Concerted feedback inhibition of aspartokinase activity from Pseudomonasfluorescens by the combination of L-threonine and r.-lysine, or by L-threonine and L-methionine was freely and rapidly reversible. Inhibition by L-threonine, or by the concerted pairs of amino acids was kinetically “mixed” with respect to L-aspartate and noncompetitive with regard to ATP. In the presence of L-threonine the ...

In order to describe the response of broiler breeder hens to dietary amino acids and to develop an effective model for the precise feeding of these birds after sexual maturity, accurate estimates of the amounts of each amino acid required for maintenance and egg production are needed. The maintenance requirement for threonine and lysine were estimated in two different experiments by measuring t...

The present study was aimed at investigating the role of in ovo administered amino acids: lysine, arginine, threonine or methionine plus cysteine (Met+Cys) in 14-day embryos on expression profile of growth (chicken growth hormone (cGH), insulin like growth factors (IGF) I and II, and mucin) and immunity related genes (IL-2, IL-4, IL-6, IL-12, TNF-α, and IFN-γ). On incubation day (ID) 18, higher...

We have developed an experimental model of the whole threonine pathway that allows us to study the production of threonine from aspartate under different conditions. The model consisted of a desalted crude extract of Escherichia coli to which we added the substrates and necessary cofactors of the pathway: aspartate, ATP and NADPH. In this experimental model we measured not only the production o...