DENOVO FATTY-ACID SYNTHESIS IN EEL-LIVER CYTOSOL

1. 1. Some of the characteristics and cofactor requirements of acetyl-CoA carboxylase and fatty acid synthetase, both of which show remarkable activity in ell-liver cell sap, were investigated. 2. 2. For optimal activity, acetyl-CoA carboxylase needed preincubation with citrate and was inhibited by avidin and palmityl-CoA. The latter inhibition was reversed by increasing citrate concentrations. 3. 3. Fatty acid synthetase required NADPH as hydrogen donor. Among NADPH furnishing enzymes, the highest activity was associated with glucose-6-phosphate dehydrogenase and isocitrate dehydrogenase. 4. 4. The ratio of total radioactivity to radioactivity in carboxyl carbon of the synthesized fatty acids indicated that a de novo mechanism of fatty acid synthesis is operative in eel-liver cytosol. © 1989.