Plasma amine oxidase (PAO) catalyzes the reaction:
There are two classes of amine oxidases: the pyridoxal and copper-containing enzyme to which plasma amine oxidase belongs and the FAD-containing amino oxidases. They play an important biological role. See review by Blaschko (1963). Natural substrates include catecholamines, tryptamine derivatives and other physiologically active amines. Amine oxidases from different sources have different substrate specificities. They have been reviewed by Malmström et al. (1975). Considerable literature exists concerning amine oxidases derived from various organs and animals. The amines spermidine and spermine, most specifically oxidized by bovine plasma oxidase, are significant biochemicals; and have been reviewed by Tabor and Tabor (1972) and by Russell (1973). Russell (1973, 1971; and Russell et al. 1971) report an increased urinary excretion of polyamines by cancer patients. This was further expanded on by Lipton et al. (1975), and by Russell, Durie and Salmon (1975). Analysis of low concentrations of the polyamines can be done by gas chromatography and amino acid analysis (Russell 1973), and electrophoresis (Lipton et al. 1975), but older reports showed utility of plasma amine oxidase for fluorometric (Unemoto et al. 1963) and spectrophotometric analysis (Bachrach and Reches 1966). Similar peroxide-detecting systems Guilbault and Kramer 1964; Gochman and Schmitz 1971) could also be adapted. >Bachrach (1970, 1973) deals with this subject in detail along with many other aspects of polyamine functions.
Characteristics of Plasma Amine Oxidase from Bovine Plasma:
Specificity
The major physiological amines oxidized are spermine and spermidine (Yamada and Yasunobu 1962; Yasunobu and Smith 1970; Tabor et al. 1954) and some activity is also seen with benzylamine, homosulfanilamide, furfurylamine and simple aliphatic monoamines. (See also Malmström 1975). There is only slight activity with tyramine, and none with tryptamine, epinephrine, serotonin, or agmatine (Yamada and Yasunobu 1962; Tabor et al. 1954).
= 9.8 (Yamada and Yasunobu 1962).