title: Time-dependent inhibition of pea cotyledon diamine oxidase by some hydrazides.
abstract: The inhibition of diamine oxidase (EC 1.4.3.6) from pea cotyledons (PDAO) by some hydrazides has been studied. It was found that PDAO is inhibited in a time-dependent manner at pH = 7.0 by the hydrazides of acetic, benzoic, nicotinic, isonicotinic, picolinic and 3,4-dihydro-4-oxophtalazine-1-carboxylic acids, by 1-(carboxymethyl)trimethylammonium chloride hydrazide (Girard's reagent T), 1-(carboxymethyl)pyridinium chloride hydrazide (Girard's reagent P) and oxalic acid dihydrazide. The inhibition was partially reversible. Rate constants for enzyme inactivation were in the range 0.29-1.95 min-1. The hydrazides give apparent noncompetitive inhibition at pH = 7.0, but for isonicotinic hydrazide, this changes to competitive inhibition at pH = 8.0. Apparent inhibition constants (K1APP) for the hydrazides with PDAO are in the range 0.005-1.5 mmol l-1.
authors.affiliation: Department of Analytical and Organic Chemistry, Faculty of Science, Palacký University, Olomouc, Czechoslovakia.
authors.forename: P
authors.initials: P
authors.lastname: Pec
authors.forename: A
authors.initials: A
authors.lastname: Haviger
authors.forename: D
authors.initials: D
authors.lastname: Kopecná
authors.forename: I
authors.initials: I
authors.lastname: Frébort
mesh_terms: D006631:Amine Oxidase (Copper-Containing) / Q000037:antagonists & inhibitors*; D007887:Fabaceae / Q000201:enzymology*; D006834:Hydrazines / Q000494:pharmacology*; D007700:Kinetics; D008956:Models, Chemical; D010946:Plants, Medicinal
chemical_list: D006834:Hydrazines; D006631:Amine Oxidase (Copper-Containing)