Shape changes of giant liposomes induced by an asymmetric transmembrane distribution of phospholipids - Inserm - Institut national de la santé et de la recherche médicale Accéder directement au contenu
Article Dans Une Revue Biophysical Journal Année : 1992

Shape changes of giant liposomes induced by an asymmetric transmembrane distribution of phospholipids

Résumé

The influence of a phospholipid transmembrane redistribution on the shape of nonspherical flaccid vesicles was investigated at a fixed temperature by optical microscopy. In a first series of experiments, a transmembrane pH gradient was imposed on egg phosphatidylcholine (EPC)-egg phosphatidylglycerol (EPG) (100:1) giant vesicles. The ApH induced an asymmetric distribution of EPG. Simultaneously, discoid vesicles were transformed into tubular or a series of connected small vesicles. The fraction of phospholipid transfer necessary for a shape change from discoid to two connected vesicles was of the order of 0.1% of the total phospholipids. Additional lipid redistribution was accompanied by a sequence of shape changes. In a second series of experiments, lyso phosphatidylcholine (L-PC) was added to, or subtracted from, the external leaflet of giant EPC vesicles. The addition of L-PC induced a change from discoid to a two-vesicle state without further evolution, suggesting that lipid transfer and lipid addition are not equivalent. L-PC depletion from the outer leaflet generated stomatocyte-like vesicles. Whenever possible, we have determined whether the giant vesicles undergoing shape changes were unilamellar or multilamellar by measuring the elastic area compressibility modulus, K, by the micropipette assay (Kwok and Evans, 1981). Shape transformations triggered by phospholipid modification of the most external bilayer were indeed influenced by the presence of other underlying membranes that played a role comparable to that of a passive cytoskeleton layer. It appears that in real cells, invaginations of the plasma membrane or budding of organelles could be triggered by a phospholipid transfer from one leaflet to the other caused, for instance, by the aminophospholipid translocase which is present in eukaryotic membranes.
Fichier sous embargo
Fichier sous embargo
Date de visibilité indéterminée
Loading...

Dates et versions

inserm-02440829 , version 1 (15-01-2020)

Identifiants

Citer

Philippe F. Devaux, Emmanuel Farge. Shape changes of giant liposomes induced by an asymmetric transmembrane distribution of phospholipids. Biophysical Journal, 1992, 61 (2), pp.347-357. ⟨10.1016/S0006-3495(92)81841-6⟩. ⟨inserm-02440829⟩
24 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More