Peroxisomal beta-oxidation: Enzymology and molecular biology

The three fatty acid beta-oxidation systems are mitochondrial, peroxisomal, and bacterial. The former two are present in animal cells, while plant cells have a peroxisomal system and bacteria have their own distinct system. The comparative enzymology and molecular biology of peroxisomal and mitochondrial systems are summarized in this report. The beta-oxidation hypothesis for fatty acid oxidation was proposed many years ago. Enzymological studies were begun and localization in the mitochondria was established in the 1950s. The presence of a fatty acid beta-oxidation system outside the mitochondrial compartment was first noted in glyoxysomes.(1) A very similar system was found in rat liver peroxisomes by Lazarow and de Duve in 1976.(2) This finding attracted attention because it was the first report describing the presence of a metabolic sequence in peroxisomes in higher animals. Enzymological studies indicated that this system consists of unique enzymes differing from mitochondrial enzymes.