Amino acids limiting

Limit dextrins Limiting amino acid Limiting current... 

Formation of an amide bond (peptide bond) will take place if an amine and not an alcohol attacks the acyl enzyme. If an amino acid (acid protected) is used, reactions can be continued to form oligo peptides. If an ester is used the process will be a kinetically controlled aminolysis. If an amino acid (amino protected) is used it will be reversed hydrolysis and if it is a protected amide or peptide it will be transpeptidation. Both of the latter methods are thermodynamically controlled. However, synthesis of peptides using biocatalytic methods (esterase, lipase or protease) is only of limited importance for two reasons. Synthesis by either of the above mentioned biocatalytic methods will take place in low water media and low solubility of peptides with more than 2-3 amino acids limits their value. Secondly, there are well developed non-biocatalytic methods for peptide synthesis. For small quantities the automated Merrifield method works well. 

At which position(s) are amino acids limited to those with positively charged side chains For each position, which amino acid is more commonly found ... 

Under conditions when the average rate of protein catabolism is increased, such as during insulin deprivation, amino acid limitation, or serum deprivation, inhibitors or lysosomotropic amines partially inhibit the enhanced protein degradation. However, effects on normal or basal protein catabolism are controversial. Some workers (122, 123)... 

Excess amino acids 4 x 10" M. Amino acid limitation was achieved in a chemostat. 

A suboptimal content of one amino acid limits animal growth, and nitrogen of the other amino acids present in excess will be excreted. Thus, plant-based feeds can be fortified by adding the limiting amino acids to achieve the right nutrient balance [9,13]. This is beneficial not only for animal growth but also for the environment. The L-lysine content of soybean meal (2.7-2.9% of L-lysine) is about... 

Ainslie et al (1993) used the CNCPS to evaluate growth when ME, MP, or essential amino acids limited growth. The ME allowable ADG alone had an r of 0.70 and a bias of 25% across all treatments. However, when ME, MP, or essential amino acid allowable growth was used, the r and bias were 0.82 and 3%, respectively. These results and those in other studies have suggested ME efficiency is reduced when protein, essential amino acids or other nutrients are not adequate to support the ME allowable growth. It is apparent that nutrient deficiencies or excesses impact efficiency of utilization of ME and consequently, kg can be accurately assessed only if the diets in use are nutritionally balanced. 

Sensitivity levels more typical of kinetic studies are of the order of lO molecules cm . A schematic diagram of an apparatus for kinetic LIF measurements is shown in figure C3.I.8. A limitation of this approach is that only relative concentrations are easily measured, in contrast to absorjDtion measurements, which yield absolute concentrations. Another important limitation is that not all molecules have measurable fluorescence, as radiationless transitions can be the dominant decay route for electronic excitation in polyatomic molecules. However, the latter situation can also be an advantage in complex molecules, such as proteins, where a lack of background fluorescence allow s the selective introduction of fluorescent chromophores as probes for kinetic studies. (Tryptophan is the only strongly fluorescent amino acid naturally present in proteins, for instance.)... 

Chiral stationary phases in tic have been primarily limited to phases based on normal or microcrystalline cellulose (44,45), triacetylceUulose sorbents or siHca-based sorbents that have been chemically modified (46) or physically coated to incorporate chiral selectors such as amino acids (47,48) or macrocyclic antibiotics (49) into the stationary phase. 

Most of the bacteria, yeasts, molds, and higher fungi of interest for SCP production are deficient in methionine and must be supplemented with this amino acid to be suitable for animal feeding or human food appHcations. Also, lysine—arginine ratios should be adjusted in poultry rations in which yeast SCP is used (62). Human feeding studies have shown that only limited quantities of yeast such as Candida utilis can be added to food products without adverse effects on flavor (63). 

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