BINDING OF SPECIFIC ATP CITRATE LYASE AND FATTY-ACID SYNTHETASE ANTIBODIES TO HEAVY POPULATIONS OF RAT-LIVER POLYSOMES

The polysome fractions involved in the synthesis of the rat‐liver inducible lipogenic enzymes, ATP citrate lyase and fatty acid synthetase, were identified by their binding of radioiodinated specific antibodies to enzyme. Both of these populations of specific polysomes were shown to be markedly heavier than the average rat liver polysomes and significantly heavier than specific polysomes involved in albumin synthesis. The quantity of antibody bound to the lipogenic enzyme‐related polysomes was markedly affected by the dietary status of the animal. A dietary regimen which induced lipogenesis resulted in a tenfold increase in the hepatic activities of these enzymes found in normally fed animals. The radioactivity bound to hepatic polysomes of induced rats was likewise greater than tenfold higher, presumably reflecting an increase in the number of polysomes active in enzyme synthesis. The fasting state resulted in lower hepatic enzyme activity than normal and correspondingly less binding of ATP citrate lyase and fatty acid synthetase antibodies to the heavy polysomes of the sucrose gradient. Copyright © 1979, Wiley Blackwell. All rights reserved