Purification and characterization of semicarbazide-sensitive amine oxidase from porcine aorta

We purified semicarbazide-sensitive amine oxidase (SSAO) from porcine aorta by sequential DEAE-Sephacel, DEAE-Sephadex and Affi-gel-Con A chromatography. The analysis of this protein under denaturing conditions exhibited two protein bands migrating at 110-107 kDa. Under non-denaturing conditions only a single protein band was observed. By isoelectric focusing pI of SSAO was estimated to be 5.5. The apparent Km and Vmax of porcine SSAO for oxidation of benzylamine were 4.5 microM and 200 nmol/hr/mg protein, respectively. Porcine SSAO was inhibited both by semicarbazide and phenelzine while deprenyl or clorgyline were without any effect on enzyme activity. IC50 for inhibition of semicarbazide and phenelzine was 0.015 microM and 1 nmol, respectively.