Oxoglutarate dehydrogenase complex

Oxoglutarate dehydrogenase complex

The oxoglutarate dehydrogenase complex (OGDC) or α-ketoglutarate dehydrogenase complex is an enzyme complex, most commonly known for its role in the citric acid cycle.



Much like pyruvate dehydrogenase complex (PDC), this enzyme forms a complex composed of three components:

Unit EC number Name Gene Coenzyme
E1 EC oxoglutarate dehydrogenase OGDH thiamine pyrophosphate
E2 EC dihydrolipoyl succinyltransferase DLST lipoic acid
E3 EC dihydrolipoyl dehydrogenase DLD FAD

In fact, three classes of these multienzyme complexes have been characterized, one specific for pyruvate, a second specific for 2-oxoglutarate, and a third specific for branched-chain α-keto acids.


Metabolic pathways

This enzyme participates in three different pathways:

Kinetic properties

The following values are from Azotobacter vinelandii (1):

  • KM: 0.14 ± 0.04 mM
  • Vmax : 9 ± 3 μmol.min-1.mg-1

Citric acid cycle


The reaction catalyzed by this enzyme in the citric acid cycle is:

α-ketoglutarate + NAD+ + CoA → Succinyl CoA + CO2 + NADH
Oxoglutarate dehydrogenase (α-Ketoglutarate dehydrogenase)

This reaction proceeds in three steps:

  • decarboxylation of α-ketoglutarate,
  • reduction of NAD+ to NADH,
  • and subsequent transfer to CoA, which forms the end product, succinyl CoA.

ΔG°' for this reaction is -7.2 kcal mol-1. The energy needed for this oxidation is conserved in the formation of a thioester bond of succinyl CoA.


Oxoglutarate dehydrogenase is a key control point in the citric acid cycle. It is inhibited by its products, succinyl CoA and NADH. A high energy charge in the cell will also be inhibitive. ADP and calcium ions are allosteric activators of the enzyme.


2-Oxo-glutarate dehydrogrenase is an autoantigen recognized in primary biliary cirrhosis, a form of acute liver failure. These antibodies appear to recognize oxidized protein that has resulted from inflammatory immune responses. Some of these inflammatory responses are explained by gluten sensitivity.[1] Other mitochondrial autoantigens include pyruvate dehydrogenase and branched-chain alpha-keto acid dehydrogenase complex, which are antigens recognized by anti-mitochondrial antibodies. Activity of the 2-oxoglutarate dehydrogenase complex is decreased in many neurodegenerative diseases.


  1. ^ Leung PS, Rossaro L, Davis PA, et al. (2007). "Antimitochondrial antibodies in acute liver failure: Implications for primary biliary cirrhosis". Hepatology 46: 1436. doi:10.1002/hep.21828. PMID 17657817. 
  1. Bunik V, Westphal AH, de Kok A: Kinetic properties of the 2-oxoglutarate dehydrogenase complex from Azotobacter vinelandii evidence for the formation of a precatalytic complex with 2-oxoglutarate. Eur J Biochem 2000; 267(12): 3583-91. PMID 10848975.
  2. Bunik VI, Strumilo S: "Regulation of Catalysis Within Cellular Network: Metabolic and Signaling Implications of the 2-Oxoglutarate Oxidative Decarboxylation." Current Chemical Biology, 2009, 3: 279-290
  3. Bunik VI, Fernie AR: "Metabolic control exerted by the 2-oxoglutarate dehydrogenase reaction: a cross-kingdom comparison of the crossroad between energy production and nitrogen assimilation." Biochem. J. 2009, 422: 405–421
  4. L. Trofimova, M. Lovat, A. Groznaya, E. Efimova, T. Dunaeva, M. Maslova, A. Graf, and V. Bunik: "Behavioral Impact of the Regulation of the Brain 2-Oxoglutarate Dehydrogenase Complex by Synthetic Phosphonate Analog of 2-Oxoglutarate: Implications into the Role of the Complex in Neurodegenerative Diseases." International Journal of Alzheimer Disease 2010; Volume 2010, Article ID 749061, 8 pages, doi:10.4061/2010/749061, http://www.sage-hindawi.com/journals/ijad/2010/749061.html

External links

Wikimedia Foundation. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • Oxoglutarate dehydrogenase — Protbox Name=2 oxoglutarate dehydrogenase E1 component (α Ketoglutarate dehydrogenase) Photo= Caption= HGNCid = 8124 Symbol = OGDH AltSymbols = Names= Alpha ketoglutarate dehydrogenase Chromosome = 7 Arm = p Band = 13 LocusSupplementaryData = p11 …   Wikipedia

  • Pyruvate dehydrogenase complex — (PDC) is a complex of three enzymes that transform pyruvate into acetyl CoA by a process called pyruvate decarboxylation. Acetyl CoA may then be used in the citric acid cycle to carry out cellular respiration, and this complex links the… …   Wikipedia

  • Branched-chain alpha-keto acid dehydrogenase complex — protein Name=2 oxoisovalerate dehydrogenase (lipoamide) caption= width= HGNCid=8523 Symbol=OVD1A AltSymbols= EntrezGene=5014 OMIM= RefSeq= UniProt= PDB= ECnumber= Chromosome= Arm= Band= LocusSupplementaryData=The branched chain α keto acid …   Wikipedia

  • α-ketoglutarate dehydrogenase complex — a multienzyme complex consisting of at least three distinct enzymes: oxoglutarate dehydrogenase (succinyl transferring) [EC] (more commonly called α ketoglutarate dehydrogenase), dihydrolipoyllysine residue succinyltransferase [EC… …   Medical dictionary

  • Dihydrolipoamide dehydrogenase — PDB rendering based on 1zy8 …   Wikipedia

  • Pyruvate dehydrogenase — Crystallographic structure of pyruvate dehydrogenase (PDH). PH is a six domain dimer with α (blue), α’ (yellow), β (red), and β’ (teal) regions denoted by the different colors. Thiamine pyrophosphate (TPP) is shown in grey ball and stick form,… …   Wikipedia

  • Succinate dehydrogenase — (ubiquinone) Subunits: SdhA, SdhB, SdhC and SdhD Identifiers EC number …   Wikipedia

  • NADH dehydrogenase — Structure of NADH dehydrogenase Identifiers EC number …   Wikipedia

  • Malate dehydrogenase — Structure of the protein with attached sugars Identifiers EC number …   Wikipedia

  • Dihydroorotate dehydrogenase — Dihydroorotate oxidase Identifiers EC number CAS number 9029 03 2 …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”