Table 1.
Molecular weights and functions of the 2-oxo-acid dehydrogenase complexes
| Enzymes | MW (kDa) | Function |
|---|---|---|
| Pyruvate dehydrogenase complexes | (PDC) | |
| E1a decarboxylase | 41 | Decarboxylates pyruvate with thiamine pyrophosphate (TTP) as a co-factor |
| E1b decarboxylase | 36 | Decarboxylates pyruvate with TTP as a co-factor |
| E2 acetyltransferase | 74 | Transfers acetyl group from E1 to coenzyme A (CoA) |
| E3 lipoamide dehydrogenase | 55 | Regenerates disulphide of E2 by oxidation of lipoic acid |
| E3 binding protein (protein X) | 56 | Anchoring E2 to the E2 core of pyruvate dehydrogenase complex |
| 2-oxoglutarate dehydrogenase complex | (OGDC) | |
| E1 oxoglutarate dehydrogenase | 113 | Decarboxylates a-ketoglutarate with TTP as a co-factor |
| E2 succinyl transferase | 48 | Transfers succinyl group from E2 to CoA |
| E3 lipoamide dehydrogenase | 55 | Regenerates disulphide of E2 by oxidation of lipoic acid |
| Branched-chain 2-oxo-acid dehydrogenase complex | (BCOADC) | |
| E1a decarboxylase | 46 | Decarboxylates a-keto acids |
| E1b decarboxylase | 38 | Derived from leucine, isoleucine, and valine with TTP as a co-factor |
| E2 acyltransferase | 52 | Transfers acyl group from E1 to CoA |
| E3 lipoamide dehydrogenase | 55 | Regenerates disulphide of E2 by oxidation of lipoic acid |