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Determination of phosphate-activated glutaminase activity and its kinetics in mouse tissues using metabolic mapping (quantitative enzyme histochemistry).

Botman D, Tigchelaar W, Van Noorden CJ - J. Histochem. Cytochem. (2014)

Bottom Line: PAG activity was decreased to 22% in the presence of 2 mM 6-diazo-5-oxo-L-norleucine.When compared with liver, kidney and brain, other tissues showed 3-fold to 6-fold less PAG activity.In conclusion, PAG is mainly active in mouse kidney, brain and liver, and shows different kinetics depending on which type of PAG is expressed.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (DB, WT, CJFVN).

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(A) Kinetics of phosphate-activated glutaminase (PAG) activity in mouse kidney and brain tissue sections plotted against glutamine concentration. (B) Kinetics of PAG activity in mouse liver tissue sections plotted against various glutamine concentrations. Bars indicate SEM (n=3).
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fig7-0022155414551177: (A) Kinetics of phosphate-activated glutaminase (PAG) activity in mouse kidney and brain tissue sections plotted against glutamine concentration. (B) Kinetics of PAG activity in mouse liver tissue sections plotted against various glutamine concentrations. Bars indicate SEM (n=3).

Mentions: PAG showed two distinct patterns of enzyme kinetics (Fig. 7, Table 1). In liver sections, a sigmoidal curve of the reaction velocity versus glutamine concentration was obtained, indicating allosteric regulation of PAG activity. As compared with PAG kinetics in brain and kidney, L-PAG exhibited a relatively high Km of 11.6 mM and a low Vmax of 0.54 µmol/mL/min. PAG kinetics in the brain and kidney showed K-PAG characteristics with Michaelis-Menten kinetics, a relatively low Km for glutamine of 0.6 mM, and a high Vmax of 1.1 µmol/mL/min.


Determination of phosphate-activated glutaminase activity and its kinetics in mouse tissues using metabolic mapping (quantitative enzyme histochemistry).

Botman D, Tigchelaar W, Van Noorden CJ - J. Histochem. Cytochem. (2014)

(A) Kinetics of phosphate-activated glutaminase (PAG) activity in mouse kidney and brain tissue sections plotted against glutamine concentration. (B) Kinetics of PAG activity in mouse liver tissue sections plotted against various glutamine concentrations. Bars indicate SEM (n=3).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2 - License 3
Show All Figures
getmorefigures.php?uid=PMC4230542&req=5

fig7-0022155414551177: (A) Kinetics of phosphate-activated glutaminase (PAG) activity in mouse kidney and brain tissue sections plotted against glutamine concentration. (B) Kinetics of PAG activity in mouse liver tissue sections plotted against various glutamine concentrations. Bars indicate SEM (n=3).
Mentions: PAG showed two distinct patterns of enzyme kinetics (Fig. 7, Table 1). In liver sections, a sigmoidal curve of the reaction velocity versus glutamine concentration was obtained, indicating allosteric regulation of PAG activity. As compared with PAG kinetics in brain and kidney, L-PAG exhibited a relatively high Km of 11.6 mM and a low Vmax of 0.54 µmol/mL/min. PAG kinetics in the brain and kidney showed K-PAG characteristics with Michaelis-Menten kinetics, a relatively low Km for glutamine of 0.6 mM, and a high Vmax of 1.1 µmol/mL/min.

Bottom Line: PAG activity was decreased to 22% in the presence of 2 mM 6-diazo-5-oxo-L-norleucine.When compared with liver, kidney and brain, other tissues showed 3-fold to 6-fold less PAG activity.In conclusion, PAG is mainly active in mouse kidney, brain and liver, and shows different kinetics depending on which type of PAG is expressed.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (DB, WT, CJFVN).

Show MeSH