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 ...

The catabolic L-serine (L-threonine) deaminase of Saccharomyces cerevisiae allows the yeast to grow on media with L-serine or L-threonine as sole nitrogen source. A mutant, cha1 (catabolism of hydroxyamino acids), lacking this enzyme activity has been isolated. We have cloned the CHA1 gene by complementation of a cha1 mutation. Northern analysis showed that CHA1 mRNA has a size of about 1200 ri...

Threonine dehydrase (deaminase), which catalyzes the conversion of I,-threonine to a-ketobutyrate and ammonia, has been observed in crude extracts prepared from a number of different organisms (1-13). Frequently these same extracts also act on L-serine to form pyruvate and ammonia. Table I summarizes the available data on the serine and threonine dehydrasel activities in crude extracts from var...

BACKGROUND Saccharomyces cerevisiae (baker's yeast) has great potential as a whole-cell biocatalyst for multistep synthesis of various organic molecules. To date, however, few examples exist in the literature of the successful biosynthetic production of chemical compounds, in yeast, that do not exist in nature. Considering that more than 30% of all drugs on the market are purely chemical compou...

The behavior of threonine residues in the bacteriorhodopsin (bR) photocycle has been investigated by Fourier transform infrared difference spectroscopy. L-Threonine labeled at the hydroxyl group with 18O (L-[3-(18)O]threonine) was incorporated into bR and the bR-->M FTIR difference spectra measured. Bands are assigned to threonine vibrational modes on the basis of 18O induced isotope frequency ...