2-Hydroxyacid dehydrogenase from Haloferax mediterranei, a D-isomer-specific member of the 2-hydroxyacid dehydrogenase family

Biochimie. 2000 Dec;82(12):1143-50. doi: 10.1016/s0300-9084(00)01193-7.


An NAD-dependent D-2-hydroxyacid dehydrogenase (EC 1.1.1.) was isolated and characterized from the halophilic Archaeon Haloferax mediterranei. The enzyme is a dimer with a molecular mass of 101.4 +/- 3.3 kDa. It is strictly NAD-dependent and exhibits its highest activity in 4 M NaCl. The enzyme is characterized by a broad substrate specificity 2-ketoisocaproate and 2-ketobutyrate being the substrates with the higher Vmax/Km. When pyruvate and 2-ketobutyrate were the substrates the optimal pH was acidic (pH 5) meanwhile for 2-ketoisocaproate maximum activity was achieved at basic pH between 7.5 and 8.5. The optimum temperature was 52 degrees C and at 65 degrees C there was a pronounced activity decrease. This new enzyme can be used for the production of D-2-hydroxycarboxylic acid.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohol Oxidoreductases / drug effects
  • Alcohol Oxidoreductases / isolation & purification*
  • Alcohol Oxidoreductases / metabolism*
  • Carboxylic Acids / metabolism
  • Enzyme Stability / drug effects
  • Haloferax mediterranei / enzymology*
  • Hydrogen-Ion Concentration
  • Isoenzymes
  • Keto Acids / metabolism*
  • Kinetics
  • Mass Spectrometry / methods
  • Molecular Structure
  • Molecular Weight
  • Salts / pharmacology
  • Substrate Specificity
  • Temperature


  • Carboxylic Acids
  • Isoenzymes
  • Keto Acids
  • Salts
  • Alcohol Oxidoreductases
  • 2-hydroxyacid dehydrogenase