A comparison between diamine oxidases from human post-heparin blood serum, pregnancy blood serum and amniotic fluid.

Diamine oxidase (DAO) was purified from blood serum after intravenous heparin injection, from pregnancy blood serum and amniotic fluid. On DEAE-Sephadex, DAO from amniotic fluid as well as from pregnancy blood serum was separated in two active fractions with molecular weights of 245,000 and 485,000, respectively. Post-heparin blood serum contained only one active DAO fraction with a molecular weight of 185,000. The purified enzymes showed similar enzymatic properties.