出版社:American Society for Biochemistry and Molecular Biology
摘要:Lipid synthesis by rat liver microsomes from l -α-glycerophosphate-1-C14 in the presence of palmitic acid, ATP, CoA, and Mg2+ came to a standstill after 30 min while enough cofactors were still present to promote further synthesis. The extent of the reaction depended on the amount of microsomes. Doubling the microsome concentration more than doubled the extent of synthesis. Synthesis of both neutral lipids and phospholipids could be promoted by the addition of inactivated microsomes as well as by serum albumin and by various lipoprotein preparations. A 20- to 40-fold increase of ester yield could be obtained by supplementing low concentrations of microsomes with the proteins. Ovolecithin also had a considerable activating effect. Lipoproteins had an activating effect even in the presence of optimal albumin concentrations, pointing to different modes of action of the two proteins. The hypothesis is discussed that microsomes synthesize lipoproteins and that lipid synthesis is limited by the amount of acceptor protein available.