SPECIFIC-INHIBITION OF PLANT FATTY-ACID ELONGATION BY A LONG-CHAIN CERULENIN ANALOG

Cerulenin analogues with 16 or 18 carbon atoms inhibit both ATP-dependent and acyl-CoA-dependent fatty acid elongations. Prior incubation of microsomes with inhibitors is necessary to obtain maximal inhibition. The analogues act on the first reaction of the elongation process catalysed by the 3-ketoacyl-CoA synthase. The 18-carbon analogue has no, or little, effect on the fatty acid synthesis, while cerulenin and its 16-carbon analogue totally inhibit this synthesis. The Is-carbon analogue appears to be a specific inhibitor of the synthesis of very long-chain fatty acids, with no effect on de novo fatty acid synthesis.