Diamine and polyamine catabolism controls plant development, resistance to pathogens and stress responses. Diamine and polyamine oxidases control the catabolism of diamines and polyamines, respectively. Two major routes of di-/polyamine catabolism exist: the terminal and the interconverting. The in vitro activity of each route is assayed by the colorimetric or chemiluminescent determination of hydrogen peroxide produced by oxidation of di-/polyamine substrates. However, these assays fail to estimate activity of individual di-/polyamine oxidase isoenzymes. Herein, I describe an assay for the simultaneous in-gel determination of terminal and interconverting di-/polyamine oxidase isoenzyme activities.
Keywords: Diamine oxidases; Flavin adenine dinucleotide; Hydrogen peroxide; Oxidation; Peroxisomes; Polyamine back-conversion; Polyamine interconversion; Polyamine oxidases; Spermidine.