Glutamate

high-resolution terminology - matching measurements at high-resolution

Glutamate

Description

Glutamic acid, C₅H₉NO₄, is an amino acid which occurs under physiological conditions mainly as the anion glutamate^-, G, with pK_a1 = 2.1, pK_a2 = 4.07 and pK_a3 = 9.47. Glutamate&malate is a substrate combination supporting an N-linked pathway control state, when glutamate is transported into the mt-matrix via the glutamate-aspartate carrier and reacts with oxaloacetate in the transaminase reaction to form aspartate and oxoglutarate. Glutamate as the sole substrate is transported by the electroneutral glutamate^-/OH^- exchanger, and is oxidized in the mitochondrial matrix by glutamate dehydrogenase to α-ketoglutarate (2-oxoglutarate), representing the glutamate-anaplerotic pathway control state. Ammonia (the byproduct of the reaction) passes freely through the mitochondrial membrane.

Abbreviation: G

Reference: Gnaiger 2020 BEC MitoPathways

Application in HRR

G: Glutamate (L-Glutamic acid, monosodium salt hydrate; C₅H₈NNaO₄ · xH₂O), Sigma-Aldrich: G1626, store at RT, CAS: 142-47-2, M = 169.1 g·mol^-1

Preparation of 2 M stock solution (dissolved in H₂O)

1. Weigh 1.691 g L-Glutamic acid, monosodium salt hydrate.
2. Add 4 mL H₂O.
3. Check pH and adjust to 7.0 if necessary with 5 M KOH (usually the pH is 7 without any adjustment);
4. Transfer to a 5 mL volumetric glass flask, adjust final volume to 5 mL and divide into 0.5 mL portions.
5. Store at -20 °C.

» Oroboros manual titrations MiPNet09.12 Manual titrations of SUIT chemicals

• Titration volume (2-mL O2k-chamber): 10 µL using a 25 µL Hamilton syringe.
• Titration volume (0.5-mL O2k-chamber): 2.5 µL using a 10 µL Hamilton syringe
• Experimental concentration: 10 mM.

References

• Herbst EA, Holloway GP (2016) Exercise increases mitochondrial glutamate oxidation in the mouse cerebral cortex. Appl Physiol Nutr Metab 41:799-801. - »Bioblast link«

MitoPedia topics: Substrate and metabolite