ABSTRACT
This chapter examines what is known about the Cu-AO which occurs in the plasma of mammals. Emphasis is placed on the mechanism of action of the enzyme. Highly purified Serum amine oxidase (SAO) has been isolated from rabbit, human, pig, and bovine plasma. Substrates such as benzylamine and heptylamine are readily oxidized by SAO from all sources examined. The converse specificity pattern applies for SAO from ruminants. Detailed data on substrate and inhibitor specificities of SAO from different sources can be found in the review of Buffoni. SAO contains two copper atoms per enzyme molecule. SAO contains a catalytically essential prosthetic group which interacts strongly with a variety of carbonyl reagents. Steady-state kinetic studies indicate that SAO operates by an enzyme-substitution (ping-pong) mechanism, but the order of substrate binding and product release cannot be reliably deduced from reported product inhibition data.
