BACKGROUND Plasma threonine concentrations are elevated in infants fed formula containing a whey-to-casein protein ratio of 60:40 compared with concentrations in infants fed formula containing a ratio of 20:80 or human milk (60:40). OBJECTIVE We studied whether degradation of excess threonine was lower in formula-fed infants than in infants fed their mothers' milk. DESIGN Threonine kinetics...

The catabolic L-serine (L-threonine) dehydratase of Saccharomyces cerevisiae allows the yeast to grow on media with L-serine or L-threonine as sole nitrogen source. Previously we have cloned the CHA1 gene by complementation of a mutant, cha1, lacking the dehydratase activity. Here we present the DNA sequence of a 1,766-bp fragment of the CHA1 region encompassing an open reading frame of 1080 bp...

BACKGROUND Deletion of large blocks of nonessential genes that are not needed for metabolic pathways of interest can reduce the production of unwanted by-products, increase genome stability, and streamline metabolism without physiological compromise. Researchers have recently constructed a reduced-genome Escherichia coli strain MDS42 that lacks 14.3% of its chromosome. RESULTS Here we describ...

In order to clarify the mechanism of activation of L-threonine deaminase by adenosine diphosphate, the enzyme was purified about 700.fold from sonic extracts of Closlridium tetanomorphum, and kinetic and ADP-binding studies were carried out. Plots of reaction rates against L-threonine concentrations gave a sigmoid curve in the absence of ADP, whereas a hyperbolic curve was obtained in the prese...

In 1939 Gladstone clearly demonstrated the phenomenon of amino acid antagonism and showed its relationship to the nutrition of the pathogen Bacillus anthracis. Among the interrelationships involving specific amino acids was the ability of threonine to remove the toxic effects of serine and vice versa. Snell and Guirard (1943) noted the inhibition of growth of Streptococcus lactis by glycine, se...

The activity of the enzyme threonine dehydrase in the livers of mice and rats is increased by the intraperitoneal injection of threonine, while that of serine dehydrase shows no change. The injection of a comparable amount of L-serine produces no increase in the activity of either L-serine dehydrase or L-threonine dehydrase. This is substantiating evidence that these two dehydrases are separate...

Two independent experiments were conducted with broilers to determine the effect of threonine and vitamin A on immune system. In first experiment, dietary treatments contained 0.8%, 0.87%, 0.94 % and 1.01 % total threonine. In second experiment, diets were as follows: basal diet without vitamin A; basal diet plus 1500 IU/Kg vitamin A; basal diet plus 6250 IU/Kg vitamin A; basal diet plus 11000 ...

Sir: In a previous communication^ to this Jour nal, the isolation of N-methyl-L-threonine from acid hydrolysates of stendomycin2~4) was briefly mentioned. We wish to report here some experiments that led to the final assignment of the configuration for this amino acid with two centers of asymmetry. The specific rotation of the N-methyl amino acid from stendomycin was in good agreement with the ...