Fatty Acid Activation Fatty acid HSCoA+ atP fatty acyl-CoA AMP PPi Catalyzed enzyme is acyl CoA synthase(also called fatty acid thiokinase)
Fatty Acid Activation • Fatty acid + HSCoA + ATP fatty acyl-CoA + AMP + PPi • Catalyzed enzyme is acyl CoA synthase (also called fatty acid thiokinase)
Fatty acid activation O-P-0-P-0- Adenosine ATP R-C Fatty acid fatty acyl-CoA synthetase O-P-0- Adenosine R Fatty acyl-adenylate (enzyme-bound) Pyrophosphate COA-SH fatty aeyl-CaA norganIc synthetase AMP pyropE R-C Fatty acvI-CoA S-COA △G=-33.4kd/mol △G°=0.9kJ/mol (for the two-step process)
Fatty acid activation
Transport into mitochondria Small-and medium-chain acyl CoA molecules (up to 10 carbon atoms)are readily able to cross the inner mitochondrial membrane by diffusion The long acyl CoA is transported into the mitochondria as carnitine肉碱 derivatives by carnitine /acyl carnitine translocase移位酶
Transport into mitochondria • Small- and medium-chain acyl CoA molecules (up to 10 carbon atoms) are readily able to cross the inner mitochondrial membrane by diffusion. • The long acyl CoA is transported into the mitochondria as carnitine 肉碱 derivatives by carnitine / acyl carnitine translocase 移位酶
Structure of carnitine CH: CHy-N-CH9-CH-CH2-COO CH OH Carnitine
Structure of carnitine
Fatty acid entry into mitochondria via the acyl-carntinelcarntine transporter Intermembrane Carnitine acyltransferase Il sCaA∠ Carnitine Carnitine S-CoA Carnitine R-C CoA-SH CoA-SH Carnitine Carnitine acyltransferase I Matr
Fatty acid entry into mitochondria via the acyl-carntine/carntine transporter