Pipecolic Acid Oxidase (PIPOX)

L-Pipecolic acid oxidase activity is deficient in patients with peroxisome biogenesis disorders (PBDs). The cDNA was cloned with the use of a reverse genetics approach based on the amino acid sequence obtained from purified L-pipecolic acid oxidase from monkey.

The complete cDNA, obtained by conventional library screening and 5' rapid amplification of cDNA ends, encompassed an open reading frame of 1170 bases, translating to a 390-residue protein. The recombinant enzyme oxidized both L-pipecolic acid and sarcosine. However, PBD patients who lack the enzyme activity accumulate only L-pipecolic acid, suggesting that in humans in vivo, this enzyme is involved mainly in the degradation of L-pipecolic acid.