Function
Carnitine palmitoyltransferase (CPT I and CPT II) are involved in the transport of long-chain fatty acids into the mitochondria where they are oxidized. Fatty acids form a conjugate with CoA before being oxidized in the mitochondria. However, the CoA-long-chain fatty acid conjugates can not diffuse into the mitochondria.
- CPT I is a membrane protein which substitutes the CoA in the long-chain fatty acids by carnitine. After entering the mitochondria.
- CPT II exchanges the carnitine by CoA, enabling the oxidation of the long-chain fatty acids.
Disease
CPT I deficiency prevents the body from using certain fats for energy, particularly during fasting. It is associated with encephalopathy, seizures and unexpected infancy death. CPT I is important in fatty acid disorders like diabetes.
Structural highlights
CPT I contains an extra ca. 160 amino acids domain at its N terminal. Substrate analog interacts with CPT II 2rcu in a large tunnel with its hydrophilic head group situated at the tunnel center and the alkyl part occupying the hydrophobic part of the tunnel.
3D structures of carnitine palmitoyltransferase
Updated on 22-November-2015
2h4t, 2fyo, 2deb – rCPT II – rat
2fw3 - rCPT II + antidiabetic drug
2rcu – rCPT II + substrate analog
4ep9, 4eph, 4eyw - rCPT II + inhibitor
2le3 – hCPT I regulatory domain – human - NMR
2m76 - hCPT I regulatory domain – NMR
