Abstract
Highly sensitive and rapid assay procedures for human mitochondrial the pyruvate dehydrogenase (PDH) complex, the 2-oxoglutarate dehydrogenase (OGDH) complex and their 5 component enzymes were established for use with crude tissue extracts, and their enzymatic activities were determined. Overall reaction activities of the PDH and OGDH complexes were very high, in order of heart>abdominal skeletal muscle>kidney. Full-length cDNA encoding the precursor of theporcine dihydrolipoamide acetyltransferase (E2p) subunit was isolated and characterized. It contained an open reading frame encoding a leader peptide (86 residues) and a mature enzyme protein (561 residues, Mr=59, 699). The reduced enzyme protein showed 91% identity with the human enzyme. All genes encoding the component enzymes of the 2 human complexes were expressed in a variety of organs, but most strongly in heart and skeletal muscle (abdominal muscle) in a similar order as found for their enzymatic activities.
