A fragmentation mechanism for the neutral loss of 73 Da from dimethylformamidine glutamine isobutyl ester is investigated. Understanding this mechanism will allow to improve the identification and quantification of 15N-labeled and unlabeled glutamine and the distinguishing of glutamine and glutamic acid by electrospray ionization (ESI)-tandem mass spectrometry. Before mass spectrometry analysis...

Glutamine is the most abundant free amino acid of the human body. Besides its role as a constituent of proteins and its importance in amino acid transamination, glutamine has regulatory capacity in immune and cell modulation. Glutamine deprivation reduces proliferation of lymphocytes, influences expression of surface activation markers on lymphocytes and monocytes, affects the production of cyt...

Glutamine dependence is a prominent feature of cancer metabolism, and here we show that melanoma cells, irrespective of their oncogenic background, depend on glutamine for growth. A quantitative audit of how carbon from glutamine is used showed that TCA-cycle-derived glutamate is, in most melanoma cells, the major glutamine-derived cataplerotic output and product of glutaminolysis. In the absen...

In certain lines of hepatoma tissue-culture cells, the extracellular glutamine concentration regulates the specific activity of glutamine synthetase. By quantifying the radioactivity in immunoprecipitated glutamine synthetase on polyacrylamide gels, we found that the rate of degradation, but not of synthesis, of glutamine synthetase is a sensitive function of extracellular glutamine. The activi...

Malnutrition is an unfavorable background for the course and outcome of viral diseases, including COVID-19. In accordance with international recommendations, timely correction nutritional status using oral, tube enteral parenteral nutrition a necessary mandatory method concomitant therapy An analytical review results studies on clinical use pharmacological nutrients (glutamine; vitamins A, C, D...

In the previous issue of Critical Care, Mori and colleagues demonstrate that glutamine supplementation in mechanically ventilated patients as part of parenteral nutrition increases plasma glutamine concentration and glutamine utilization, but does not mitigate protein degradation and even increases de novo glutamine production. Studies suggest that protein degradation is regulated by the degree...

Mutants of the cyanobacterium Anabaena variabilis that were capable of increased uptake of glutamine, as compared with that in the parental strains, were isolated. Growth of these mutants and their parental strains was measured in media containing N2, ammonia, or glutamine as a source of nitrogen. All strains grew well with any one of these sources of fixed nitrogen. Much of the glutamine taken...

Abstract In this report we present XPS data for five amino acids (AAs) (tryptophan, methionine, glutamine, glutamic acid, and arginine) with different side chain groups measured in solid state (powder form). The theoretically experimentally obtained chemical structure of AAs are compared. Here, analyse discuss C 1 s, N O 1s S 2p core level binding energies, FWHMs, atomic concentrations the func...

Glutamine is purported to inhibit recycling of citrulline to arginine and to limit nitric oxide release in vitro. However, vasoactive effects of glutamine have not been clearly demonstrated in vivo. During hyperammonemia, impaired cerebrovascular reactivity to CO(2) is related to glutamine accumulation. We tested the hypotheses that 1) glutamine infusion in the absence of hyperammonemia impairs...