Oleic acid desaturation in Tetrahymena pyriformis.
The desaturation of oleoyl-CoA by a microsomal preparation from Tetrahymena has been studied. Desaturation of oleoyl-CoA required oxygen and NADH, and was inhibited by cyanide. HPLC analysis of fatty acid phenacyl esters, prepared from TLC-purified phospholipid, confirmed that radioactivity appeared in oleate, linoleate and gamma-linolenate. Both the time course of desaturation and the apparent desaturation of 1-palmitoyl-2-[14C]oleoylphosphatidylcholine suggested that phospholipid-bound oleate could be a substrate for desaturation. In the crude microsomal preparation, acylation of oleoyl-CoA to give oleoyl phospholipid was rapid. Therefore, preincubation in the absence of NADH was employed to create [14C]oleoyl phospholipids, and kinetic studies were carried out upon subsequent addition of NADH. When data were plotted in a double reciprocal form, a linear function was observed.
D000214:Acyl Coenzyme A / Q000378:metabolism*; D055598:Chemical Phenomena; D002621:Chemistry; D008861:Microsomes / Q000201:enzymology*; D009243:NAD / Q000494:pharmacology; D009829:Oleic Acids / Q000378:metabolism*; D010100:Oxygen / Q000494:pharmacology; D010743:Phospholipids / Q000378:metabolism; D013768:Tetrahymena / Q000201:enzymology*
D000214:Acyl Coenzyme A; D009829:Oleic Acids; D010743:Phospholipids; D009243:NAD; C017585:oleoyl-coenzyme A; D010100:Oxygen