D-α-Hydroxyglutaric acid disodium [Disodium (R)-2-Hydroxyglutarate] is a competitive inhibitor of α-ketoglutarate-dependent dioxygenases with a Ki of 0.628 mM.

α-ketoglutarate-dependent dioxygenase:0.628 mM(Ki)

In U-87 mg cells, D-α-Hydroxyglutaric acid disodium acts as weak antagonists of α-KG to inhibit α-KG-dependent histone demethylases and increases dimethylation on both H3K9 and H3K79. [1] Besides, D-α-Hydroxyglutaric acid disodium inhibits ATP synthase and mTOR signaling, and thus causes growth arrest and tumor cell killing. [2]

Enzymatic Assays: To assay human JHDM1A/KDM2A demethylase activity toward H3K36me2, His tagged JHDM1A is first obtained by transforming pET28a-JHDM1A into Escherichia coli BL21 and protein expression is induced by addition of 1 mM IPTG at 30° C when cell density reaches 0.5 OD600 units. Cells are lysed by sonication and Ni-NTA agarose is used to purify His-JHDM1A fusion proteins. Histone demethylase assay is carried out by incubating 2 μg oligonucleosomes, 4 μg purified His-JHDM1A, and/or 10–50 mM L- or D-2-HG in histone demethylation buffer [50 mM HEPES (pH 8.0), 625 μM Fe(NH4)2(SO4)2, 0.1–0.5 mM α-KG, 2 mM ascorbate] at 37° C for 2–3 hr and the reactions are stopped by the addition of SDS loading buffer and subsequently analyzed by western blotting using anti-H3K36me2 antibody. To measure CeKDM7A demethylase activity toward H3K9me2 and H3K27me2, two synthetic dimethylated peptides H3K9me2 [ARTKQTARK (me2)STGGKA] and H3K27me2 [QLATKAARK (me2)SAPAS] are used as substrates. Demethylase assays are carried out in the presence of 10 μg enzyme, 1 μg peptide in 20 μl buffer 20 mM Tris-HCl (pH 7.5), 150 mM NaCl, 50 μM Fe(NH4)2(SO4)22, 100 μM α-KG, 2 mM Vc, 10 mM PMSF for 3 hr. The demethylation reaction mixture is desalted by passing through a C18 ZipTip. To examine the inhibitory effect of 2-HG, various concentrations of 2-HG are incubated with KDM7A briefly before adding other reaction mixtures. The samples are analyzed by a MALDI-TOF/TOF mass spectrometer.

Cells are seeded in 12-well plates and, after overnight incubation, treated with the indicated concentrations of each compound. After harvesting, cells are stained with acridine orange (AO) and 4′,6-diamidino-2-phenylindole (DAPI). Cell number and viability are measured based on AO and DAPI fluorescence as measured by NC3000 following the manufacturer's instructions.(Only for Reference)