Nanofiber membranes for chiral separation were prepared from chitin, which is the most abundant natural amino polysaccharide. The membrane showed chiral separation ability by adopting concentration gradient as a driving force for membrane transport. In other words, the chitin nanofiber membrane selectively transported the D-isomer of glutamic acid (Glu), phenylalanine (Phe), and lysine (Lys) fr...

The aromatic amino acids phenylalanine, tyrosine and tryptophan in plants are not only essential components of protein synthesis, but also serve as precursors for a wide range of secondary metabolites that are important for plant growth as well as for human nutrition and health. The aromatic amino acids are synthesized via the shikimate pathway followed by the branched aromatic amino acid metab...

BACKGROUND A phenylalanine-free amino acid based protein substitute is necessary to provide the major source of protein in phenylketonuria (PKU). Protein substitutes in PKU are usually given as drinks. These are unpalatable and compliance is often poor. Tablets containing a suitable mixture of phenylalanine-free amino acids (Aminogran Food Supplement, UCB) are now available. AIMS To compare t...

The effects of phytic acid and 2 sources of exogenous phytase (bacterial vs. fungal) on the flow of endogenous amino acids at the terminal ileum of broilers were assessed using the enzyme-hydrolyzed casein method. Phytic acid (as the sodium salt) was included in a purified diet at 8.5 and 14.5 g/kg, and each diet was fed without or with a fungal (Aspergillus niger-derived) or a bacterial (Esche...

Beauvericin synthetase, a multifunctional enzyme catalyzing depsipeptide formation in Beauveria bassiana was purified to near homogeneity. The enzyme consists of a single polypeptide chain with a molecular mass of about 250 kdaltons. The mechanism of beauvericin formation is very similar to that of the cyclohexadepsipeptide enniatin. The constituents of the beauvericin molecule, L-phenylalanine...

Incorporation of L-[2-2H]phenyl-[2-2H]alanine and L-phenyl-[2-13C, 15N]alanine into cytochalasin D by Zygosporium masonii involved the complete loss of both the alpha-2H- and the alpha-15N-atom. Incorporation of a mixture of L-phenyl-[15N]alanine and L-[U-14C]phenylalanine into cytochalasin D and protein amino acids (phenylalanine, leucine, isoleucine) was accompanied by a substantial loss of 1...

Glycylasparagine has been found to be more effective than aspartic acid in reversing the inhibition of adaptive enzyme synthesis by cysteic acid or P-hydroxyaspartic acid or combinations of these synergistic inhibitors (1). The results were interpreted to indicate a pathway of utilization of the peptide not involving the inhibited enzymatic utilization of the free amino acid. Also, histidine pe...

The results of the assessment amino acid profile longest muscle back Kemerovo breed pigs and its two-breed three-breed crosses with commercial breeds are presented. largest amount acids is found in meat purebred animals comparison two- threebreed animals. In terms content such as phenylalanine, aspartic acid, serine, glutamic significantly exceeded hybrids. It was shown that studied groups for ...

Phenylalanine in serum and urine was determined by gas chromatography after it was converted, by action of nitrous acid, to the corresponding hydroxy acid, phenyllactic acid. After extraction with ether, the phenyllactic acid was derivatized with bis(trimethylsilyl) trifluoroacetamide under mild conditions, and the product was injected directly into the gas chromatograph. The precision of the m...

Knowledge of the growth factor requirements of various lactic acid bacteria, especially Lactobacillus casei and L. arabinosus 17-5, has led to the development of useful microbiological methods for the quantitative determination of most-of the B vitamins. Recently attention has turned to the amino acid requirements of the lactobacilli. The amino acids necessary for growth of L. casei and L. arab...