Subcellular localization of monoamine oxidase in bovine thalamus tissue using immunoferritin conjugates.

A combination of discontinuous sucrose gradient analysis and polyacrylamide electrophoresis was used to isolate one of the multiple forms of monoamine oxidase (MAO) from bovine thalamus. This substance (the principle form and the most anodic of the five MAO forms observed) was used as a basis for an immunoferritin-electron microscope approach to determine the subcellular localization of MAO in thalamus. This form of MAO, as well as antigenically related forms, was found to reside mainly on the outer mitochondrial membrane. In addition, the action of SDS on solubilization and interconversion of MAO forms was studied and found to be dependent on the concentration and time of reaction of SDS with thalamus tissue.