These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Toward a better raft model: modulated phases in the four-component bilayer, DSPC/DOPC/POPC/CHOL.
    Author: Goh SL, Amazon JJ, Feigenson GW.
    Journal: Biophys J; 2013 Feb 19; 104(4):853-62. PubMed ID: 23442964.
    Abstract:
    The liquid-liquid (Ld + Lo) coexistence region within a distearoyl-phosphatidylcholine/dioleoyl-phosphatidylcholine/palmitoyl-oleoyl-phosphatidylcholine/cholesterol (DSPC/DOPC/POPC/CHOL) mixture displays a nanoscopic-to-macroscopic transition of phase domains as POPC is replaced by DOPC. Previously, we showed that the transition goes through a modulated phase regime during this replacement, in which patterned liquid phase morphologies are observed on giant unilamellar vesicles (GUVs). Here, we describe a more detailed investigation of the modulated phase regime along two different thermodynamic tielines within the Ld + Lo region of this four-component mixture. Using fluorescence microscopy of GUVs, we found that the modulated phase regime occurs at relatively narrow DOPC/(DOPC+POPC) ratios. This modulated phase window shifts to higher values of DOPC/(DOPC+POPC) when CHOL concentration is increased, and coexisting phases become closer in properties. Monte Carlo simulations reproduced the patterns observed on GUVs, using a competing interactions model of line tension and curvature energies. Sufficiently low line tension and high bending moduli are required to generate stable modulated phases. Altogether, our studies indicate that by tuning the lipid composition, both the domain size and morphology can be altered drastically within a narrow composition space. This lends insight into a possible mechanism whereby cells can reorganize plasma membrane compartmentalization simply by tuning the local membrane composition or line tension.
    [Abstract] [Full Text] [Related] [New Search]