OGDH

OGDH

2-oxoglutarate dehydrogenase (OGDH) is an important enzyme in the citric acid cycle (also known as the Krebs cycle or TCA cycle). It catalyzes the conversion of 2-oxoglutarate (also known as alpha-ketoglutarate) into succinyl-CoA and carbon dioxide. This reaction is a key step in the metabolic pathway that generates adenosine triphosphate (ATP) through the oxidation of acetyl-CoA.

Function

OGDH is a component of the 2-oxoglutarate dehydrogenase complex, which is a multi-enzyme complex that also includes dihydrolipoamide succinyltransferase and dihydrolipoamide dehydrogenase. This complex is responsible for the decarboxylation of 2-oxoglutarate, a critical step in the citric acid cycle.

Structure

The enzyme is a large, multi-subunit complex that requires several cofactors for its activity, including thiamine pyrophosphate (TPP), lipoic acid, coenzyme A (CoA), FAD, and NAD+.

Clinical significance

Mutations or deficiencies in OGDH can lead to metabolic disorders and have been associated with neurological diseases. The enzyme's activity is crucial for maintaining normal cellular energy levels, and its dysfunction can result in mitochondrial diseases.

Regulation

OGDH activity is regulated by the availability of its substrates and cofactors, as well as by feedback inhibition from its products, such as NADH and succinyl-CoA.

See also

• Citric acid cycle
• Mitochondrial diseases
• Enzyme regulation

External links

• OGDH on WikiMD

Acetyl-CoA + H2O	Oxaloacetate NADH +H+ NAD+ Malate   H2O Fumarate FADH2 FAD Succinate CoA + ATP (GTP) Pi + ADP (GDP) Succinyl-CoA
			NADH + H+ + CO2
CoA			NAD+
	Citrate   H2O cis-Aconitate H2O   Isocitrate NAD(P)+ NAD(P)H +  H+ Oxalosuccinate   CO2 2-oxoglutarate