Subcellular location of semicarbazide-sensitive amine oxidase in rat aorta.
With tyramine as substrate, a considerable part of the amine oxidase activity of rat aorta was inhibited by 0.1 mM semicarbazide. The residual activity was little affected by 1 mM semicarbazide. Oxidation of 5-hydroxytryptamine was not inhibited by 0.1 mM semicarbazide. The subcellular location of the semicarbazide-sensitive and semicarbazide-resistant amine oxidases was investigated by analytical density gradient centrifugation. The semicarbazide-resistant enzyme was identified with the mitochondrial monoamine oxidase, located in the outer envelope of mitochondria. The semicarbazide-sensitive amine oxidase was ascribed to the plasma membrane because it was distributed like 5'-nucleotidase and (oligomycin-insensitive) Mg2+-ATPase in various fractionation experiments, and markedly shifted by digitonin towards higher equilibrium densities in sucrose gradient.
D000818:Animals; D001011:Aorta / Q000201:enzymology*; D002462:Cell Membrane / Q000201:enzymology; D002499:Centrifugation, Density Gradient; D004072:Digitonin / Q000494:pharmacology; D005260:Female; D008931:Mitochondria, Muscle / Q000201:enzymology; D008995:Monoamine Oxidase; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D012663:Semicarbazides / Q000494:pharmacology*; D013347:Subcellular Fractions / Q000201:enzymology
D012663:Semicarbazides; D008995:Monoamine Oxidase; D000587:Oxidoreductases Acting on CH-NH Group Donors; D004072:Digitonin