The role of phospholipid acyl chains in the activation of mitochondrial ATPase complex

Abstract

SUMMARY1. The role of length and unsaturation of phospholipid acy! chains in the activation of ATPase complex was studied with synthetic phosphatidylcholines and a phospholipid-dependent preparation obtained after cholate-extraction of submitochondrial particles (Kagawa, Y. and Racker, E. (1966) J. Biol. Chem. 241, 2467-2474.2. Micelle-forming, short-chain phosphatidylcholines produced activation only at critical micellar concentration. The reactivated complex was cold-stable but the oligomycin sensitivity was low.3. Bilayer-forming saturated phosphatidylcholines produced activation which was maximal at 9 carbon atoms in each chain but decreased sharply as the chainlength was increased and essentially disappeared at 14 carbon atoms. By contrast the oligomycin-sensitivity increased with the increase in chain length.4. Activation of ATPase complex reappeared when bilayers were formed with long-chain unsaturated phosphatidylcholines. The activity was oligomycin sensitive. Significant inhibition of activity was observed also after incorporation of cholesterol into the bilayers.5. By contrast the activation induced by negatively charged liposomes of diacylphosphatidyiglycerol was independent on acyi-chain composition and occurred at very low amounts of phospholipid.6. The discontinuity in the Arrhenius plot of activity of the ATPase complex reactivated with saturated phospholipids was found at temperatures close to the gelto-liquid crystalline transition of the lipid showing that the activity of ATPase complex was sensitive to the physical state of membrane phospholipids.7. It is concluded that (a) reactivation of ATPase complex by isoelectric phospholipids is an interracial activation, the minimum requirement for the lipid effect being micelle formation. (b) In order to gain the properties of the native complex a stable lamellar phase is needed. Both activity and oligomycin sensitivity are regulated by the chain length and degree of unsaturation of phospholipid acyl chains.

Cold acclimation or grapeseed oil feeding affects phospholipid composition and mitochondrial function in duckling skeletal muscle

“…The ATPase complex activity was already shown to be regulated by the chain length and the degree of unsaturation of membrane FA (42). The GO diet had less clear-cut effects on the ATP synthesis, despite marked changes in membrane PUFA, possibly because the proportion of the 18:2n-6 was also markedly increased.…”

Analysis of hepatic transcript profile and plasma lipid profile in early lactating dairy cows fed grape seed and grape marc meal extract

“…The finding that fatty acid moieties of plasma phospholipids were also not changed in the group of cows supplemented with GSGME indicates that polyphenols also did not influence hepatic desaturation and elongation of fatty acids. This finding is of relevance as the fatty acid composition of phospholipids not only influences properties of cellular membranes [89], but certain phospholipid-bound fatty acids such as arachidonic acid are serving also as precursors for the synthesis of pro-inflammatory eicosanoids [90]. The finding that supplementation of GSGME did not influence the concentrations of free cholesterol and cholesterol esters indicates that polyphenols do not modify hepatic cholesterol metabolism.…”

Effect of Polar Lipids on ATPase Activity of Membrane Preparations from Germinating Radish Seeds

“…The involvement of polar lipids in the functionality of ATPase has been demonstrated with preparations from animal tissues and microorganisms (9,17,24) and, more recently, the effect ofvarious phospholipids on the ATPase has been investigated (6,11).…”