Aminoacetone metabolism by semicarbazide-sensitive amine oxidase in rat aorta.
High speed (105,000 g/60 min) membrane fractions from rat aorta homogenates metabolized the aliphatic amine aminoacetone (AA) to methylglyoxal (MG) with a Km of 19 +/- 3 microM, and Vmax of 510 +/- 169 nmol MG/hr/mg protein. This deaminating activity appears to be due to a semicarbazide-sensitive amine oxidase (SSAO), which is associated with smooth muscle cells in blood vessels of the rat and other species. AA was a competitive inhibitor (Ki of 28 +/- 6 microM) of the metabolism of benzylamine, a synthetic amine often used as an assay substrate for SSAO. AA is produced endogenously from mitochondrial metabolism of threonine and glycine, and thus could be a physiological substrate for SSAO, whereas the production of MG by SSAO could have cytotoxic implications for cellular function.
Department of Pharmacology and Clinical Pharmacology, University of Dundee, Ninewells Hospital and Medical School, U.K.
G A
GA
Lyles
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Chalmers
D000096:Acetone / Q000031:analogs & derivatives* / Q000378:metabolism; D006631:Amine Oxidase (Copper-Containing); D000818:Animals; D001011:Aorta / Q000201:enzymology*; D001596:Benzylamines / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010293:Pargyline / Q000031:analogs & derivatives / Q000494:pharmacology; D011437:Propylamines / Q000494:pharmacology; D011765:Pyruvaldehyde / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012663:Semicarbazides / Q000494:pharmacology*; D013347:Subcellular Fractions / Q000201:enzymology
D001596:Benzylamines; D011437:Propylamines; D012663:Semicarbazides; D000096:Acetone; C009054:propargylamine; C010059:carbamylhydrazine; D011765:Pyruvaldehyde; D010293:Pargyline; C030796:benzylamine; D006631:Amine Oxidase (Copper-Containing); D000587:Oxidoreductases Acting on CH-NH Group Donors; C006495:aminoacetone