Hamster Hepatic Nuclear Mixed-Function Amine Oxidase: Location and Specific Activity

Nuclei isolated from hamster liver contain activities characteristic of the mixed-function amine oxidase. The enzyme present in nuclei, like the microsomal monooxygenase, catalyzes the oxygenation of both nitrogen and sulfur compound. Activity per milligram protein of isolated nuclei is 12-14% that of microsomes. The hamster liver monooxygenase cross-reacts with antibodies raised in rabbits to the homogeneous pig liver microsomal mixed-function amine oxidase, and isolated nuclei stained with fluorescent labeled anti-body indicate that the monooxygenase is largely concentrated in the nuclear envelope.