THE ACETOACETATE ACTIVATION AND CLEAVAGE ENZYME SYSTEM

Abstract

Soodak and Lipmann (1) have reported the presence in pigeon liver ext#racts of an enzyme system that catalyzes the formation of acetoacetate from acetate and ATP.'More recently Chou and Lipmann (2) have separated the system which brings about this conversion into (a) a "donor" fraction which catalyzes t.he formation of acetyl CoA from ATP and acet,ate, and (b) an "acceptor" fraction which cat#alyzes the condensation of 2 molecules of acetyl CoA to acetoacetate.Stadtman, Doudoroff, and Lipmann (3) have established that acetoacetate arises from the union of 2 molecules of acetyl CoA.Acetate, unless activated, does not participat.e in this condensat'ion.@lieto acids have been shown by Stern and Ochoa (4) to give rise to citrate in t'he presence of an extract of pigeon liver supplemented with hTP, CoA, and magnesium ions.Stadtman and Barker (5) have also described an enzyme system in extracts of Clostridium kluyveri