Functions and organization of peroxisomal beta-oxidation

In eukaryotic microorganisms such as yeasts and fungi, peroxisomes are the sole site of beta-oxidation. Also in plants, peroxisomes are capable of beta-oxidizing fatty acids. Whether plant mitochondria are involved in fatty acid catabolism remains controversial. A few reports indicate, however, that plant mitochondria contain a functional beta-oxidation system, but its capacity seems to be 50- to 200-fold lower than that of peroxisomes.(1) In mammals, both peroxisomes and mitochondria are actively engaged in the beta-oxidation of fatty acids and other lipophilic carboxylates. This paper deals with peroxisomal beta-oxidation in mammals. Since peroxisomal beta-oxidation has been best characterized in rat and man, our description will be limited mainly to these two species.