title: Manipulation of the phosphatidylethanolamine pool in the human red cell membrane affects its Mg2+-ATPase activity.
abstract: Decreasing the size of the outer leaflet pool of phosphatidylethanolamine (PE) in the erythrocyte membrane by treatment of intact cells with either phospholipase A2, or trinitrobenzenesulphonic acid (TNBS), causes a corresponding decrease in Mg(2+)-ATPase activity as determined in their respective ghosts. Also, incubation of ghosts with Ro09-0198, a cyclic peptide from Streptoverticillium which is known to interact specifically with PE, causes a decrease in Mg(2+)-ATPase activity which is dependent on the amount of peptide added. These three different approaches, all causing a decrease in endogenous PE, thus result in a concomitant decrease in Mg(2+)-ATPase activity which reaches a plateau level at approximately 25% residual activity. Hence, it is inferred that the complementary fraction (75%) of the total Mg(2+)-ATPase in the red cell membrane is closely related to the functioning of its aminophospholipid specific translocase as it mediates a (continuous) transport of PE molecules from outer to inner membrane leaflet. This view is supported by the observation that an increase in the total amount of PE in the membrane by decarboxylation of an appreciable fraction of its PS, results in a considerable increase in Mg(2+)-ATPase activity.
authors.affiliation: Department of Lipid Biochemistry, Utrecht University, The Netherlands.
authors.forename: W P
authors.initials: WP
authors.lastname: Vermeulen
authors.forename: J J
authors.initials: JJ
authors.lastname: Briedé
authors.forename: B
authors.initials: B
authors.lastname: Roelofsen
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology; D001692:Biological Transport; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D002262:Carboxy-Lyases / Q000378:metabolism / Q000494:pharmacology; D002352:Carrier Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003653:Decarboxylation; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D006801:Humans; D008274:Magnesium / Q000378:metabolism*; D008563:Membrane Lipids / Q000737:chemistry / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D010455:Peptides; D010456:Peptides, Cyclic; D010714:Phosphatidylethanolamines / Q000737:chemistry / Q000378:metabolism*; D010718:Phosphatidylserines / Q000378:metabolism; D010741:Phospholipases A / Q000378:metabolism / Q000494:pharmacology; D054467:Phospholipases A2; D049294:Phospholipid Transfer Proteins; D014302:Trinitrobenzenesulfonic Acid / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D002352:Carrier Proteins; D008563:Membrane Lipids; D008565:Membrane Proteins; D010455:Peptides; D010456:Peptides, Cyclic; D010714:Phosphatidylethanolamines; D010718:Phosphatidylserines; D049294:Phospholipid Transfer Proteins; C055996:lanthiopeptin; D014302:Trinitrobenzenesulfonic Acid; D010741:Phospholipases A; D054467:Phospholipases A2; D017301:Ca(2+) Mg(2+)-ATPase; D002262:Carboxy-Lyases; C022353:phosphatidylserine decarboxylase; D008274:Magnesium