Human liver aldehyde dehydrogenases: new method of purification of the major mitochondrial and cytosolic enzymes and re-evaluation of their kinetic properties

Biochim Biophys Acta. 1994 Apr 13;1205(2):301-7. doi: 10.1016/0167-4838(94)90249-6.


A new purification procedure, based on dye-adsorption and affinity chromatography, has been developed for the isolation of the two major ALDH isozymes from human liver: ALDH-1 (cytosolic, pI 5.2) and ALDH-2 (mitochondrial, pI 4.9). The procedure affords milligram quantities of ALDH-1 and -2 at 850- and 275-fold purifications, respectively, from 50 g of liver in two days. Kinetic parameters for acetaldehyde oxidation were determined with these purified enzymes, because there is a wide discrepancy in the absolute magnitude of these parameters in the biochemical literature. The Michaelis constants for ALDH-1 and -2, determined from initial velocities (for ALDH-1) and single reaction progress curves (for ALDH-2), are 180 +/- 10 microM and 0.20 +/- 0.02 microM, respectively (pH 7.5 and 9.5, saturating NAD+ in both cases). This three orders of magnitude difference in Km values is much greater than that reported previously in all but one study.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetaldehyde / metabolism
  • Aldehyde Dehydrogenase / isolation & purification
  • Aldehyde Dehydrogenase / metabolism*
  • Amino Acids / analysis
  • Chromatography, Affinity / methods
  • Cytosol / enzymology*
  • Humans
  • Isoelectric Point
  • Isoenzymes / isolation & purification
  • Isoenzymes / metabolism*
  • Kinetics
  • Liver / enzymology*
  • Mitochondria / enzymology*
  • Molecular Weight
  • Oxidation-Reduction


  • Amino Acids
  • Isoenzymes
  • Aldehyde Dehydrogenase
  • Acetaldehyde