ABSTRACT
The studies of oxidative deamination of acetylated polyamines were provoked by the following observation: putrescine injected into mice was mainly degraded by diamine oxidase (DAO). However, in an organ such as the mammalian brain, which does not contain significant activities of DAO, formation of 4-aminobutyrate from putrescine nevertheless occurred at a considerable rate. The well-known oxidative deamination of spermidine and spermine to the corresponding aldehydes by serum amine oxidase (SAO), a copper amine oxidases, is closely analogous to the oxidative deamination of putrescine by DAO. The work of Gahl and Pitot confirmed previous findings concerning the substrate specificity of SAO. DAO activity is high only in a few organs, among which the small intestine is most prominent. The formation of the acetylpolyamines in tissues and their high affinity for Polyamine oxidase suggested that they are the natural substrates of the enzyme.
