The esterification of dolichol by rat liver microsomes

The incubation of 1-[3H)dolichols with cell-free preparations from various rat tissues resulted in the formation of a labeled material which possessed the characteristics of synthetic dolichol palmitate. Rat liver microsomes were found to be a good source of the acyltransferase activity, and the properties of the reaction were investigated using microsomal preparations. The reaction did not require ATP, CoA, or Mg2+ and was stimulated by the addition of phosphatidylcholine. The esterification of dolichol appears to be similar to the esterification of retinol. The fact that the esterification of dolichol is not depressed even in the presence of a several-fold excess of retinol is evidence that the two reactions are catalyzed by different enzymes.