Alpha Oxidation- Definition, Location, Pathway, Steps, Significance


Alpha oxidation is a type of fatty acid oxidation that occurs in peroxisomes. It involves the removal of one carbon atom from the alpha position of the fatty acid chain, which is adjacent to the carboxyl group. Alpha oxidation is different from beta oxidation, which removes two carbon atoms from the beta position of the fatty acid chain, which is next to the alpha position.

Alpha oxidation is a specialized pathway that occurs in certain fatty acids that have a methyl group at the beta position. This methyl group prevents beta oxidation from taking place, as it blocks the access of the enzyme acyl-CoA dehydrogenase. Therefore, alpha oxidation is necessary to remove the methyl group and allow beta oxidation to proceed.

Alpha oxidation does not produce any ATP or NADH, unlike beta oxidation. Instead, it produces CO2 and formyl-CoA as byproducts. The main purpose of alpha oxidation is to catabolize branched-chain fatty acids and produce cerebronic acid, which is a precursor for cerebrosides and sulfatides. These are important components of the myelin sheath that surrounds nerve cells.

Alpha oxidation is also involved in the synthesis of hydroxy fatty acids, which can be further oxidized and decarboxylated to produce shorter fatty acids. This process can convert odd-chain fatty acids into even-chain fatty acids, which can undergo beta oxidation more easily.

Alpha oxidation is a rare but essential metabolic pathway that plays a role in the maintenance of nervous system function and lipid homeostasis. A defect in alpha oxidation can lead to Refsum`s disease, a genetic disorder that causes neurological and visual impairments.