Subcellular distribution of coenzyme A: evidence for a separate coenzyme A pool in peroxisomes

Summary Subcellular fractions enriched in peroxisomes, that were prepared by differential centrifugation, contained more free and total (free plus esterified) CoA than could be accounted for by mitochondrial contamination. Separation of peroxisomes and mitochondria by isopycnic centrifugation of fractions enriched in peroxisomes resulted in a bimodal distribution of free and total CoA in which both peak fractions coincided with the fractions that contained most of the peroxisomal and mitochondrial marker enzyme activities respectively. These results indicate that peroxisomes have a separate CoA-pool. This CoA appears to be available for the thiolase reaction during peroxisomal β-oxidation of fatty acids but not for the activation of fatty acids by the peroxisomal acyl-CoA synthetase.