Phase Segregation on Different Length Scales in a Model Cell Membrane System

Jian Liu, Shuyan Qi, Jay T. Groves, Arup K. Chakraborty

Research output: Contribution to journalArticle

Abstract

Lipid rafts are sphingolipid- and cholesterol-enriched domains on cell membranes that have been implicated in many biological functions, especially in T lymphocytes. We used a field theory to examine the forces underlying raft formation on resting living cell membranes. We find that it is difficult to reconcile the observed size of rafts on living cell membranes (∼100 nm) with a mechanism that involves coupling between spontaneous curvature differences and concentration fluctuations. Such a mechanism seems to predict raft domain sizes that are larger and commensurate with those observed on synthetic membranes. Therefore, using a Poisson-Boltzmann approach, we explore whether electrostatic forces originating from transmembrane proteins and net negative charges on cell membranes could play a role in determining the raft size in living cell membranes. We find that a balance among the intrinsic tendency of raft components to segregate, the line tension, and the effective dipolar interactions among membrane constituents leads to a stable phase with a characteristic length scale commensurate with the observed size of rafts on living cell membranes. We calculate the phase diagram of a system in which these three types of forces are important. In a certain region of the parameter space, an interesting phase with mosaic-like morphology consisting of an intertwined pattern of raft and nonraft domains is predicted. Experiments that could further assess the importance of dipolar interactions for lateral organization of the components on multiple length scales in membranes are suggested.

Original languageEnglish (US)
Pages (from-to)19960-19969
Number of pages10
JournalJournal of Physical Chemistry B
Volume109
Issue number42
DOIs
StatePublished - Oct 27 2005
Externally publishedYes

Fingerprint

rafts
Cell membranes
Cell Membrane
Membranes
membranes
Membrane Microdomains
Sphingolipids
T-cells
Electrostatic force
Cholesterol
Static Electricity
Lipids
Phase diagrams
lymphocytes
cholesterol
Proteins
T-Lymphocytes
lipids
tendencies
curvature

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Materials Chemistry

Cite this

Phase Segregation on Different Length Scales in a Model Cell Membrane System. / Liu, Jian; Qi, Shuyan; Groves, Jay T.; Chakraborty, Arup K.

In: Journal of Physical Chemistry B, Vol. 109, No. 42, 27.10.2005, p. 19960-19969.

Research output: Contribution to journalArticle

Liu, Jian ; Qi, Shuyan ; Groves, Jay T. ; Chakraborty, Arup K. / Phase Segregation on Different Length Scales in a Model Cell Membrane System. In: Journal of Physical Chemistry B. 2005 ; Vol. 109, No. 42. pp. 19960-19969.
@article{66740de589e84eba9b064e5d97d1b733,
title = "Phase Segregation on Different Length Scales in a Model Cell Membrane System",
abstract = "Lipid rafts are sphingolipid- and cholesterol-enriched domains on cell membranes that have been implicated in many biological functions, especially in T lymphocytes. We used a field theory to examine the forces underlying raft formation on resting living cell membranes. We find that it is difficult to reconcile the observed size of rafts on living cell membranes (∼100 nm) with a mechanism that involves coupling between spontaneous curvature differences and concentration fluctuations. Such a mechanism seems to predict raft domain sizes that are larger and commensurate with those observed on synthetic membranes. Therefore, using a Poisson-Boltzmann approach, we explore whether electrostatic forces originating from transmembrane proteins and net negative charges on cell membranes could play a role in determining the raft size in living cell membranes. We find that a balance among the intrinsic tendency of raft components to segregate, the line tension, and the effective dipolar interactions among membrane constituents leads to a stable phase with a characteristic length scale commensurate with the observed size of rafts on living cell membranes. We calculate the phase diagram of a system in which these three types of forces are important. In a certain region of the parameter space, an interesting phase with mosaic-like morphology consisting of an intertwined pattern of raft and nonraft domains is predicted. Experiments that could further assess the importance of dipolar interactions for lateral organization of the components on multiple length scales in membranes are suggested.",
author = "Jian Liu and Shuyan Qi and Groves, {Jay T.} and Chakraborty, {Arup K.}",
year = "2005",
month = "10",
day = "27",
doi = "10.1021/jp053562j",
language = "English (US)",
volume = "109",
pages = "19960--19969",
journal = "Journal of Physical Chemistry B Materials",
issn = "1520-6106",
publisher = "American Chemical Society",
number = "42",

}

TY - JOUR

T1 - Phase Segregation on Different Length Scales in a Model Cell Membrane System

AU - Liu, Jian

AU - Qi, Shuyan

AU - Groves, Jay T.

AU - Chakraborty, Arup K.

PY - 2005/10/27

Y1 - 2005/10/27

N2 - Lipid rafts are sphingolipid- and cholesterol-enriched domains on cell membranes that have been implicated in many biological functions, especially in T lymphocytes. We used a field theory to examine the forces underlying raft formation on resting living cell membranes. We find that it is difficult to reconcile the observed size of rafts on living cell membranes (∼100 nm) with a mechanism that involves coupling between spontaneous curvature differences and concentration fluctuations. Such a mechanism seems to predict raft domain sizes that are larger and commensurate with those observed on synthetic membranes. Therefore, using a Poisson-Boltzmann approach, we explore whether electrostatic forces originating from transmembrane proteins and net negative charges on cell membranes could play a role in determining the raft size in living cell membranes. We find that a balance among the intrinsic tendency of raft components to segregate, the line tension, and the effective dipolar interactions among membrane constituents leads to a stable phase with a characteristic length scale commensurate with the observed size of rafts on living cell membranes. We calculate the phase diagram of a system in which these three types of forces are important. In a certain region of the parameter space, an interesting phase with mosaic-like morphology consisting of an intertwined pattern of raft and nonraft domains is predicted. Experiments that could further assess the importance of dipolar interactions for lateral organization of the components on multiple length scales in membranes are suggested.

AB - Lipid rafts are sphingolipid- and cholesterol-enriched domains on cell membranes that have been implicated in many biological functions, especially in T lymphocytes. We used a field theory to examine the forces underlying raft formation on resting living cell membranes. We find that it is difficult to reconcile the observed size of rafts on living cell membranes (∼100 nm) with a mechanism that involves coupling between spontaneous curvature differences and concentration fluctuations. Such a mechanism seems to predict raft domain sizes that are larger and commensurate with those observed on synthetic membranes. Therefore, using a Poisson-Boltzmann approach, we explore whether electrostatic forces originating from transmembrane proteins and net negative charges on cell membranes could play a role in determining the raft size in living cell membranes. We find that a balance among the intrinsic tendency of raft components to segregate, the line tension, and the effective dipolar interactions among membrane constituents leads to a stable phase with a characteristic length scale commensurate with the observed size of rafts on living cell membranes. We calculate the phase diagram of a system in which these three types of forces are important. In a certain region of the parameter space, an interesting phase with mosaic-like morphology consisting of an intertwined pattern of raft and nonraft domains is predicted. Experiments that could further assess the importance of dipolar interactions for lateral organization of the components on multiple length scales in membranes are suggested.

UR - http://www.scopus.com/inward/record.url?scp=27744480393&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=27744480393&partnerID=8YFLogxK

U2 - 10.1021/jp053562j

DO - 10.1021/jp053562j

M3 - Article

C2 - 16853581

AN - SCOPUS:27744480393

VL - 109

SP - 19960

EP - 19969

JO - Journal of Physical Chemistry B Materials

JF - Journal of Physical Chemistry B Materials

SN - 1520-6106

IS - 42

ER -