AcylcarnitinMolekül

Acylcarnitine Molekül

Acylcarnitine molekül refers to a class of molecules characterized by the presence of an acyl group esterified to the hydroxyl group of carnitine. Carnitine itself is a quaternary ammonium compound synthesized in the liver and kidneys, playing a crucial role in cellular energy metabolism. The acyl group attached to carnitine can vary, typically being a fatty acid residue of varying chain length, such as acetyl, propionyl, or octanoyl groups.

The primary function of acylcarnitines is to facilitate the transport of fatty acids across the inner mitochondrial membrane. Fatty acids, particularly long-chain ones, cannot freely diffuse into the mitochondria. Carnitine palmitoyltransferase I (CPT I) on the outer mitochondrial membrane attaches the fatty acid to carnitine, forming an acylcarnitine. This acylcarnitine can then be transported across the inner mitochondrial membrane by the carnitine-acylcarnitine translocase (CACT). Once inside the mitochondrial matrix, the acyl group is transferred back to coenzyme A (CoA) by carnitine palmitoyltransferase II (CPT II), and the fatty acid is then available for beta-oxidation, the process that generates ATP.

Acylcarnitines are also important biomarkers. Elevated levels of specific acylcarnitines in biological fluids like blood or urine can indicate metabolic disorders, particularly defects in fatty acid oxidation or amino acid metabolism. For example, acylcarnitine profiles are routinely analyzed in newborn screening programs to detect conditions such as medium-chain acyl-CoA dehydrogenase (MCAD) deficiency. Monitoring acylcarnitine levels can also be relevant in conditions like diabetes and certain liver diseases.