The oxidation of methylglyoxal by mammalian pyruvate dehydrogenase.
Mammalian pyruvate dehydrogenase actively catalyzed the oxidation of methylglyoxal to acetyl-CoA. The reaction was fully enzymatic with an estimated Km of 1.89 mM. On the other hand, methylglyoxal was a competitive inhibitor of the enzyme for pyruvate, the Ki being in the 1 mM range. The reaction was inhibited in the presence of HgCl2. The reaction products were quantitatively identified as acetyl-CoA and formic acid. A mechanism for the reaction is proposed.
Laboratory of Metabolism, NIAAA, Rockville, Maryland 20852.
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JM
Argilés
D000105:Acetyl Coenzyme A / Q000378:metabolism; D000447:Aldehydes / Q000378:metabolism*; D000818:Animals; D005561:Formates / Q000378:metabolism; D008627:Mercuric Chloride / Q000494:pharmacology; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D011765:Pyruvaldehyde / Q000378:metabolism*; D011768:Pyruvate Dehydrogenase Complex / Q000037:antagonists & inhibitors / Q000378:metabolism*
D000447:Aldehydes; D005561:Formates; D011768:Pyruvate Dehydrogenase Complex; D009243:NAD; C030544:formic acid; D008627:Mercuric Chloride; D000105:Acetyl Coenzyme A; D011765:Pyruvaldehyde