Open AccessAgmatine oxidation by copper amine oxidase
Author(s) -
Ascenzi Paolo,
Fasano Mauro,
Marino Maria,
Venturini Giorgio,
Federico Rodolfo
Publication year - 2002
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.0014-2956.2002.02718.x
Subject(s) - agmatine , chemistry , amine gas treating , trypsin , amine oxidase , nitric oxide synthase , medicinal chemistry , copper , stereochemistry , nuclear chemistry , enzyme , biochemistry , organic chemistry , putrescine
The product of agmatine oxidation catalyzed by Pisum sativum L. copper amine oxidase has been identified by means of one‐ and two‐dimensional 1 H‐NMR spectroscopy to be N ‐amidino‐2‐hydroxypyrrolidine. This compound inhibits competitively rat nitric oxide synthase type I and type II (NOS‐I and NOS‐II, respectively) and bovine trypsin (trypsin) activity, values of K i being (1.1 ± 0.1) × 10 −5 m (at pH 7.5 and 37.0 °C), (2.1 ± 0.1) × 10 −5 m (at pH 7.5 and 37.0 °C), and (8.9 ± 0.4) × 10 −5 m (at pH 6.8 and 21.0 °C), respectively. Remarkably, the affinity of N ‐amidino‐ 2‐hydroxypyrrolidine for NOS‐I, NOS‐II and trypsin is significantly higher than that observed for agmatine and clonidine binding. Furthermore, N ‐amidino‐2‐hydroxypyrrolidine and agmatine are more efficient than clonidine in displacing [ 3 H]clonidine (= 1.0 × 10 −8 m ) from specific binding sites in heart rat membranes, values of IC 50 being (1.3 ± 0.4) × 10 −9 m and (2.2 ± 0.4) × 10 −8 m , respectively (at pH 7.4 and 37.0 °C).