A theoretical model describing the effect of polymer adsorption onto the surface of a mixed lipid membrane has been developed. The model investigates the ability of the adsorbed polymer to induce lateral phase separation of the membrane components forming microdomains richer in one-lipid species. Moreover, the reciprocal influence of these domains on the polymer spreading over the membrane surface as well as on the lipid-polymer binding constant was investigated. The model is based on a variational procedure that minimizes the total energy of the system with respect to some parameters describing the size and composition of the microdomains, the number of adsorbed polymer units, and the polymer spreading over the membrane surface. The resulting equations have been solved by a perturbation technique that yields simple analytical results. Most of the theoretical predictions have been confirmed by differential scanning calorimetry (DSC) measurements performed on a membrane model containing charged (phosphatidic acid) and neutral (phosphatidylcholine) lipids and interacting with a water-soluble poly(amino acid) (polylysine).
|Titolo:||POLYMER-INDUCED LATERAL PHASE-SEPARATION IN MIXED LIPID-MEMBRANES - A THEORETICAL-MODEL AND CALORIMETRIC INVESTIGATION|
|Data di pubblicazione:||1990|
|Appare nelle tipologie:||1.1 Articolo in rivista|