Succinyl-CoA

Structural formula
General
Surname	Succinyl-CoA
Molecular formula	C 25 H 40 N 7 O 19 P 3 S
External identifiers / databases
CAS number 604-98-8 EC number 210-079-5 ECHA InfoCard 100.009.163 PubChem 92133 ChemSpider 83179 DrugBank DB03699 Wikidata Q419560
properties
Molar mass	867.61 g mol −1
safety instructions
GHS hazard labeling no classification available
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Succinyl-coenzyme A (abbreviated succinyl-CoA ) is a thioester of succinic acid with coenzyme A . In biochemistry , it is also used to describe the anion . Succinyl-CoA occurs as an intermediate product in various metabolic processes .

Meaning in the citric acid cycle

Succinyl-CoA is formed in the citrate cycle from α-ketoglutarate by oxidative decarboxylation and formation of a thioester with coenzyme A. The multi-stage reaction is catalyzed by the α-ketoglutarate dehydrogenase complex . One molecule of CO ₂ and one molecule of NADH are formed for each converted molecule of α-ketoglutarate . In the further course of the citric acid cycle, succinyl-CoA is cleaved into succinate and coenzyme A by succinyl-CoA synthetase . It also creates a molecule of an energy-rich phosphate compound, which is either GTP or ATP .

More reactions

• Succinyl-CoA is also produced from propionyl-CoA with the participation of the enzymes propionyl-CoA carboxylase , methylmalonyl-CoA epimerase and methylmalonyl-CoA mutase . This implementation is one of the anaplerotic reactions . Succinyl-CoA is the entry point into the citric acid cycle for parts of the carbon structure of the amino acids isoleucine , valine , methionine and threonine .

• Succinyl-CoA is one of the starting materials in the synthesis of the porphyrins and is therefore removed from the citric acid cycle ( cataplerotic reaction ). Succinyl-CoA reacts with glycine to form δ-aminolevulinate . The reaction is catalyzed by the δ-aminolevulinate synthase . Succinyl-CoA is therefore a basic substance for building up the heme complex , which is contained in the red blood pigment hemoglobin , among other things .

• The utilization of the ketone body acetoacetate is initiated by succinyl-CoA releasing coenzyme A to acetoacetate, whereby acetoacetyl-CoA and succinate are formed. The exchange is catalyzed by 3-keto acid CoA transferase (SCOT).

• There is evidence that succinyl-CoA is also the end product of the β-oxidation of dicarboxylic acids in the peroxisomes of the kidney and liver . Succinyl- CoA is cleaved by succinyl-CoA thioesterase (ACOT4) into succinate and CoA. Dicarboxylic acids are formed by ω-oxidation of fatty acids .

Individual evidence

1. ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
2. ↑ Entry EC  6.2.1.4 in the BRENDA enzyme database
3. ↑ Entry EC  6.2.1.5 in the BRENDA enzyme database
4. ↑ JM Berg, JL Tymoczko, L. Stryer: Biochemistry. 6th edition. Spectrum Academic Publishing House, Elsevier GmbH, Munich 2007; P. 542f; ISBN 978-3-8274-1800-5
5. ↑ Entry EC  5.1.99.1 in the BRENDA enzyme database
6. ↑ JM Berg, JL Tymoczko, L. Stryer: Biochemistry. 6th edition. Spectrum Academic Publishing House, Elsevier GmbH, Munich 2007; Pp. 697f, 741f, 744f; ISBN 978-3-8274-1800-5
7. ↑ JM Berg, JL Tymoczko, L. Stryer: Biochemistry. 6th edition. Spectrum Academic Publishing House, Elsevier GmbH, Munich 2007; Pp. 550f, 782ff; ISBN 978-3-8274-1800-5
8. ↑ JM Berg, JL Tymoczko, L. Stryer: Biochemistry. 6th edition. Spectrum Academic Publishing House, Elsevier GmbH, Munich 2007; P. 702f; ISBN 978-3-8274-1800-5
9. ^ MA Westin, MC Hunt, SE Alexson: The identification of a succinyl-CoA thioesterase suggests a novel pathway for succinate production in peroxisomes. In: J. Biol. Chem. 280 (46); Nov 2005: S. 38125-32 PMID 16141203 (full text)

Web links

Wikibooks: Biochemistry and Pathobiochemistry: Citric Acid Cycle  - Learning and Teaching Materials

Wikibooks: Biochemistry and Pathobiochemistry: Degradation of Propionyl-CoA  - Learning and Teaching Materials

Wikibooks: Biochemistry and Pathobiochemistry: Porphyrin Biosynthesis  - Learning and Teaching Materials