Stereochemistry of Peroxisomal and Mitochondrial β‐oxidation of α‐methylacyl‐CoAs

Abstract

The stereochemistry of β-oxidation of α-methyl-branched fatty acids was analyzed, in rat liver and in human cells, with (2R)- and (2S)-2-methyltetradecanoic acid as model substrates. In rat liver, formation of the α,β-unsaturated compound was found to be concentrated in mitochondria while in human cells, this activity co-distributed mainly with peroxisomal marker enzymes. In both cases, the dehydrogenating enzymes were absolutely specific for the (2S)-enantiomer. In human liver, activation was some three times faster with the (2R)- than with the (25)-isomer while in rat liver both were activated at about the same rate.