Tranylcypromine, also known as 2-PCPA, is a monoamine oxidase inhibitor (MAOI) that irreversibly inhibits MAO A and MAO B with the inhibition constant Ki values of 101.9 μM and 16 μM and the half maximal inhibition concentration IC50 values of 2.3 μM and 0.95 μM respectively [1].
Tranylcypromine has also been found to potently and irreversibly inhibit histone demethylase lysine-specific demethylase 1 (LSD1), which is an amine oxidase homologue of MAO sharing similarities in the catalytic site with MAO A and B, in a time dependent and mechanism based manner with Ki and IC50 values of 242 μM and 20.7 μM respectively [1].
Reference
References:
[1] Schmidt DM, McCafferty DG. trans-2-Phenylcyclopropylamine is a mechanism-based inactivator of the histone demethylase LSD1. Biochemistry. 2007 Apr 10;46(14):4408-16. Epub 2007 Mar 17.