Purification and characterization of peroxisomal L-pipecolic acid oxidase from monkey liver.
L-Pipecolic acid oxidase has been purified to near homogeneity from Rhesus monkey liver. The protein, a yellow monomer, has a molecular weight of 46,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and a pI of 8.9. It contains a covalently bound flavin with absorption maxima at 457 and 383 nm and a shoulder at 480 nm. The purified enzyme is most reactive toward L-pipecolic acid, with lesser reactivities toward L-proline and sarcosine. The enzyme has no significant reactivity toward the D-enantiomer of pipecolic acid or toward any other amino acid tested. Benzoic acid is a competitive inhibitor of the enzyme with a Ki of 750 microM. The Km of the purified enzyme is 3.7 mM for L-pipecolic acid. With less purified preparations, the reaction product is alpha-aminodipic acid. The purified enzyme, however, produces an intermediate which reacts with ortho-aminobenzaldehyde to form an alpha-aminoadipic acid semialdehyde adduct. Thus, the formation of alpha-aminoadipic acid requires at least two enzymes.
Mihalik
S J
SJ
Kennedy Institute for Handicapped Children, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
McGuinness
M
M
Watkins
P A
PA
D000818:Animals; D015153:Blotting, Western; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D007525:Isoelectric Focusing; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008253:Macaca mulatta; D008830:Microbodies / Q000201:enzymology*; D008970:Molecular Weight; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D013056:Spectrophotometry, Ultraviolet
D000587:Oxidoreductases Acting on CH-NH Group Donors; C032771:L-pipecolate dehydrogenase