Identification in Tetrahymena pyriformis of 3-hydroxy-3-methyl glutaryl coenzyme a lyase: its purification and properties

Int J Biochem. 1987;19(4):385-9. doi: 10.1016/0020-711x(87)90013-9.


The major HMG-CoA utilizing enzyme activity in T. pyriformis has been determined to be HMG-CoA lyase. The enzyme was purified 32-fold to a specific activity of 431 units/mg from a mitochondrial fraction. Sephacryl S-200 chromatography gave an estimated molecular weight of 50,000 daltons for the HMG-CoA lyase. SDS gel electrophoresis revealed two bands stained by Coomassie Blue--a major band of 50,000 daltons and a minor band of 25,000 daltons. The latter is believed to be an impurity in the preparation. The enzyme has a pH optimum of 9.0, is stimulated slightly by sulfhydryl reagents, and requires a divalent cation for maximum activity. The KM for HMG-CoA is 15 microM.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Hydrogen-Ion Concentration
  • Kinetics
  • Oxo-Acid-Lyases / isolation & purification*
  • Tetrahymena pyriformis / enzymology*


  • Oxo-Acid-Lyases
  • 3-hydroxy-3-methylglutaryl-coenzyme A lyase