Purification and characterization of NADP-linked acetoacetyl-CoA reductase from Zoogloea ramigera I-16-M

Biochim Biophys Acta. 1987 Feb 23;917(3):365-71.


An NADP-linked acetoacetyl-CoA reductase was purified to electrophoretic homogeneity from Zoogloea ramigera I-16-M, a poly(3-hydroxybutyrate)-accumulating bacterium. The purified enzyme showed specific activity of 412 mumol acetoacetyl-CoA reduced per min per mg protein, which constituted an 880-fold purification compared to the crude extract, with a 32% yield. Electrophoretic analysis of the purified enzyme which had been cross-linked with dimethylsuberimidate showed that the native enzyme (Mr 92,000) is a tetramer of four identical subunits (Mr 25,500). Among the various D-(-)- and L-(+)-3-hydroxyacyl-CoAs tested, the purified enzyme oxidized only D-(-)-3-hydroxybutyryl-CoA and to a lesser extent D-(-)-3-hydroxyvaleryl-CoA in the presence of NADP+. The antiserum prepared against the purified enzyme completely inhibited poly(3-hydroxybutyrate) synthesis from acetyl-CoA by a crude extract of Z. ramigera I-16-M cells. These findings indicate that this enzyme plays an indispensable role as the supplier of D-(-)-3-hydroxybutyryl-CoA in poly(3-hydroxybutyrate) synthesis in this bacterium.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohol Oxidoreductases / antagonists & inhibitors
  • Alcohol Oxidoreductases / immunology
  • Alcohol Oxidoreductases / isolation & purification*
  • Antibodies, Bacterial / analysis
  • Electrophoresis, Polyacrylamide Gel
  • Hydroxybutyrates / biosynthesis
  • Molecular Weight
  • NADP / isolation & purification*
  • Polyesters*
  • Polymers / biosynthesis
  • Substrate Specificity
  • Zoogloea / enzymology*


  • Antibodies, Bacterial
  • Hydroxybutyrates
  • Polyesters
  • Polymers
  • poly-beta-hydroxybutyrate
  • NADP
  • Alcohol Oxidoreductases
  • acetoacetyl-CoA reductase