Isoleucine supplemental

Yeast strains are grown on either standard yeast extract, peptone, glucose media (YPD) (1% (w/v) yeast extract, 2% (w/v) bactopeptone, and 2% (w/v) glucose) and supplemented with the appropriate antibiotic, or in synthetic complete media (SCD media) (0.17% (w/v) yeast nitrogen base. 0.5% (w/v) ammonium sulphate, 2% (w/v) glucose, and supplemented with 20 mg/1 arginine, 100 mg/1 aspartic acid, 100 mg/1 glutamine, 30 mg/1 isoleucine, 30 mg/llysine, 20 mg/1 methionine, 50 mg/1 phenylalanine, 400 mg/lserine, 200 mg/1 threonine, 30 mg/1 tyrosine, and 150 mg/1 valine. When needed, the media was also supplemented with 20 mg/1 adenine, 10 mg/1 leucine, 60 mg/1 histidine, 60 mg/1 tryptophan, and 20 mg/1 uracil). 

Special diet low in isoleucine, valine, methionine, threonine. Carnitine supplementation. Liver transplantation may be beneficial. 

In a rare autosomal recessive condition (discovered in 1954) the urine and perspiration has a maple syrup odor/ High concentrations of the branched-chain 2-oxoacids formed by transamination of valine, leucine, and isoleucine are present, and the odor arises from decomposition products of these acids. The branched-chain amino acids as well as the related alcohols also accumulate in the blood and are found in the urine. The biochemical defect lies in the enzyme catalyzing oxidative decarboxylation of the oxoacids, as is indicated in Fig. 24-18. Insertions, deletions, and substitutions may be present in any of the subunits (Figs. 15-14,15-15). The disease which may affect one person in 200,000, is usually fatal in early childhood if untreated. Children suffer seizures, mental retardation, and coma. They may survive on a low-protein (gelatin) diet supplemented with essential amino acids, but treatment is difficult and a sudden relapse is apt to prove fatal. Some patients respond to administration of thiamin at 20 times the normal daily requirement. The branched-chain oxoacid dehydrogenase from some of these children shows a reduced affinity for the essential coenzyme thiamin diphosphate.d... 

Spectra of many of the common amino acids not yet discussed are shown in Fig. 2, kindly made available by Sussman and Gratzer (1962). The data of this figure are usefully supplemented by the earlier but less extensive (2000-2300 A) observations of Saidel et al. (1952). In addition to some duplication of the amino acids of Fig. 2, Saidel et al. showed spectra of cysteic acid, hydroxyproline, asparagine, valine, isoleucine, and glycine. The monoamino, monocarboxylic amino acids, including the hydroxyamino acids and the imino acids, are seen to have very similar spectra at wave-... 

The translational activity of various unsaturated analogs of L-isoleucine was evaluated using an Escherichia coli strain auxotrophic for isoleucine. It was observed that the alkene [2-amino-3-methyl-4-pentenoic acid (2)] and alkyne [2-amino-3-methyl-4-pentynoic acid (3)] derivatives of L-isoleucine can support protein synthesis at levels approximately 50% of that observed in cultures supplemented with isoleucine. However, no incorporation of the ocC or /JC methylated derivatives could be detected. In order to examine the stereoselectivity of incorporation, the (2S, 3S) and (2S, 3R) diastereomers of 2 and 3 were prepared. The extents of isoleucine substitution in vivo were 80% and 70% for (2S, 3S)-2 and (2S, 3S)-3, respectively, under the conditions examined in this study. 

Among the 20 proteinogenic amino acids, only L-isoleucine and L-threonine carry a symmetry center in their side chain and only (2S, 3S)-isoleucine and (2S, 3R)-threonine are found in proteins. When L-isoleucine was replaced in the culture medium by L-alloisoleucine, the (2S, 3R)-1 diastereomer of isoleucine, the cell growth slowed dramatically, without evidence of cell lysis. As western blotting did not show detectable DHFR expression in such cultures, we conclude that (2 S, 3R)-1 is incorporated into protein slowly if at all under our experimental conditions (Figure 3B, lane 5). However, small amounts of DHFR could be isolated from such culture (ca. 8% of the level of expression obtained in media supplemented with L-isoleucine, see Table 1). DHFR synthesis was not due to leaky expression before induction, as uninduced cells did not produce DHFR in media supplemented with L-isoleucine (Figure 3B, lane 3). Instead it appears that... 

A fraction of 3 enriched with the (2S, 3S) isomer (diastereomeric ratio 8.6/1.4) was tested. This fraction did not support growth but instead caused cell lysis (Table 1), confirming the toxicity of the analog previously reported.19 When DHFR was expressed in media supplemented with (2S, 3S)-3 (Figure 2B lane 6) approximately 70% of the isoleucine was replaced by the analog (Table 1). When a fraction of 3 enriched in the (2S, 3R) diastereomer (diastereomeric ratio 8.3/1.7) was used the amount of DHFR recovered was too low to allow determination of the extent of incorporation. 

Some products sold in health food stores feature the presence of the branched-chain amino acids isoleucine, leucine, and valine. These are essential amino acids in the sense that the body cannot synthesize them. Under normal circumstances, a diet with adequate protein intake provides enough of all the essential amino acids. Athletes involved in intensive training want to prevent muscle loss and to increase muscle mass. As a result, they take protein supplements and pay particular attention to branched-chain amino acids. (These three amino acids are by no means the only essential ones, but they are mentioned specifically here.)... 

Maple syrup urine disease is a rare genetic disorder affecting the metabohsm of leucine, isoleucine and valine. Accumulation of these branched-chain amino acids results in severe neurological damage and death. The aim of dietary management is to prevent the accumulation of these amino acids, by the use of a low-protein diet and leucine-, isoleucine-and vahne-free amino acid preparations. Natural protein supplies the necessary leucine, isoleucine and valine, based on a leucine exchange system with additional isoleucine and/ or valine available as single amino acid supplements. 

The leucine-, isoleucine- and vafrne-free drink mix MSUD Aid III is suitable for infants, children, adolescents and adults but, unlike other proprietary preparations suitable for the management of Maple syrup urine disease, it is carbohydrate, fat, vitamin and mineral free, which need to be added to the diet. This may allow more appropriate age-specific supplementation including iodine. 

MacDonald (24) found that labeled aspergillic acid (1) is produced by Asp. flavus grown on a medium supplemented with radioactive leucine and isoleucine. Hydrolysis of the labeled metabolite shows that it is biosynthesized from one molecule each of leucine and isoleucine. The same result is also recognized in hydroxy aspergillic acid (4). 

Supplement Valine and isoleucine (if plasma concentrations are below target range), thiamine ... 

Calculate valine and isoleucine intake provided by the infant formula/breast milk. Determine the amount of supplemental valine and isoleucine to add to meet recommended intakes (Table 16.1). The recommended concentration of valine and isoleucine supplanents is 10 mg/mL (1 g amino acid in 100 mL water). 

Recalculate the amount of supplemental isoleucine and valine needed to meet your intake goals. 

Restrict Propiogenic amino acids (valine, isoleucine, methionine, threonine) Supplement L-camitine Trial of intramuscular hydroxocobalamin in MMA ... 

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