Functional expression of two forms of rat acyl-CoA oxidase and their substrate specificities.

Using the reverse transcription of RNA followed by the polymerase chain reaction, we cloned the cDNAs for the rat acyl-CoA oxidases I and II, which are produced by alternative splicing from a single gene, and developed a system for their expression in Escherichia coli. The homogeneous preparations of these enzymes, without proteolytic procession, showed oxidase activity with acyl-CoAs having various acyl-chain lengths. The two types of the enzyme exhibited different substrate specificities with respect to the acyl-chain length, acyl-CoA oxidase I showing the optimum activity at shorter chain-length relative to acyl-CoA oxidase II.