Peroxisomal D3, D2-Enoyl Coenzyme A Isomerase (PECI)

PECI is an auxiliary enzyme that catalyzes an isomerization step required for the beta-oxidation of unsaturated fatty acids.Human PECI contains 2 putative start codons, while mouse Peci contains only the second start codon. Both contain a C-terminal peroxisomal targeting signal. Northern blot analysis detected a 1.5-kb transcript in all human tissues examined. Highest expression was detected in heart, skeletal muscle, and liver. Western blot analysis of fibroblasts showed that endogenous PECI migrated with an apparent molecular mass of 39 kD. PECI partitioned with peroxisomal markers following fractionation of hepatocellular carcinoma cells, and immunofluorescence microscopy of differentially permeabilized fibroblasts indicated that PECI is a peroxisomal matrix protein.