CPT-2

Carnitine palmitoyltransferase 2 (CPT-2) is a ubiquitously expressed mitochondrial enzyme that catalyzes the conversion of long-chain acylcarnitines to acyl-CoA within mitochondria, thereby enabling mitochondrial β-oxidation of long-chain fatty acids and cellular energy production^[1][2]. CPT-2 functions as a core component of the carnitine shuttle, acting downstream of CPT1 to utilize acylcarnitines generated at the outer mitochondrial membrane and support fatty acid flux into oxidative pathways^[1][3]. Mechanistically, mitochondrial fatty acid oxidation depends on the coordinated activities of CPT1 and CPT-2, with CPT1 generating acylcarnitines and CPT-2 converting these intermediates back to metabolically active acyl-CoA species^[3]. Deficiency of CPT-2 disrupts long-chain fatty acid oxidation and causes CPT II deficiency, a metabolic disorder characterized by impaired utilization of fatty acids as an energy source, particularly during fasting or increased energy demand^[2][4]. Disease manifestations range from severe neonatal and infantile forms to the more common myopathic phenotype associated with recurrent muscle symptoms and metabolic crises^[4][5]. Compared with related CPT1 isoforms, which display tissue-specific expression patterns including liver, muscle, and brain variants, CPT-2 is ubiquitously expressed and serves as the common downstream mitochondrial enzyme of the carnitine transport system^[1][5]. Experimental studies using Cpt2-deficient models demonstrate that loss of CPT-2 abolishes mitochondrial oxidation of non-esterified fatty acids, making CPT-2 a valuable target for investigating fatty acid metabolism and mitochondrial dysfunction^[3].