Description
Succinic acid, C4H6O4, occurs under physiological conditions as the anion succinate2-, M, with pKa1 = 4.2 and pKa2 = 5.6. Succinate is formed in the TCA cycle, and is a substrate of CII, reacting to fumarate and feeding electrons into the Q-junction. Succinate (CII-linked) and NADH (CI-linked) provide convergent electron entries into the Q-junction. Succinate is transported across the inner mitochondrial membrane by the dicarboxylate carrier.
Abbreviation: S
Reference: Gnaiger 2012 MitoPathways
MitoPedia topics: Substrate and metabolite
Application in HRR
S: Succinate (Succinate disodium salt, hexahydrate, C4H404Na2 * (H2O)6); Sigma S 2378, 100 g, store at RT; FW = 270.1
Preparation of 1 M stock solution (dissolved in H2O):
- 1) Weigh 1.3505 g of succinate and dissolve in 3 ml H2O.
- 2) Check pH and adjust to 7.0 if necessary with 1 N HCl (usually the pH is 7 without any adjustment).
- 3) Transfer to 5 ml volumetric glass flask and adjust the final volume to 5 ml.
- 4) Divide into 0.5 ml portions.
- 5) Store frozen at -20 Β°C.
Oxygraph-2k manual titrations: MiPNet09.12 O2k-Titrations
- In the absence of CI-linked substrates, add the CI-inhibitor rotenone before addition of succinate, to avoid accumulation of oxaloacetate with subsequent inhibition of succiante dehydrogenase.
- When keeping the succinate stock solution on ice, check for complete solubilization of succinate and warm in your hands if necessary.
- Titration volume: 20 Β΅l using a 50 Β΅l syringe (2 ml O2k-chamber).
- Final concentration: 10 mM.