Lamellar phase coexistence induced by electrostatic interactions.
Eur Phys J E Soft Matter
; 31(2): 207-14, 2010 Feb.
Article
en En
| MEDLINE
| ID: mdl-20165897
ABSTRACT
Membranes containing highly charged biomolecules can have a minimal free-energy state at small separations that originates in the strongly correlated electrostatic interactions mediated by counterions. This phenomenon can lead to a condensed, lamellar phase of charged membranes that coexists in thermodynamic equilibrium with a very dilute membrane phase. Although the dilute phase is mostly water, entropy dictates that this phase must contain some membranes and counterions. Thus, electrostatics alone can give rise to the coexistence of a condensed and an unbound lamellar phase. We use numerical simulations to predict the nature of this coexistence when the charge density of the membrane is large, for the case of multivalent counterions and for a membrane charge that is characteristic of biomolecules. We also investigate the effects of counterion size and salt on the two coexisting phases. With increasing salt concentration, we predict that electrostatic screening by salt can destroy the phase separation.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Modelos Moleculares
/
Membrana Dobles de Lípidos
/
Fluidez de la Membrana
/
Modelos Químicos
Tipo de estudio:
Prognostic_studies
Idioma:
En
Año:
2010
Tipo del documento:
Article