title: Transacylation as a chain-termination mechanism in fatty acid synthesis by mammalian fatty acid synthetase. Synthesis of butyrate and hexanoate by lactating cow mammary gland fatty acid synthetase.
abstract: 1. Purified cow mammary gland fatty acid synthetase synthesized long-chain unesterified and short-chain esterified fatty acids. 2. A direct relationship was observed between the amount of short-chain products synthesized and the concentration of acetyl-CoA in the incubation medium. 3. The short-chain products were identified as butyryl-CoA and hexanoyl-CoA. 4. Inhibition of the terminating thioester hydrolase of the fatty acid synthetase complex with phenylmethanesulphonyl fluoride did not inhibit the synthesis of short-chain products. 5. It is suggested that the synthesis of short-chain fatty acids involves the reverse of the 'loading' reaction.
mesh_terms: D000818:Animals; D002087:Butyrates / Q000378:metabolism*; D002208:Caproates / Q000378:metabolism*; D002417:Cattle; D003065:Coenzyme A / Q000378:metabolism; D064429:Fatty Acid Synthases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005227:Fatty Acids / Q000096:biosynthesis; D005230:Fatty Acids, Nonesterified / Q000096:biosynthesis; D005260:Female; D007700:Kinetics; D007774:Lactation; D008321:Mammary Glands, Animal / Q000201:enzymology*; D010664:Phenylmethylsulfonyl Fluoride / Q000494:pharmacology; D011247:Pregnancy; D014280:Triglycerides / Q000096:biosynthesis
chemical_list: D002087:Butyrates; D002208:Caproates; D005227:Fatty Acids; D005230:Fatty Acids, Nonesterified; D014280:Triglycerides; D010664:Phenylmethylsulfonyl Fluoride; D064429:Fatty Acid Synthases; D003065:Coenzyme A