A radioisotope assay for L-glutaminase: the measurement of tritiated water formation from the reaction of L-[2-3H]glutamine with the L-glutaminase and glutamate oxalacetate transaminase couple.

@article{Zielke1982ARA,
  title={A radioisotope assay for L-glutaminase: the measurement of tritiated water formation from the reaction of L-[2-3H]glutamine with the L-glutaminase and glutamate oxalacetate transaminase couple.},
  author={C. Zielke and H. R. Zielke and P. Ozand},
  journal={Analytical biochemistry},
  year={1982},
  volume={127 1},
  pages={
          134-42
        }
}
Abstract An assay for the determination of l -glutaminase in extracts and intact cells is described. The method is based on the stereospecific release of 3 H 2 O from l -[2- 3 H]glutamine when l -glutaminase is coupled to l -aspartate:2-oxoglutarate amino transferase. The substrate, glutamine, and intermediate product, glutamate, are separated from the final reaction product, tritiated water, on a mixed-bed ion-exchange column which retains amino acids and organic acids but not water. The… Expand
Functional intracellular glutaminase activity in intact astrocytes
TLDR
Evidence is provided that phosphate-activated glutaminase activity in vivo is regulated by cellular metabolites, that its “functional” activity is 5–9% of the rate obtained using extracts, and this ‘functional’ activity is sufficient to account for the rate of glutamine oxidation. Expand
Glutamine Metabolism by Cultured Mammalian Cells
Cultured mammalian cells are grown in medium containing carbohydrates, amino acids, salts, vitamins, and growth factors. In the 1950’s Eagle [1] identified the basic composition of tissue cultureExpand
Characterization of glutamine metabolism in two related murine hybridomas.
TLDR
The relative enzyme activities and the amount of ammonia produced during growth indicated that glutamine is oxidized preferentially via the transamination pathway and suggests that transport may regulate glutamine metabolism. Expand

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