Medical implications from the crystal structure of a copper‐containing amine oxidase complexed with the antidepressant drug tranylcypromine

Abstract

The X‐ray crystal structure of the copper‐containing quinoprotein amine oxidase from E. coli has been determined in complex with the antidepressant drug tranylcypromine to 2.4 Å resolution. The drug is a racemic mix of two enantiomers, but only one is seen bound to the enzyme. The other enantiomer is not acting as a substrate for the enzyme as no catalytic activity was detected when the enzyme was initially exposed to the drug. The inhibition of human copper amine oxidases could be a source of side‐effects in its use as an antidepressant to inhibit the flavin‐containing monoamine oxidases in the brain.