Purification and characterization of 2-oxoaldehyde dehydrogenase from rat liver.

The partial purification (123-fold) of 2-oxoaldehyde dehydrogenase (2-oxoaldehyde:NAD(P)+ oxidoreductase, 1.2.1.23) from rat liver was carried out using a purification procedure which involved (NH4)2SO4 fractionation, DEAE-Sephadex chromatography, Blue-Dextran affinity chromatography and CM-Sephadex chromatography. A single form of the enzyme was observed, mol. wt. approx. 50000 by gel chromatography. 2-Oxoaldehyde dehydrogenase appears to be highly specific for NADP+ and methylglyoxal. No activity is observed in the absence of certain amines which have vicinal amino and hydroxyl groups. The only known amine which activates the enzyme at physiological pH is L-serine methyl ester, suggesting that the regulation of this enzyme in vivo may require a derivative of serine.