3-Hydroxy-3-methylglutaryl coenzyme A lyase from Pseudomonas mevalonii.
HMG-CoA lyase, the putative second intracellular enzyme of mevalonate catabolism in Pseudomonas mevalonii (which we previously referred to as Pseudomonas sp. M (Gill et al. (1984) J. Bacteriol. 160, 294-298, Gill et al. (1985) J. Biol. Chem. 250, 9393-9398 and Sherban, M.S., Thesis, Purdue University), was purified 650-fold from cell extracts to a specific activity of 22 mumol acetyl-CoA formed per min per mg protein. This represents the first published report of the partial purification and characterization of an HMG-CoA lyase from a prokaryotic source. Cleavage of HMG-CoA produced acetyl-CoA and acetoacetate. Activity was optimal at pH 8.8 and was undetectable at or below pH 6.5. The estimated Km for S-HMG-CoA was 100 microM. Both a reduced thiol and Mg2+ or Mn2+ were required for activity. While Mn2+ was preferred at low concentrations, 1 mM or higher concentrations of either cation supported the same maximum velocity. An apparent native Mr of 40,400 +/- 3100 was estimated from gel filtration and sucrose density gradient ultracentrifugation data.
Scher
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Department of Biochemistry, Purdue University, West Lafayette, IN 47907.
Rodwell
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D002413:Cations, Divalent; D002845:Chromatography; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008798:Mevalonic Acid / Q000378:metabolism; D008970:Molecular Weight; D007652:Oxo-Acid-Lyases / Q000302:isolation & purification / Q000378:metabolism*; D011549:Pseudomonas / Q000201:enzymology*
D002413:Cations, Divalent; D007652:Oxo-Acid-Lyases; C021410:3-hydroxy-3-methylglutaryl-coenzyme A lyase; D008798:Mevalonic Acid