Docosahexaenoic Acid Synthesis in Peroxisomal Disorders, Studies In Vitro and In Vivo

and colleagues, who suggested a mitochondrial role in 22:6n-3 (12-14). Both mitochondria and peroxisomes perform fatty acid β-oxidation and release acetyl-CoA. The process of twocarbon chain shortening is similar in both organelles containing dehydrogenation/oxidation, hydration, dehydrogenation, and thiolytic cleavage (Fig. 1). The first step of mitochondrial fatty acid β-oxidation is catalyzed by acyl-CoA dehydrogenases, a group of enzymes with distinct chain-length specificity for acyl-CoA (15). Two peroxisomal fatty acid β-oxidation pathways have been proposed, including straight-chain and branched-chain fatty acid β-oxidation pathways, for the oxidation of very-long-chain fatty acids (e.g., 26:0) and 2-methyl-branched fatty acids (pristanic acid), respectively (16).