Urea is the major nitrogen (N) form supplied as fertilizer in agriculture, but it is also an important N metabolite in plants. Urea transport and assimilation were investigated in Arabidopsis (Arabidopsis thaliana). Uptake studies using (15)N-labeled urea demonstrated the capacity of Arabidopsis to absorb urea and that the urea uptake was regulated by the initial N status of the plants. Urea up...

SUMMARY Urea cycle defect is an inborn error of ammonium metabolism caused by a deficient activity of the enzymes involved in urea synthesis. Localized short-TE proton MR spectroscopy, performed in two infants who had citrullinemia and ornithine transcarbamylase deficiency, respectively, showed a prominent increase of glutamine/glutamate and lipid/lactate complex in both cases. N-acetylaspartat...

UNLABELLED Prostate-specific membrane antigen (PSMA) is highly expressed in prostate cancer, and small-molecule radiopharmaceuticals targeting PSMA rapidly detect the location and extent of disease. Here we evaluated preclinically 4 novel (99m)Tc-labeled small-molecule inhibitors of PSMA with the potential for clinical translation for molecular imaging of prostate cancer in humans. METHODS Fo...

This study examines the role of glucagon and insulin in the incorporation of N derived from N-labeled glutamine into aspartate, citrulline and, thereby, [N]urea isotopomers. Rat livers were perfused, in the nonrecirculating mode, with 0.3 mM NH4Cl and either 2Nor 5-N-labeled glutamine (1 mM). The isotopic enrichment of the two nitrogenous precursor pools (ammonia and aspartate) involved in urea...

Lysine as an essential amino acid supplemented to fulfil the dietary requirement of Poultry feed. In Pakistan all this demand is accomplished by importing lysine for feed sector. Wild Brevibacterium flavum was used to induce mutation by random mutagenesis for hyper production of lysine through fermentation. The highest lysine producing strain (BFENU2) was screened with 21.64 g/L production by m...

Fungi produce α-aminoadipate, a precursor for penicillin and lysine via the α-aminoadipate pathway. Despite the biotechnological importance of this pathway, the essential isomerization of homocitrate via homoaconitate to homoisocitrate has hardly been studied. Therefore, we analysed the role of homoaconitases and aconitases in this isomerization. Although we confirmed an essential contribution ...

Glutamate dehydrogenase (GLDH) catalyzes reversible deamination of glutamate into alpha-ketoglutarate and ammonium ion. In the metabolism a cell, GLDH has key role acting as an interface between carbohydrates amino acids in vicinity citric acid cycle urea cycle. brain, appears astrocytic processes associated with glutamatergic terminals, but it is also involved glia metabolic processes. probabl...

1. Two carbons, carbon-2 and one of carbons-3 to -5, of lysine seemed likely to be incorporated into one of carbon of the chromophore moiety of formycin. 2. From the results of radioisotopic studies with glutamate, gamma-amino-n-butyrate or organic acids related to tricarboxylic acid cycle, the important role of glutamate in the biosynthesis of formycin was strongly suggested. 3. The incorporat...

RGS proteins are GTPase-activating proteins (GAPs) for G protein alpha-subunits. This GAP activity is mediated by the interaction of conserved residues on regulator of G protein signaling (RGS) proteins and Galpha-subunits. We mutated the important contact sites Glu-89, Asn-90, and Asn-130 in RGS16 to lysine, aspartate, and alanine, respectively. The interaction of RGS16 and its mutants with Ga...

X-ray diagrams from oriented fibers of poly-s-carbobenzoxy-T,-lysine and a n e w form of poly7-methyl-T,-glutamate have been obtained. Spacing calculations and rough equatorial intensity measurements from the poly-s-carbobenzoxy-L-lysine photographs indicate tha t the molecules of this substance have the 3.60-residue a-helix configuration with one molecule in a simple hexagonal unit cell, a 0 -...