title: Phospholipid asymmetry during erythrocyte deformation: maintenance of the unit membrane.
abstract: To assess the red blood cell (RBC) membrane's ability to maintain normal phospholipid orientation in the face of deforming stress, we examined RBC subjected to elliptical, tank-treading deformation. As determined by accessibility to phospholipase digestion and by labelling with fluorescamine, normal RBC are able to fully preserve their phospholipid asymmetry despite attaining over 96% of their maximal possible deformation. Phospholipid orientation is unchanged during deformation even for RBC that are ATP-depleted or vanadate-treated and for RBC that already have destabilized phospholipids due to treatment with t-butyl hydroperoxide. These data indicate that maintenance of phospholipid organization during marked deforming stress and tank-treading motion of the membrane is ascribable predominantly to the passive stabilizing effect of membrane proteins. This provides additional evidence for the concept of a unit membrane characterized by intimate associations between lipid and protein.
authors.affiliation: Department of Medicine, University of Minnesota Medical School, Minneapolis.
authors.forename: T
authors.initials: T
authors.lastname: Sugihara
authors.forename: K
authors.initials: K
authors.lastname: Sugihara
authors.forename: R P
authors.initials: RP
authors.lastname: Hebbel
mesh_terms: D002412:Cations / Q000378:metabolism; D004910:Erythrocyte Membrane / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D010743:Phospholipids / Q000502:physiology*; D013314:Stress, Mechanical
chemical_list: D002412:Cations; D010743:Phospholipids