Active-sitve titration of pig plasma benzylamine oxidase with phenylhydrazine

Abstract

Pig plasma benzylamine oxidase is a protein containing cupric copper and pyridoxal phosphate. The pyridoxal phosphate is stably linked to the enzyme. Discrepancies in the numbers of active sites per molecule of enzyme are reported in the literature. This paper shows that the fully active pure enzyme contains 3 mol of pyridoxal phosphate per mol, whereas enzymes with a lower specific activity are shown by titration with phenylhydrazine to have a lower pyrdoxal phosphate content.