α-Ketoglutaric acid



Synonyms: 2-Ketoglutaric acid, α-ketoglutarate, 2-oxoglutaric acid, 2-oxoglutarate.
Method(s): GC-MS/MS (1).

What is measured on the same platform, click here.
Platform B: MMA, tHcy, tCys, Met, Ser, Gly, Cysta, Sarc, His, Trp, Kyn, (KTR), HK, KA, XA, AA, HAA, NA, PA, Figlu, Orn, Asp, Glu, Lys, Ala, Phe, Ile, Leu, Pro, Val, Asn, Gln, Thr, Tyr, aKG, 3HIB, aHB, bHB, AcAc

What is α-ketoglutaric acid?

α-Ketoglutaric acid is a keto acid of the Krebs cycle that is converted to succinate through the action of the thiamine pyrophosphate (TPP) -dependent enzyme, α-ketoglutarate dehydrogenase. α-Ketoglutaric acid is also connected to glutamic acid metabolism through the pyridoxal 5´-phosphate-dependent transamination reaction. The α-ketoglutarate:glutamate ratio is almost doubled after dietary vitamin B-6 restriction, suggesting that the ratio may serve as a functional marker of vitamin B6 status (2).

Performance of the assay

Lower limit of detection (LOD): na.
Within-day CV: 5 %; between-day CV: na.

Indication(s)

α-Ketoglutaric acid may be a marker of thiamine deficiency.
The α-ketoglutarate:glutamate ratio is a putative marker of vitamin B6 status.

Specimen, collection and processing

Patient/subject: No special precaution.
Matrix: Serum or EDTA plasma.
Volume: Minimum volume is 50 µL, but 200 µL is optimal and allows reanalysis.
Preparation and stability: Probably stable.

Transportation; for general instruction on transportation, click here.

Frozen, on dry ice.

Reported values, interpretation

Reported values: 20-50 µmol/L
Intraclass correlation coefficient (ICC): na.

Literature

1. Midttun, Ø., McCann, A., Aarseth, O., Krokeide, M., Kvalheim, G., Meyer, K., and Ueland, P.M. (2016). Combined measurement of 6 fat-soluble vitamins and 26 water-soluble functional vitamin markers and amino acids in 50 μL of serum or plasma by high-throughput mass spectrometry. Anal Chem 88, 10427-436.
2. Gregory, J.F., Park, Y., Lamers, Y., Bandyopadhyay, N., Chi, Y.Y., Lee, K., Kim, S., da Silva, V., Hove, N., et al. (2013). Metabolomic analysis reveals extended metabolic consequences of marginal vitamin B-6 deficiency in healthy human subjects. PLoS One 8, e63544.