are too many possibilities to be certain. Groups near to the dinuclear cluster that can accept or exchange protons include the side chains of the amino acids arginine and histidine, thiolate ligands to the cluster, and peptide NH groups. 

More than a decade ago, it became clear that the human body makes NO. It is made in the brain, in the muscle cells which exist in the interior of the blood vessels, by macrophages (white cells that form an important part of the immune system), by the corpus cavemosum of the penis, and perhaps elsewhere. NO plays an important role in each of these tissues. The source of the atoms for the synthesis of NO is the common amino acid arginine (chapter 9). Under the influence of an enzyme termed NO synthase, arginine is converted to NO (and other products). The lifetime of NO in the tissues is quite short, a few seconds, but it lasts long enough to be effective. 

C - G - G codes for the amino acid arginine. The third set of bases,... 

Cleavage of fumarate from argininosuc-cinate leads to the proteinogenic amino acid arginine, which is synthesized in this way in animal metabolism. 

The disease is characterized by excessive excretion of cystine and the dibasic amino acids arginine, lysine, and ornithine by the kidneys that may lead to precipitation of some of these compounds in the form of kidney stones. 

The answer is D. The patient s symptoms are consistent with a kidney stone, which is confirmed by the radiographic finding. The etiology of the stone is indicated by the urinalysis data, which suggest cystinuria. The cells of this patient s renal proximal tubules would be deficient in a transporter responsible for the reabsorptive uptake of cystine and the basic amino acids, arginine, lysine, and ornithine. Failure of the tubules to reabsorb these amino acids from the ultrafiltrate causes them to be excreted at high concentration in the urine. 

Nitric oxide (NO) and carbon monoxide are atypical neurotransmitters. They are not stored in synaptic vesicles, are not released in by exocytosis, and do not act at postsynaptic membrane receptor proteins. NO is generated in a single step from the amino acid arginine through the action of the NO synthase (NOS). The form of NOS initially purified was designated nNOS (neuronal NOS), the macrophage form is termed inducible NOS (iNOS), and the endothelial from is called eNOS. 

In the PI position, as expected, a basic group is preferred. Interestingly, of the two naturally occuring basic amino acids, arginine is preferred over lysine. This is seen in both the BPTI mutants as well as the... 

Found in the chromatin of all eukaryotic cells, histones have molecular weights between 11,000 and 21,000 and are very rich in the basic amino acids arginine and lysine (together these make up about one-fourth of the amino acid residues). All eukaryotic cells have five major classes of histones, differing in molecular weight and amino acid composition (Table 24-3). The H3 histones are nearly identical in amino acid sequence in all eukaryotes, as are the H4 histones, suggesting strict conservation of their functions. For example, only 2 of 102 amino acid residues differ between the H4 histone molecules of peas and cows, and only 8 differ between the H4 histones of humans and yeast. Histones HI, H2A, and H2B show less sequence similarity among eukaryotic species. 

Classification of amino acids. Arginine and histidine are essential under some conditions. 

Trypsin. A proteolytic enzyme that cleaves peptide chains next to the basic amino acids arginine and lysine. 

A non-parametric classification technique was recently proposed by Schatzki and Vandercook (172) to evaluate orange juice. The system considers the total sugars, reactive phenols, total amino acids, arginine and y -aminobutyric acid. With the para-... 

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