Purification and Some Properties of ATP Citrate Lyase from Penicillium spiculisporum

Abstract

ATP citrate lyase occurs in large quantities in Penicillium spiculisporum. It has been purified 25 fold to a specific activity of 3.6 U/mg. At optimal concentrations of the other substrates apparent Km values are: citrate, 180μM; ATP, 90 μM and CoASH 1–3 μM. The enzyme is Mg2+ dependent, but Mn2+ and Co2+ can also be used. 1,N6‐Etheno‐adenosine triphosphate is active as a substrate with a Km of 180 μM, but 1,N6‐etheno‐coenzyme A is not. 2‐Decylcitric acid is not a substrate for the enzyme. ATP citrate lyase has a molecular weight of above 200000. The amount of ATP citrate lyase in Penicillium spiculisporum is such as to support the hypothesis that citrate is a precursor of fatty acids in the organism. Copyright © 1973, Wiley Blackwell. All rights reserved