Journal article
Fatty acid biosynthesis VII. Substrate control of chain-length of products synthesised by rat liver fatty acid synthetase
- 1. Gas-liquid and paper chromatography have been used to determine the chain-lengths of fatty acids synthesised by purified rat liver fatty acid synthetase from [1-14C]acetyl-CoA, [1,3-14C2]malonyl-CoA and from [1-14C]acetyl-CoA plus partially purified rat liver acetyl-CoA carboxylase. - 2. A wide range (C4:0–C18:0) of fatty acids was synthesised and the proportions were modified by substrate concentrations in the same manner as for purified rabbit mammary gland fatty acid synthetase. - 3.
The relative amount of radioactivity incorporated from added acetyl-CoA and malonyl-CoA depended on the substrate concentrations used. At excess acetyl-CoA to malonyl-CoA, greater amounts of acetyl-CoA were incorporated than theoretically expected from the malonyl-CoA pathway. At excess malonyl-CoA, less acetyl-CoA was incorporated than theoretically expected. - 4.
An increase in the chain-length of fatty acids synthesised from malonyl-CoA was observed with increasing malonyl-CoA concentrations and malonyl-CoA to acetyl-CoA ratios. A similar increase was observed when increasing amounts of a malonyl-CoA generating system were added. However, at the same overall rate of synthesis, a lower proportion of long-chain fatty acids was synthesised from carboxylated acetyl-CoA than from added malonyl-CoA. - 5.
It is suggested that acetyl-CoA carboxylase may carboxylate acetate bound to fatty acid synthetase.
Language: | English |
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Year: | 1970 |
Pages: | 400-410 |
ISSN: | 1879145x , 00052760 and 00063002 |
Types: | Journal article |
DOI: | 10.1016/0005-2760(70)90035-4 |