Enzymatic reaction of beta-N-methylaminoalanine with L-amino acid oxidase.
The reaction of beta-N-methylaminoalanine (BMAA) with L-amino acid oxidase (L-AAO) in the presence of catalase yields ammonia and beta-N-methylaminopyruvate, which was trapped as its 2,4-dinitrophenylhydrazone, as products. Incubation of BMAA with L-AAO in the presence of semicarbazide led to the formation of a semicarbazone, indicating intermediate iminium ion formation; when potassium cyanide (5 mM) was added, semicarbazone formation was blocked. The formation of beta-N-methylaminopyruvate was decreased by omission of catalase and was reduced in the presence of hydrogen peroxide (100 mM). These results indicate that BMAA is converted by L-AAO to the corresponding alpha-imino acid, which undergoes hydrolysis to beta-N-methylaminopyruvate. The alpha-keto acid is readily oxidized to N-methylglycine by hydrogen peroxide.
Hashmi
M
M
Department of Pharmacology, University of Rochester, School of Medicine and Dentistry, NY 14642.
Anders
M W
MW
D000594:Amino Acid Oxidoreductases / Q000737:chemistry*; D000599:Amino Acids, Diamino / Q000737:chemistry*; D002273:Carcinogens / Q000737:chemistry; D002374:Catalase / Q000737:chemistry; D000087522:Cyanobacteria Toxins; D007700:Kinetics; D050830:L-Amino Acid Oxidase; D015394:Molecular Structure; D011190:Potassium Cyanide / Q000737:chemistry; D012663:Semicarbazides / Q000737:chemistry
D000599:Amino Acids, Diamino; D002273:Carcinogens; D000087522:Cyanobacteria Toxins; D012663:Semicarbazides; C001824:beta-N-methylamino-L-alanine; C010059:carbamylhydrazine; D002374:Catalase; D000594:Amino Acid Oxidoreductases; D050830:L-Amino Acid Oxidase; D011190:Potassium Cyanide