Novel copper amine oxidase activity from rat liver mitochondria matrix.
Copper containing amine oxidases (Cu-AO) represent a heterogeneous class of enzymes classified as EC 1.4.3.6. The present study reports preliminary results on the presence of a novel amine oxidase activity in rat liver mitochondria lysates. Such enzymatic activity was found in the soluble mitochondrial fraction, obtained by simple osmotic shock. The mitochondrial amine oxidase was isolated by affinity chromatography on a newly synthesised spermine-Sepharose. SDS-PAGE showed a single band at about 60kDa. Upon chromatographic purification, the enzymatic activity was very labile. The crude enzyme activity was tested by spectrophotometric measurements, determining hydrogen peroxide production following oxidative deamination of different substrates, such as polyamines (spermine, spermidine, putrescine and cadaverine) and monoamines (dopamine and benzylamine). The activity, observed on polyamines and not on monoamines, was inhibited by semicarbazide and azide, but not by pargyline, clorgyline and l-deprenil. Enzyme specificity was tested on several diamines characterized by different carbon atom chain length in the range 2-6 carbon atoms. The highest activity was found with 1,2-diamino-ethane and the highest affinity with 1,5-diamino-pentane. The above reported results suggest the presence of a novel copper-dependent amine oxidase in liver mitochondria matrix.
Cardillo
Sara
S
Department of Biological Chemistry, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy.
Iuliis
Angela De
AD
Battaglia
Valentina
V
Toninello
Antonio
A
Stevanato
Roberto
R
Vianello
Fabio
F
D006631:Amine Oxidase (Copper-Containing) / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D046529:Microscopy, Electron, Transmission; D008930:Mitochondria, Liver / Q000201:enzymology*; D009994:Osmolar Concentration; D051381:Rats; D013379:Substrate Specificity
D004791:Enzyme Inhibitors; D006631:Amine Oxidase (Copper-Containing)