Phenylalanine and tyrosine catabolism

Tyrosine and phenylalanine catabolism by Lactobacillus cheese flavor adjuncts.

Bacterial metabolism of Tyr and Phe has been associated with the formation of aromatic compounds that impart barny-utensil and floral off-flavors in cheese. In an effort to identify possible mechanisms for the origin of these compounds in Cheddar cheese, we investigated Tyr and Phe catabolism by Lactobacillus casei and Lactobacillus helveticus cheese flavor adjuncts under simulated Cheddar chee...

L-Phenylalanine and L-tyrosine catabolism by selected Streptomyces species.

L-Phenylalanine and L-tyrosine were completely catabolized through homogentisate by Streptomyces setonii 75Vi2 but only partially degraded by Streptomyces badius 252, Streptomyces sioyaensis P5, Streptomyces viridosporus T7A, and Streptomyces sp. strain V7. Intermediates of catabolism were confirmed by thin-layer, gas, and high-pressure liquid chromatography. Homogentisate 1,2-dioxygenase was p...

Postprandial body protein synthesis and amino acid catabolism measured with leucine and phenylalanine-tyrosine tracers.

Whether phenylalanine-tyrosine (Phe-Tyr) tracers yield estimates of postprandial protein synthesis comparable to those of the widely used leucine (Leu) tracer is unclear. We measured Leu oxidation (Ox), Phe hydroxylation (Hy), and their disposal into whole body protein synthesis before and after the administration of a mixed meal (62 kJ/kg body wt, 22% of energy as protein), over 4 h in healthy...

Comparison of phenylalanine and tyrosine in urine of patients with vitiligo and normal subjects

Amino acids are one of the most necessary substances in intracellular metabolic processes.aromatic aminoacids such as phenylalanine and tyrosine are precursor of melanin so are important materials for the skin pigmentation.metabolic disorders in the melanin synthesis causes milky macules on the skin of patients,known as vitiligo.these patients are hypersensitive to sunlight and consequently at ...

Phenylalanine Hydroxylase, Tyrosine Hydroxylase, and Tryptophan Hydroxylase