Staphylococcus aureus Mu50, which has reduced susceptibility to vancomycin, has a remarkably thickened cell wall with an increased proportion of glutamine nonamidated muropeptides. In addition, Mu50 had enhanced glutamine synthetase and L-glutamine D-fructose-6-phosphate aminotransferase activities, which are involved in the cell-wall peptidoglycan synthesis pathway. Furthermore, significantly ...

The uptake of branched-chain amino acids (BCAA) from plasma by lactating porcine mammary gland substantially exceeds their output in milk, whereas glutamine output is 125% greater than its uptake from plasma. In this study, we tested the hypothesis that BCAA are catabolized for glutamine synthesis in mammary tissue. Mammary tissue slices from sows on d 28 of lactation were incubated at 37 degre...

To further explore the function of NADH-dependent glutamate synthase (GOGAT), the tissue distribution of NADH-GOGAT protein and activity was investigated in rice (Oryza sativa L.) leaves. The distributions of ferredoxin (Fd)-dependent GOGAT, plastidic glutamine synthetase, and cytosolic glutamine synthetase proteins were also determined in the same tissues. High levels of NADH-GOGAT protein (33...

Recently, we demonstrated that supplementing (with 3 mg Se per day) the diets of growing beef steers grazing on Se-deficient toxic endophyte-infected tall fescue-based forage with either organic (OSe, SEL-PLEX) or a 1:1 blend (MIX) OSe and inorganic (ISe, sodium selenite) in vitamin–mineral mixes, rather than forms Se, ameliorated several classic serum symptoms fescue toxicosis. Importantly, hi...

We have examined properties of nicotinamide adenine dinucleotide (NAD) synthetase from human erythrocytes. The enzyme was found to be cold labile and extremely unstable in crude hemolysate, with complete loss of activity occurring after 24 hours at 4 degrees C. However, maintenance of crude hemolysate at 20 to 25 degrees C in the presence of EDTA and KCl increased NAD synthetase stability subst...

The properties of the anthranilate synthetase complex and its separated subunits were compared in catalyzing the anthranilate synthetase reaction, chorismate + l-glutamine or NH(4) (+) --> anthranilate, and the transferase reaction, anthranilate + 5'-phosphorylribosyl-1-pyrophosphate --> phosphoribosyl anthranilate. It is shown that anthranilate synthetase component I is activated by normal ant...

1. On perfusion of livers from fed rats with a semi-synthetic medium containing no added amino acids there is a rapid release of glutamine during the first 15min (15.6+/-0.8mumol/h per g wet wt.; mean+/-s.e.m. of 35 experiments), followed by a low linear rate of production (3.6+/-0.3mumol/h per g wet wt.; mean+/-s.e.m. of three experiments). The rapid initial release can be accounted for as was...

Glutamine synthetase, a key enzyme in the production of glutamine, is known to be induced by glucocorticoids and preserved in skeletal muscle during aging, but the effect of other steroids, such as sex steroids (progesterone, estradiol), is unknown in vivo. The aim of this study was to determine whether progesterone or estradiol plays a role in the regulation of glutamine synthetase (GS) with a...

Glutamine synthetase from ovine brain has a critical arginine residue at the catalytic site (Powers, S. G., and Riordan, J.F. (1975) Proc. Natl. Acad. Sci. U.S. A. 72, 2616-2620). This enzyme is now shown to be a substrate for a purified NAD:arginine ADP-ribosyltransferase from turkey erythrocyte cytosol that catalyzes the transfer of ADP-ribose from NAD to arginine and purified proteins. The t...

The aim of this study was to determine the immunoreactivity of neuronal and inducible nitric oxide synthetase, argininosuccinate synthetase, argininosuccinate lyase, glutamine synthetase in different regions of brain in rats of kainic acid mediated epilepsy. Male Sprague-Dawley rats were used in this study. The acute group animals were sacrificed after 2 hours and the chronic group animals were...