Energy metabolism | 2-Oxoglutarate Dehydrogenase Complex
Abstract
2-Oxoglutarate dehydrogenase (ogdh gene) is an ubiquitous enzyme with additional isoenzymes (ogdhl and dhtkd1 genes) characterized in animals. Using thiamine (vitamin B1) diphosphate, the isoenzymes catalyze oxidative decarboxylation of 2-oxoglutarate or 2-oxoadipate. The coupled generation of succinyl- or glutaryl-CoA and NADH requires self-assembled multienzyme complexes. The complex core is formed by dihydrolipoyl succinyltransferase (dlst gene), binding multiple copies of 2-oxoglutarate dehydrogenase and dihydrolipoamide dehydrogenase (dldh gene). The components stoichiometry depends on the complex sources and/or isolation conditions. Components of the 2-oxoglutarate dehydrogenase complex also catalyze carboligase reaction or reaction with molecular oxygen, which are of potential physiological significance.