Some properties of 3-hydroxy-3-methylglutaryl-coenzyme A synthase from ox liver.
Mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (EC 4.1.3.5) was purified from ox liver, and obtained essentially free from 3-oxoacyl-CoA thiolases. The kinetic behaviour, like that of the synthases from chicken liver and yeast, is compatible with a reaction pathway involving condensation of an acetyl-enzyme with acetoacetyl-CoA. The Km for acetoacetyl-CoA, less than 1 micronM at pH 7.8, may possibly be low enough to permit rapid ketogenesis under physiological conditions without the need for a binary complex between the synthase and oxoacyl-CoA thiolase.
D000105:Acetyl Coenzyme A; D000818:Animals; D002417:Cattle; D006904:Hydroxymethylglutaryl-CoA Synthase / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D008930:Mitochondria, Liver / Q000201:enzymology*; D007652:Oxo-Acid-Lyases / Q000378:metabolism*
D000105:Acetyl Coenzyme A; D006904:Hydroxymethylglutaryl-CoA Synthase; D007652:Oxo-Acid-Lyases