Diamine oxidase from porcine kidney is a homodimer consisting of 2 equal subunits with a molecular weight of 87 kDa each. Each subunit contains one molecule of pyridoxal phosphate and one atom of copper. The molecular mass of the enzyme is found to be 170 kDa. The enzyme is a glycoprotein containing 5% hexose, 3.3% glucosamine, 2.6% N-acetylglucosamine, and 0.25% N-acetylneuraminic acid. The enzyme exhibits a high affinity for concanavalin A. It catalyzes the oxidation of monoamines, diamines, and histamine to aldehydes, ammonia, and hydrogen peroxide. Optimum pH with cadverine and histamine as substrates is found to be 6.3-7.4.2 The enzyme is classified as a copper amine oxidase and it is a key enzyme in nitrogen metabolism. It is inhibited by diethyldithiocarbamate, phenylhydrazine, semicarbazide, cyanide, isonicotinic acid hydrazide.http://www.creative-enzymes.com/product/Native-Plant-Origin-Diamine-Oxidase_1706.html