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.
Lyles
G A
GA
Department of Pharmacology and Clinical Pharmacology, University of Dundee, Ninewells Hospital and Medical School, U.K.
Chalmers
J
J
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