Preparation of aldehyde oxidase in its native and deflavo forms. Comparison of spectroscopic and catalytic properties.

Aldehyde oxidase (EC 1.2.3.1) has been purified by a modification of a previously reported procedure and the FAD prosthetic group has been removed by treatment with calcium chloride and calcium acetate. The deflavo enzyme so obtained is devoid of Wmethylnicotinamide oxygen reductase activity but can be reconstituted by a short incubation with FAD. The different activities of native and deflavo enzymes using oxygen, cytochrome c, potassium ferricyanide, nitro blue tetrazolium, dichlorophenolindophenol, and FAD as electron acceptors and W-methylnicotinamide as substrate are compared.