VIII. Fatty Acid Activation and Transport into the
The fatty acyl group is transported into the mitochondrial matrix, where it undergoes beta-oxidation.
In the intermembrane space of the mitochondria, fatty acyl CoA reacts with carnitine in a reaction catalyzed by carnitine acyltransferase I (CAT-I), yielding CoA and fatty acyl carnitine. The resulting fatty acyl carnitine crosses the inner mitochondrial membrane.
- CAT-I is associated with the inner leaflet of the outer
- In liver the CAT-I reaction is rate-limiting; the enzyme is
allosterically inhibited by malonyl CoA. Malonyl CoA
concentration would be high during fatty acid synthesis. Inhibition of CAT-I by malonyl CoA prevents simultaneous synthesis and degradation of fatty acids.