title: Reaction of fungal amine oxidase with beta-bromoethylamine.
abstract: beta-Br-ethylamine is both a substrate and an irreversible inhibitor of amine oxidase from Aspergillus niger. The enzyme catalyzes the nonoxidative elimination of HBr from beta-Br-ethylamine to form acetaldehyde. beta-Br-ethylamine meets several criteria for an irreversible substrate analog or suicide inhibitor. 1) It inactivates the oxidized enzyme, but not the reduced enzyme. 2) The Michaelis constant for beta-Br-ethylamine in the elimination reaction showed a similar magnitude to that of the related constant found when the haloamine acted as an inhibitor. 3) The enzyme was protected from the inactivation by the co-existence of the substrate. 4) Inactivation with beta-Br-[14C]ethylamine resulted in the incorporation of radioactivity corresponding to 1 mol of the label/mol of the monomeric unit of the enzyme and a decrease of 1 mol of the -SH group. 5) Inactivation was accompanied by the formation of a new absorption peak at 320 nm which was bleached by addition of NaBH4.
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001234:Aspergillus niger / Q000201:enzymology*; D005021:Ethylamines / Q000494:pharmacology*; D007700:Kinetics; D010084:Oxidation-Reduction; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000378:metabolism*; D013053:Spectrophotometry
chemical_list: D005021:Ethylamines; D000587:Oxidoreductases Acting on CH-NH Group Donors