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[摘要]：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 Oil 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 oil a newly synthesised spermine-Sepharose. SDS-PAGE showed a single hand at about 60 kDa. Upon chromatography 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 oil several diamines characterized by different carbon atom chain length in the range 2-6 carbon atoms. The highest activity was found with 1,2-daimino-ethane and the highest affinity with 15-diamino-pentane. The above reported results suggest the presence of a novel copper-dependent amine oxidase in liver mitochondria matrix. (C) 2009 Elsevier Inc. All rights reserved. |
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