Language selection

Government of Canada / Gouvernement du Canada

Search

Cholesterol-dependent nanomechanical stability of phase-segregated multicomponent lipid bilayers

From National Research Council Canada

Download
  1. (PDF, 891 KiB)
DOIResolve DOI: https://doi.org/10.1016/j.bpj.2010.04.044
AuthorSearch for: 1; Search for: ; Search for: 1; Search for: ; Search for: 1
Affiliation
  1. National Research Council of Canada. NRC Steacie Institute for Molecular Sciences
FormatText, Article
Abstract
Cholesterol is involved in endocytosis, exocytosis, and the assembly of sphingolipid/cholesterol-enriched domains, as has been demonstrated in both model membranes and living cells. In this work, we explored the influence of different cholesterol levels (5–40 mol %) on the morphology and nanomechanical stability of phase-segregated lipid bilayers consisting of dioleoylphosphatidylcholine/sphingomyelin/cholesterol (DOPC/SM/Chol) by means of atomic force microscopy (AFM) imaging and force mapping. Breakthrough forces were consistently higher in the SM/Chol-enriched liquid-ordered domains (Lo) than in the DOPC-enriched fluid-disordered phase (Ld) at a series of loading rates. We also report the activation energies (DEa) for the formation of an AFM-tip-induced fracture, calculated by a model for the rupture of molecular thin films. The obtained DEa values agree remarkably well with reported values for fusion-related processes using other techniques. Furthermore, we observed that within the Chol range studied, the lateral organization of bilayers can be categorized into three distinct groups. The results are rationalized by fracture nanomechanics of a ternary phospholipid/sphingolipid/cholesterol mixture using correlated AFM-based imaging and force mapping, which demonstrates the influence of a wide range of cholesterol content on the morphology and nanomechanical stability of model bilayers. This provides fundamental insights into the role of cholesterol in the formation and stability of sphingolipid/cholesterol-enriched domains, as well as in membrane fusion.
Publication date
In
  • Biophysical Journal 99, no. 2 (21 July 2010): 507–516.
LanguageEnglish
Peer reviewedYes
NRC publication
This is a non-NRC publication

"Non-NRC publications" are publications authored by NRC employees prior to their employment by NRC.

NPARC number17178176
Export citationExport as RIS
Report a correctionReport a correction (opens in a new tab)
Record identifier904b674c-5cb5-446f-9f3c-63efb997fad1
Record created2011-03-15
Record modified2020-04-17
Date modified: