Mitochondrial fatty acid beta-oxidation pathway enzymes (mFAO enzymes)

Mitochondrial fatty acid oxidation (mFAO) enzymes constitute a critical metabolic pathway responsible for the breakdown of long-chain fatty acids into acetyl-CoA, which then enters the tricarboxylic acid (TCA) cycle to generate ATP (UniProt, 2024). This process involves several key stages: the carnitine shuttle (mediated by CPT1 and CPT2), the four-step beta-oxidation cycle (dehydrogenation, hydration, oxidation, and thiolysis), and the electron transfer flavoprotein (ETF) system (PubMed, 2022). In clinical practice, these enzymes are targeted to shift cardiac metabolism from fatty acids to glucose, which requires less oxygen per mole of ATP produced, thereby benefiting patients with stable angina or heart failure (StatPearls, 2023). For example, inhibitors like trimetazidine target the 3-ketoacyl-CoA thiolase enzyme to optimize myocardial energy use (PubMed, 2021). Additionally, inherited deficiencies in enzymes like Medium-chain acyl-CoA dehydrogenase (MCAD) lead to severe metabolic crises characterized by hypoketotic hypoglycemia (NIH GARD, 2024). Over-reliance on mFAO is also observed in certain cancers, making these enzymes potential targets for metabolic reprogramming in oncology (PubMed, 2023). Therapeutic modulation of this pathway must be carefully managed due to risks of hepatotoxicity and systemic metabolic imbalance associated with certain inhibitors like etomoxir (PubMed, 2020).

Other names

Mitochondrial fatty acid oxidation (mFAO) systemBeta-oxidation enzymesFatty acid oxidation (FAO) complexCarnitine palmitoyltransferase systemAcyl-CoA dehydrogenase familyMitochondrial trifunctional protein

Inhibition of specific enzymes within the beta-oxidation cycle, such as long-chain 3-ketoacyl-CoA thiolase (3-KAT) or carnitine palmitoyltransferase 1 (CPT1), to shift cellular metabolism from fatty acid oxidation to glucose oxidation, thereby improving oxygen efficiency in ischemic tissues (StatPearls, 2023; PubMed, 2021).