Molecular cloning and functional expression of a human peroxisomal acyl-coenzyme A oxidase

cDNA encoding the human peroxisomal acyl-coenzyme A oxidase (AOX) was cloned and sequenced. The longest cDNA insert isolated has 3083 bases and encodes the entire protein of 661-amino acids, including the carboxyl-terminal sequence (Ser-Lys-Leu) known as a minimal peroxisome-targeting signal. At the amino acid level, the significantly high homology (89%) to rat AOX was found. In the cDNA-expression experiment, significant amount of AOX was accumulated in human skin fibroblast and the expressed AOX was catalytically active, while only a limited amount was found in Zellweger syndrome patient's fibroblast not having normal peroxisomes.