| Research Abstract |
Neither xanthine oxidase, xanthine dehydrogenase, lipoamide dehydrogenase, NADPH-cytochrome c reductase nor NADH-cytochrome b reductase by itself exhibited reductase activities towards N-oxide and sulfoxide ^5 compounds even in the presence of its electron donor. However, when one of these flavin enzymes and its electron donor were combined with aldehyde oxidase, significant N-oxide and sulfoxide reductase activities were observed in either case. This fact indicated that aldehyde oxidase is capable of coupling with such flavin enzymes as described above, forming new electron transfer systems in which N-oxide and sulfoxide compunds function as final electron acceptors.
Rabbit live aldehyde oxidase has been found to utilize as electron acceptors aromatic hydroxamic acids, N-aryl aliphatic hydroxamic acids and oximes, as well as N-oxide and sulfoxide compounds. In the present study, furthermore, aldehyde oxidase was purified successfully from guinea pig liver and bovine ciliary body. In either case, the purified enzyme was homogeneous by the criterion of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS- PAGE). Its molecular weight was estimated to be about 300,000 by gel filtration and to be about 150,000 by SDS-PAGE.
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