|Preferred IUPAC name
3D model (JSmol)
CompTox Dashboard (EPA)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
It is an important intermediate in the citric acid cycle, where it is synthesized from α-ketoglutarate by α-ketoglutarate dehydrogenase through decarboxylation. During the process, coenzyme A is added.
With B12 as an enzymatic cofactor, it is also synthesized from propionyl CoA, the odd-numbered fatty acid, which cannot undergo beta-oxidation. Propionyl-CoA is carboxylated to D-methylmalonyl-CoA, isomerized to L-methylmalonyl-CoA, and rearranged to yield succinyl-CoA via a vitamin B12-dependent enzyme. While Succinyl-CoA is an intermediate of the citric acid cycle, it cannot be readily incorporated there because there is no net consumption of Succinyl-CoA. Succinyl-CoA is first converted to malate, and then to pyruvate where it is then transported to the matrix to enter the citric acid cycle.
Another fate of succinyl-CoA is porphyrin synthesis, where succinyl-CoA and glycine are combined by ALA synthase to form δ-aminolevulinic acid (dALA). This process is the committed step in the biosynthesis of porfobilinogen and thus hemoglobin.
Succinyl CoA can be formed from methylmalonyl CoA through the utilization of deoxyadenosyl-B12 (deoxyadenosylcobalamin) by the enzyme methylmalonyl-CoA mutase. This reaction, which requires vitamin B12 as a cofactor, is important in the catabolism of some branched-chain amino acids as well as odd-chain fatty acids.
Interactive pathway map
Click on genes, proteins and metabolites below to link to respective articles. [§ 1]