Solution Asymmetry and Salt Expand Fluid-Fluid Coexistence Regions of Charged Membranes.

ABSTRACT: Liquid-liquid phase separation in giant unilamellar vesicles (GUVs) leads to the formation of intramembrane domains. To mimic charged biological membranes, we studied phase separation and domain formation in GUVs of ternary lipid mixtures composed of egg sphingomyelin, cholesterol, and the negatively charged lipid dioleoylphosphatidylglycerol. The GUVs were exposed to solutions of sucrose and high-saline buffer. The phase diagram was determined using epifluorescence microscopy for vesicle populations with symmetric and asymmetric solution compositions across the membranes. Trans-membrane solution asymmetry was found to affect the membrane phase state. Furthermore, compared to the case of salt-free conditions, the phase diagram in the presence of high-saline buffer (both symmetrically or as

SUBMITTER: Kubsch B 

PROVIDER: S-EPMC4919722 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature