Research to be described is to be performed on the bovine plasma amine oxidase, a Cu-amine oxidase, and on the bovine liver monoamine oxidase, a FAD-amine oxidase. Since this is the 3rd year of the project, a great amount of time will be conducted on completing studies in progress. These are in the case of the plasma amine oxidase the completion of the characterization of the A, B and C-forms of the enzyme, completion of the stopped flow investigation of the enzyme-substrate reaction, completion of the reaction with drugs, and the completion of the investigation on the reaction with concanavalin A. In the case of the bovine liver monoamine oxidase, the stopped flow studies will be continued, sequence studies of the enzyme will go forward, the probing of the active site with nitroxide spin labels will be carried out.