Amino acid lysine

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. 

Some amino acids have side chains that bear- acidic or basic groups. As Table 27.3 indicates, these amino acids are characterized by three pK values. The third pK reflects the nature of the side chain. Acidic amino acids (aspartic and glutfflnic acid) have acidic side chains basic amino acids (lysine, arginine, and histidine) have basic side chains. 

PRODUCTION OF AMINO ACIDS (LYSINE AND GLUTAMIC ACID) AND INSULIN... 

Histone proteins share distinct features including a high content of basic amino acids, lysines and arginines,... 

Being amino acids, lysine and aspartic acid each has a carboxyl group, CO2 H, at one end and an amine group, NH2, at the other. Lysine has a second amine group in the side chain and aspartic acid has a second carboxyl group. 

The question of the stability of the biomolecules is a vital one. Could they really have survived the tremendous energies which would have been set free (in the form of shock waves and/or heat) on the impact of a meteorite Blank et al. (2000) developed a special technique to try and answer this question. They used an 80-mm cannon to produce the shock waves the shocked solution contained the two amino acids lysine and norvaline, which had been found in the Murchison meteorite. Small amounts of the amino acids survived the bombardment , lysine seeming to be a little more robust. In other experiments, the amino acids aminobutyric acid, proline and phenylalanine were subjected to shock waves the first of the three was most stable, the last the most reactive. The products included amino acid dimers as well as cyclic diketopiperazine. The kinetic behaviour of the amino acids differs pressure seems to have a greater effect on the reaction pathway than temperature. As had been recognized earlier, the effect of pressure would have slowed down certain decomposition reactions, such as pyrolysis and decarboxylation (Blank et al., 2001). 

Denaturation of proteins by irradiation can occur in small amounts at moderate or high doses. Some reduction in the availability of certain amino acids (lysine, methionine, etc.) has been reported in the proteins of irradiated foods. However, these effects are rather small, even at high radiation doses. 

The standard diet used in our experiments is a semipurified, cholesterol-free preparation that is composed of 25% protein, 40% sucrose, 13% coconut oil, 1% corn oil, 15% cellulose, 5% mineral mix, and 1% vitamin mix. This diet has been shown to induce an endogenous hypercholesterolemia and lead to atherosclerosis in rabbits and monkeys (4, 5). The specific question addressed by our series of investigations is whether the type of dietary protein, when all other dietary components are constant, can influence the development of hyperlipoproteinemia and atherosclerosis. More specifically, we have examined the effects of the individual amino acids, lysine and arginine, and their ratios in the diet on plasma and hepatic lipids as well as the development of arterial plaques. 

A high proportion of the positiveiy charged basic amino acids lysine and arginine within these flexible tails are frequent targets for extensive posttranslational modifications (Berger, 2002). Such modifications include the acetylation of lysine residues, the methylation of lysine and arginine residues, the ubiquitination of lysine residues, the phosphorylation of serine and threonine residues, the sumoylation of lysine residues, and the poly ADP-ribosylation of glutamic acid residues. 

For the synthesis of perfectly dendronized sohd-phase polymers (Fig. 7.4) various dendritic structures were prepared based on amide connections [6]. For example, the naturally occurring amino acid lysine was used as a building block in creating a dendritic scaffold [33]. The synthesis of symmetrical tri-branching den-drimers on aminomethyl polystyrene macrobeads was also described in literature [34]. Recently, aryl ether dendrimers were prepared on hydroxymethyl polystyrene using a Mitsunobu reaction with 3,5-bis(acetoxymethyl)phenol [35]. 

The amino acids in question are the basic amino acids lysine, arginine, and histidine, and the acidic amino acids aspartic acid and glutamic acid. The side-chain functions of these amino acids, ionized at pH 7 (see Box 4.7), act as acids or bases. In a reverse sequence, protons may be acquired or donated to regenerate the conjugate acids and conjugate bases. 

Amino acids Lysine Glutamic acid Corynebacterium glutamicum Corynebacterium glutamicum... 

Tranexamic acid (Cyklokapron, Transamin) is a synthetic derivative of the amino acid lysine. It exerts its antifibrinolytic effect through the reversible blockade of lysine binding sites on plasminogen molecules. 

Based on the properties of the side chains, the 20 amino acids can be put into six general classes. The first class contains amino acids whose side chains are aliphatic, and is usually considered to include glycine, alanine, valine, leucine, and isoleucine. The second class is composed of the amino acids with polar, nonionic side chains, and includes serine, threonine, cysteine, and methionine. The cyclic amino acid proline (actually, an imino acid) constitutes a third class by itself. The fourth class contains amino acids with aromatic side chains tyrosine, phenylalanine, and tryptophan. The fifth class has basic groups on the side chains and is made up of the three amino acids lysine, arginine, and histidine. The sixth class is composed of the acidic amino acids and their amides aspartate and asparagine, and glutamate and glutamine. 

The essential amino acid lysine (2,5-diaminohexanoic acid) can be degraded via two pathways, viz. the so-called saccharopine pathway and the pipecolic acid (PA) pathway. Both pathways merge at the level of a-aminoadipic acid semialdehyde (AASA). It is generally accepted that the saccharopine pathway constitutes the major breakdown pathway. However, the PA pathway has attracted much attention since the discovery of the association between the presence of elevated PA levels and Zellweger syndrome almost 40 years ago. Mainly because the analysis of amino acids was the primary biochemical approach for studying presumed inborn errors of metabolism, PA in Zellweger syndrome was discovered even before it was realized that this disorder was based on a defect of peroxisomal functions. 

Caprolactam is used primarily in the manufacture of synthetic fibres and resins (especially nylon 6), bristles, film, coatings synthetic leather, plasticizers and paint vehicles as a cross-linking agent for polyurethanes and in the synthesis of the amino acid lysine (Lewis, 1993). 

Cystinuria is a disorder of the proximal tubule s reabsorption of filtered cystine and dibasic amino acids (lysine, ornithine, arginine). 

The amino acid lysine is shown here. What functional group must be removed in order to produce cadaverine, as shown in Figure 12.16 ... 

Cold cereal is often fortified with all sorts of vitamins and minerals but is deficient in the amino acid lysine. How might this deficiency be compensated for in a breakfast meal ... 

The 4-carbon aspartate molecule is the starting point for synthesis of pyrimidines and of the amino acids lysine, methionine, threonine, isoleucine, and... 

Carboxypeptidase A catalyzes the hydrolysis of carboxyl-terminal acidic or neutral amino acids however, the rate of hydrolysis depends on the structure of the side chain R. Amino acids with nonpolar aryl or alkyl side chains are cleaved more rapidly. Carboxypeptidase B is specific for the hydrolysis of basic COOH-terminal amino acids (lysine and arginine). Neither peptidase functions if proline occupies the COOH-terminal position or is the next to last amino acid. 

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