regulation
Last reviewed 01/2018
Regulation of the tricarboxylic acid cycle occurs at several key sites:
- citrate synthase
- isocitrate dehydrogenase
- oxoglutarate dehydrogenase
The key themes are:
- activation in proportion to the quantity of substrate amassing
- inhibition in proportion to the quantity of product accumulating
- activation in proportion to depletion of ATP energy reserves
- activation in proportion to release of calcium in skeletal muscle
Occasionally, the absence of co-factors, such as FAD for succinate dehydrogenase, will make other equilibrium reactions within the TCA cycle into rate-limiting steps.
The activity of pyruvate dehydrogenase indirectly regulates flux through the TCA cycle by determining the rate of provision of acetyl-CoA to citrate synthase.
regulation (isocitrate dehydrogenase)
regulation (oxoglutarate dehydrogenase)